Judgment of 2 February 2018

INTERNATIONAL COURT OF JUSTICE
YEAR 2018
2018
2 February
General List
Nos. 157 and 165
2 February 2018
MARITIME DELIMITATION IN THE CARIBBEAN SEA
AND THE PACIFIC OCEAN
(COSTA RICA v. NICARAGUA)
and
LAND BOUNDARY IN THE NORTHERN PART OF
ISLA PORTILLOS
(COSTA RICA v. NICARAGUA)
Jurisdiction of the Court.
* *
General background.
Geography — Land boundary between Parties spanning Central American isthmus —
Isla Portillos, San Juan River and Harbor Head Lagoon — Features off the Caribbean coast —
Description of Pacific coast.
Historical context — 1858 Treaty of Limits — Cleveland Award — Alexander Awards —
Starting segment of land boundary in First Alexander Award — Geomorphological changes —
Court’s finding on sovereignty in 2015 Judgment — Negotiations between the Parties concerning
maritime delimitations.
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Maritime delimitations in the Caribbean Sea and Pacific Ocean — 1980 delimitation treaty
between Costa Rica and Panama — 1977 delimitation treaty between Costa Rica and Colombia,
not ratified by Costa Rica — Court’s 2007 Judgment concerning Nicaraguan maritime boundary
with Honduras — Court’s 2012 Judgment concerning Nicaraguan maritime boundary with
Colombia — 1976 delimitation treaty between Colombia and Panama.
* *
Land boundary in the northern part of Isla Portillos.
Issues concerning territorial sovereignty.
Principle of res judicata — Paragraphs 69-70 of the Court’s 2015 Judgment — Question of
sovereignty over coast of northern part of Isla Portillos expressly excluded — Issue thus not res
judicata — Nicaragua’s claim concerning sovereignty admissible.
2015 Judgment finding territory under Costa Rican sovereignty extends to right bank of
San Juan River at its mouth — Uncertainties about configuration of coast of Isla Portillos in
2015 — Assessment of Court-appointed experts — No longer any water channel connecting
San Juan River and Harbor Head Lagoon — Costa Rica has sovereignty over whole of
Isla Portillos except enclave of Harbor Head Lagoon and sandbar separating it from sea, over
which Nicaragua has sovereignty — Starting-point of land boundary currently at end of sandspit at
mouth of San Juan River — Extent of sandbar as measured by experts — Course of land boundary
for enclave of Harbor Head Lagoon.
*
Alleged violations of Costa Rica’s sovereignty — Military camp not on sandbar appertaining
to Nicaragua — Installation of military camp violated Costa Rica’s sovereignty — Camp must be
removed from Costa Rican territory — No breach of 2015 Judgment — Declaration of breach of
sovereignty and order to remove camp constitute appropriate reparation.
* *
Maritime delimitation in the Caribbean Sea.
- 3 -
Starting-point — Divergent views of the Parties — Instability of the coastline near mouth of
River — Impossibility to identify on sandspit a fixed starting-point for maritime delimitation — Use
of fixed point at sea — Mobile line connecting fixed point to coast — Coastal recession as
prevailing phenomenon — Two nautical miles appropriate distance from coast for fixed point.
*
Delimitation of the territorial sea — Two-stage procedure — First stage, construction of
provisional median line — Only base points on natural coast and solid land used — Second stage,
consideration whether special circumstances justify adjustment of median line —
Concavity/convexity of coast near starting-point not a special circumstance — Instability and
narrowness of sandspit at mouth of river is a special circumstance — Appropriateness of mobile
line between fixed point at sea and point on solid land on Costa Rican coast closest to mouth of
river — Present location of mobile line — Instability of sandbar separating Harbor Head Lagoon
from sea is a special circumstance — Delimitation of territorial sea will not take into account any
entitlement which might result from enclave of Harbor Head Lagoon — Course of delimitation line
in territorial sea.
*
Delimitation of the exclusive economic zone and continental shelf.
Relevant coasts — Entire mainland coast of Costa Rica relevant — Mainland coast of
Nicaragua up to Punta Gorda (north) relevant — Coasts of Corn Islands that do not face north
also relevant — Coasts of Cayos de Perlas not relevant — Coastal lengths measured according to
natural configuration.
Relevant area — Limits of relevant area in the north — Claims of third States in the south.
Relevance of bilateral treaties and judgments involving third States — 1976 treaty between
Panama and Colombia not relevant between the Parties — With regard to 1977 treaty between
Costa Rica and Colombia, any possible renunciation of maritime entitlements by Costa Rica not
shown to be renunciation in favour of other States.
Methodology of delimitation of the exclusive economic zone and continental shelf in three
stages — First stage, construction of provisional equidistance line — Second stage, determination
whether relevant circumstances justify adjustment of equidistance line — Third stage, verification
of absence of marked disproportionality.
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Provisional equidistance line — Determination of base points — Natural coast and solid
land used for base points — Base points on Corn Islands — Base points on Paxaro Bovo and
Palmenta Cays — Line without prejudice to any claims of third States — Course of provisional
equidistance line.
Adjustment to provisional equidistance line — Corn Islands given half effect —
Concavity/convexity of coast near Punta de Castilla not a relevant circumstance — Overall
concavity of Costa Rica’s coast not a relevant circumstance — No significant cut-off of
Costa Rica’s projections once half effect given to Corn Islands — Course of adjusted equidistance
line — Line without prejudice to any claims of third States — Adoption of simplified line on the
basis of most significant turning points — Course of simplified line.
Disproportionality test — No need to achieve strict proportionality — Impossible to
calculate relevant area precisely due to potential claims of third States — Approximate calculation
sufficient to test for gross disproportion — Calculation based on notional extension of
Costa Rica-Panama boundary — No disproportionality such as to create an inequitable result.
* *
Maritime delimitation in the Pacific Ocean.
Starting-point — Parties agreement to use midpoint of closing line of Salinas Bay — Precise
co-ordinates of that point.
*
Delimitation of the territorial sea — Parties agree on base points for construction of
provisional median line — Court adopts base points selected by Parties — Santa Elena Peninsula
not a special circumstance justifying adjustment of median line — Course of delimitation line in
territorial sea.
*
Delimitation of the exclusive economic zone and continental shelf.
Relevant coasts — Relevant coasts of both Parties identified using straight lines — Entire
Nicaraguan coast relevant — Costa Rican coast running along straight lines connecting
Punta Zacate, Punta Santa Elena, Cabo Velas, Punta Guiones and Cabo Blanco relevant —
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Costa Rican coast running along straight lines connecting Punta Herradura, Osa Peninsula,
Punta Llorona and Punta Salsipuedes also relevant — Coasts of Nicoya Gulf not relevant —
Coastal lengths measured along straight lines.
Relevant area — Limits of relevant area in north — Limits of relevant area in west and
south.
Provisional equidistance line — Parties agree on base points — Court adopts base points
selected by Parties — Course of provisional equidistance line.
Adjustment to provisional equidistance line — Santa Elena Peninsula given half effect —
Nicoya Peninsula not a relevant circumstance justifying adjustment — Course of adjusted
equidistance line — Adoption of simplified line on the basis of most significant turning points —
Course of simplified line.
Disproportionality test — No disproportionality such as to create an inequitable result.
JUDGMENT
Present: President ABRAHAM; Vice-President YUSUF; Judges OWADA, TOMKA, BENNOUNA,
CANÇADO TRINDADE, GREENWOOD, XUE, DONOGHUE, GAJA, SEBUTINDE,
BHANDARI, ROBINSON, GEVORGIAN; Judges ad hoc SIMMA, AL-KHASAWNEH;
Registrar COUVREUR.
In the case concerning maritime delimitation in the Caribbean Sea and the Pacific Ocean,
and in the joined case (see paragraph 29 below) concerning the land boundary in the northern part
of Isla Portillos,
between
the Republic of Costa Rica,
represented by
H.E. Mr. Manuel A. González Sanz, Minister for Foreign Affairs and Worship;
H.E. Mr. Edgar Ugalde Álvarez, Ambassador on Special Mission,
as Agent;
H.E. Mr. Sergio Ugalde, Ambassador of Costa Rica to the Kingdom of the Netherlands,
Member of the Permanent Court of Arbitration,
as Co-Agent, Counsel and Advocate;
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Mr. Marcelo Kohen, Professor of International Law at the Graduate Institute of International
and Development Studies, Geneva, member and Secretary-General of the Institut de droit
international,
Mr. Samuel Wordsworth, Q.C., member of the English Bar, member of the Paris Bar, Essex
Court Chambers,
Mr. Coalter G. Lathrop, member of the North Carolina Bar, Sovereign Geographic,
Mr. Arnoldo Brenes, member of the Costa Rican Bar, Senior Adviser to the Ministry of
Foreign Affairs and Worship,
Ms Kate Parlett, member of the English Bar, 20 Essex Street,
Ms Katherine Del Mar, member of the English Bar, 4 New Square, Lincoln’s Inn,
as Counsel and Advocates;
Mr. Simon Olleson, member of the English Bar, Three Stone,
as Counsel;
Mr. Ricardo Otarola, Adviser to the Ministry of Foreign Affairs and Worship,
Ms Ana Patricia Villalobos, chargé d’affaires, Embassy of Costa Rica to Venezuela,
Ms Alejandra González, Minister Counsellor and Consul General of Costa Rica in the
Kingdom of the Netherlands,
Mr. Christian Kandler, Minister Counsellor at the Costa Rican Embassy in the Kingdom of
the Netherlands,
Mr. Najib Messihi, Ph.D. candidate, Graduate Institute of International and Development
Studies, Geneva,
as Assistant Counsel;
Ms Ericka Araya, administrative assistant at the Embassy of Costa Rica in the Kingdom of
the Netherlands,
as Assistant,
and
the Republic of Nicaragua,
represented by
H.E. Mr. Carlos José Argüello Gómez, Ambassador of Nicaragua to the Kingdom of the
Netherlands, member of the International Law Commission,
as Agent and Counsel;
- 7 -
Mr. Vaughan Lowe, Q.C., member of the English Bar, Essex Court Chambers, Emeritus
Professor of International Law, Oxford University, member of the Institut de droit
international,
Mr. Lawrence H. Martin, Attorney at Law, Foley Hoag LLP, member of the Bars of the
United States Supreme Court, the District of Columbia and the Commonwealth of
Massachusetts,
Mr. Alex Oude Elferink, Director, Netherlands Institute for the Law of the Sea, Professor of
International Law of the Sea, Utrecht University,
Mr. Paul Reichler, Attorney at Law, Foley Hoag LLP, member of the Bars of the
United States Supreme Court and the District of Columbia,
Mr. Antonio Remiro Brotóns, Professor of International Law, Universidad Autónoma de
Madrid, member of the Institut de droit international,
Mr. Benjamin Samson, Ph.D. candidate, Centre de droit international de Nanterre (CEDIN),
University Paris Nanterre, Visiting Scholar, George Washington University Law School,
as Counsel and Advocates;
Mr. Alain Pellet, Emeritus Professor at the University Paris Nanterre, former member and
former Chairman of the International Law Commission, member of the Institut de droit
international,
Mr. Walner Molina Pérez, Juridical Adviser, Ministry of Foreign Affairs,
Mr. Julio César Saborio, Juridical Adviser, Ministry of Foreign Affairs,
Ms Tania Elena Pacheco Blandino, Juridical Adviser, Ministry of Foreign Affairs,
Mr. Edgardo Sobenes Obregon, Counsellor, Embassy of Nicaragua in the Kingdom of the
Netherlands,
Ms Claudia Loza Obregon, Legal Adviser, Ministry of Foreign Affairs,
Mr. Yuri Parkhomenko, Attorney at Law, Foley Hoag LLP,
as Counsel;
Ms Gimena González, Researcher in public international law,
Ms Ilona Tan, Legal Intern, Foley Hoag LLP,
as Legal Assistants;
Mr. Robin Cleverly, M.A., D.Phil, C.Geol, FGS, Law of the Sea Consultant, Marbdy
Consulting Ltd,
- 8 -
Ms Victoria Leader, Geographical and Technical Consultant,
as Scientific and Technical Advisers;
Ms Sherly Noguera de Argüello, Consul General and Minister Counsellor of the Republic of
Nicaragua in the Kingdom of the Netherlands,
as Administrator,
THE COURT,
composed as above,
after deliberation,
delivers the following Judgment:
1. By an Application filed in the Registry of the Court on 25 February 2014, the Republic of
Costa Rica (hereinafter “Costa Rica”) instituted proceedings against the Republic of Nicaragua
(hereinafter “Nicaragua”) with regard to a dispute concerning the “establishment of single maritime
boundaries between the two States in the Caribbean Sea and the Pacific Ocean, respectively,
delimiting all the maritime areas appertaining to each of them, in accordance with the applicable
rules and principles of international law” (hereinafter the “case concerning Maritime
Delimitation”).
2. In its Application, Costa Rica seeks to found the jurisdiction of the Court on the
declaration it made on 20 February 1973 under Article 36, paragraph 2, of the Statute of the Court,
as well as on the declaration which Nicaragua made on 24 September 1929 (and amended on
23 October 2001) under Article 36 of the Statute of the Permanent Court of International Justice
and which is deemed, pursuant to Article 36, paragraph 5, of the Statute of the present Court, for
the period which it still has to run, to be acceptance of the compulsory jurisdiction of this Court.
Costa Rica further invokes as a basis for the Court’s jurisdiction Article XXXI of the American
Treaty on Pacific Settlement adopted at Bogotá on 30 April 1948 (hereinafter the “Pact of
Bogotá”).
3. In accordance with Article 40, paragraph 2, of the Statute, the Registrar communicated a
signed copy of the Application forthwith to the Government of Nicaragua; and, under paragraph 3
of that Article, all States entitled to appear before the Court were notified of the filing of the
Application.
4. Pursuant to the instructions of the Court under Article 43 of its Rules, the Registrar
addressed to States parties to the United Nations Convention on the Law of the Sea of
10 December 1982 (hereinafter “UNCLOS”) the notifications provided for in Article 63,
paragraph 1, of the Statute. The Registrar also addressed the notification provided for in Article 43,
paragraph 2, of the Rules of Court to the European Union, which is also party to the said
Convention, asking whether it intended to submit any observations under that provision.
- 9 -
5. Since the Court included upon the Bench no judge of the nationality of either Party, each
of them availed itself of its right under Article 31, paragraph 3, of the Statute to choose a
judge ad hoc in the case. Costa Rica chose Mr. Bruno Simma and Nicaragua chose
Mr. Awn Shawkat Al-Khasawneh.
6. By an Order dated 1 April 2014, the Court fixed 3 February 2015 and 8 December 2015 as
the respective time-limits for the filing of a Memorial by Costa Rica and a Counter-Memorial by
Nicaragua. The Memorial and the Counter-Memorial were filed within the time-limits thus fixed.
7. By letter dated 3 February 2015 and received in the Registry on 5 February 2015, the
Government of the Republic of Colombia, referring to Article 53, paragraph 1, of the Rules of
Court, made a request to be furnished with copies of the pleadings and documents annexed in the
case. After consulting the Parties in accordance with that same provision, the President of the Court
decided to grant that request. By letters dated 30 March 2015, the Registrar duly communicated
that decision to the Government of Colombia and to the Parties.
By letter dated 5 August 2015, received in the Registry on 7 August 2015, the Government
of the Republic of Panama, referring to Article 53, paragraph 1, of the Rules of Court, in turn made
a request to be furnished with copies of the pleadings and documents annexed in the case. After
consulting the Parties in accordance with that same provision, the President of the Court decided to
grant that request. By letters dated 26 August 2015, the Registrar duly communicated that decision
to the Government of Panama and to the Parties.
8. At a meeting held by the President with the representatives of the Parties on 28 January
2016, the Parties agreed that it was not necessary to file a Reply and a Rejoinder.
9. By letters dated 26 February 2016, the Registrar informed the Parties that the Court, in
accordance with Article 54, paragraph 1, of the Rules of Court, had fixed 5 December 2016 as the
date for the opening of the oral proceedings in the case.
10. By letters dated 13 April 2016, the Registrar informed the Parties, pursuant to Article 67,
paragraph 1, of the Rules of Court, that the Court was considering arranging for an expert opinion
entrusted to one or several experts. The experts would be asked to collect, by conducting a site
visit, all the factual elements capable of allowing for the determination of the starting-point of the
maritime boundary between the Parties in the Caribbean Sea, in particular elements relating to the
state of the coast between the point located on the right bank of the San Juan River at its mouth and
the land point closest to Punta de Castilla, as those two points could be identified at the time of that
visit. The Parties were further informed that the Court had fixed 3 May 2016 as the time-limit
within which they might present their positions with respect to any such appointment, in particular
their views on the subject of the expert opinion, the number and mode of appointment of the
experts, and the procedure to be followed. They were also advised that any comments that either
Party might wish to make on the reply of the other Party should be furnished by 13 May 2016 at the
latest.
- 10 -
11. By letter dated 3 May 2016, Costa Rica welcomed the exercise by the Court of its power
to arrange for an expert opinion. It suggested that the Court consider appointing a committee of
three experts, composed of geographers who were independent of both Parties, and that the Parties
should have the opportunity to make observations on the choice of these experts. Costa Rica
proposed that a number of matters be covered in the terms of reference for the experts. It also
expressed the wish that the Parties should have the opportunity to provide comments on the
experts’ report in writing before the beginning of the oral proceedings, and that any comments that
either Party might wish to make on the comments of the other Party should also be provided in
writing in advance of the oral proceedings. Finally, Costa Rica made certain proposals regarding
logistical matters.
12. By letter of the same date, Nicaragua, for its part, stated that it considered that there was
no need to carry out a site visit, asserting that, since the location of the starting-point of the land
boundary on the Caribbean coast had been established by various instruments, the determination of
the starting-point of the maritime boundary between the Parties was a technical and legal task that
did not require a site visit. Nicaragua nonetheless added that if, having taken into account its
position, the Court were to consider that a site visit was necessary, Nicaragua would be ready to
express in due time its position with respect to the terms of reference for the expert(s) and their
appointment, and to assist them to the fullest possible extent.
13. By letters of 13 May 2016, each of the Parties reiterated its position.
14. By Order dated 31 May 2016, the Court decided that an expert opinion would be
arranged, in accordance with Articles 48 and 50 of its Statute, to inform the Court as to the state of
the coast between the point suggested by Costa Rica and the point suggested by Nicaragua in their
pleadings as the starting-point of the maritime boundary in the Caribbean Sea. The Order stated,
inter alia, that the expert opinion would be entrusted to two independent experts appointed by
Order of the President of the Court after hearing the Parties, and that these experts would make the
following declaration:
“I solemnly declare, upon my honour and conscience, that I will perform my
duties as expert honourably and faithfully, impartially and conscientiously, and will
refrain from divulging or using, outside the Court, any documents or information of a
confidential character which may come to my knowledge in the course of the
performance of my task.”
15. By letters dated 2 June 2016, the Registrar informed the Parties of the Court’s decision.
He also indicated that the Court had identified two potential experts to prepare the expert opinion it
had decided to obtain, namely Mr. Eric Fouache and Mr. Francisco Gutiérrez, whose curricula vitae
were enclosed with the said letters. The Parties were invited to communicate to the Court any
observations they might have on the two experts by 10 June 2016, at the latest.
16. By letter dated 10 June 2016, Costa Rica stated that it had no objection to the experts
selected by the Court and that it stood ready to provide any necessary assistance to the expert
mission; by letter of the same date, Nicaragua, without submitting any specific observations on the
two experts, expressed its full readiness to assist the Court with the organization of the mission.
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17. By an Order dated 16 June 2016, the President of the Court appointed the following two
experts: Mr. Eric Fouache, of French nationality, Professor of Geography, Vice-Chancellor of
Paris-Sorbonne University Abu Dhabi (United Arab Emirates), senior member of the
Institut universitaire de France and President of the International Association of Geomorphologists;
and Mr. Francisco Gutiérrez, of Spanish nationality, Professor of Geology and Geomorphology at
the University of Zaragoza (Spain), former member of the Executive Committee of the
International Association of Geomorphologists. The experts subsequently made the solemn
declaration provided for in the Order of 31 May 2016 (see paragraph 14 above).
18. The experts informed the Court that, in their view, it would be necessary to conduct two
site visits, one in early December (rainy period with high discharge of the San Juan River) and the
other in March or early April (drier period with low discharge of the San Juan River).
Consequently, the Court decided to postpone the opening of the oral proceedings until 12 June
2017. The Parties were informed of this decision by letters from the Registrar dated 1 July 2016.
19. Between July and November 2016, several exchanges of correspondence took place
between the experts, the Registrar and the Parties concerning the organization of the site visits. In
addition, on 1 September 2016, the Registrar met with the representatives of the Parties to discuss
the practical aspects of the visits. By letters dated 20 October 2016, the Parties communicated to
the Court several documents requested by the experts (photographs, satellite images, maps, etc.);
these documents were transmitted to them forthwith.
20. By letter dated 28 November 2016, Costa Rica requested the postponement of the
experts’ first site visit, which had been scheduled to take place from 4 to 9 December 2016, in light
of the damage caused by Hurricane Otto, which shortly beforehand had hit the region to be
inspected. By letter dated 29 November 2016, Nicaragua indicated its preference for the mission to
proceed as planned. By letter dated 30 November 2016, Costa Rica reiterated its request, while
setting out the arrangements that could be provided if the Court were to decide to maintain the
dates of the visit scheduled for early December. The experts were consulted and they expressed
their reluctance to postpone the mission, explaining in particular that visiting at that time would
allow them to have a better grasp of the impact of high-magnitude hydrological events on the
configuration of the coast and the San Juan River. The President of the Court having considered the
matter, it was decided to maintain the dates of the site visit as planned.
21. The experts’ first site visit accordingly took place from 4 to 9 December 2016. The
experts were accompanied by two staff members of the Registry who constituted the secretariat of
the mission, and by a delegation from each Party. During the visit, the Parties exchanged
documents, photographs and video recordings and provided them to the experts. They subsequently
indicated that they considered that such new materials exchanged during the visits should be
included in the case file, unless otherwise stated.
22. On 16 January 2017, Costa Rica instituted proceedings against Nicaragua in a dispute
concerning “the precise location of the land boundary separating the Los Portillos/Harbor Head
Lagoon sandbar from Isla Portillos” and “the . . . establishment of a military camp by Nicaragua on
the beach of Isla Portillos” (hereinafter “the case concerning the Northern Part of Isla Portillos”).
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Costa Rica seeks to found the jurisdiction of the Court on the aforementioned declarations
(see paragraph 2 above) and on Article XXXI of the Pact of Bogotá.
23. In its Application, Costa Rica requested that the Court join the new proceedings with the
proceedings in the case concerning Maritime Delimitation, pursuant to Article 47 of the Rules of
Court.
24. In accordance with Article 40, paragraph 2, of the Statute, the Registrar communicated a
signed copy of the said Application forthwith to the Government of Nicaragua; under paragraph 3
of that Article, all States entitled to appear before the Court were notified of the filing of the
Application.
25. Since the Court included upon the Bench no judge of the nationality of either Party, each
of them availed itself of its right under Article 31, paragraph 3, of the Statute to choose a
judge ad hoc in the case concerning the Northern Part of Isla Portillos. Costa Rica chose
Mr. Bruno Simma and Nicaragua chose Mr. Awn Shawkat Al-Khasawneh.
26. On 25 January 2017, the Registrar held a meeting with the representatives of Costa Rica
and Nicaragua in connection with the case concerning Maritime Delimitation to discuss
arrangements for the second site visit. During that meeting, it was decided that the said visit would
take place from 12 to 17 March 2017.
27. On 26 January 2017, the President held a meeting with the representatives of Costa Rica
and Nicaragua, who were invited to convey the views of their Governments on the question of the
time-limits for the filing of pleadings in the case concerning the Northern Part of Isla Portillos and
on whether it would be appropriate to join the proceedings in that case with those in the case
concerning Maritime Delimitation.
28. By Order dated 2 February 2017, the Court fixed 2 March 2017 and 18 April 2017 as the
respective time-limits for the filing of a Memorial by Costa Rica and a Counter-Memorial by
Nicaragua in the case concerning the Northern Part of Isla Portillos. The Memorial and the
Counter-Memorial were filed within the time-limits thus prescribed.
29. By its Order dated 2 February 2017, the Court also decided to join the proceedings in the
case concerning Maritime Delimitation and the case concerning the Northern Part of Isla Portillos.
30. By letters dated 3 February 2017, the Registrar informed the Parties that the Court had
decided that the hearings in the joined cases would open on 3 July 2017.
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31. The experts’ second site visit took place from 12 to 17 March 2017. The experts were
once again accompanied by two staff members of the Registry and a delegation from each Party.
During the visit, the Parties exchanged documents, photographs and video recordings and provided
them to the experts.
32. By letter dated 1 May 2017, the Registrar communicated to the Parties copies of the
report filed by the experts appointed in the case concerning Maritime Delimitation. Each of the
Parties was given until 1 June 2017 to submit any written observations that they might wish to
make on the said report.
33. On 16 May 2017, the President held a meeting with the representatives of the Parties to
discuss the organization of the oral proceedings in the joined cases; the Parties agreed that they did
not consider it necessary to put any questions to the experts at the hearings. By letters dated
29 May 2017, the Registrar informed the Parties of the schedule for the oral proceedings, as
adopted by the Court.
34. Under cover of a letter dated 1 June 2017, Costa Rica communicated to the Court the
written observations of its Government on the experts’ report. By letter of the same date, Nicaragua
indicated that it had no written observations to make at that stage. Costa Rica’s observations were
communicated to the experts, who responded in writing on 8 June 2017; that response was
transmitted to the Parties forthwith.
35. By letters dated 12 June 2017, the Registrar communicated to the experts the text of a
question from a Member of the Court, and notified the Parties of that question. The experts replied
on 15 June 2017; their reply was transmitted to the Parties.
36. By letters dated 28 June 2017, the Registrar communicated to the Parties the text of a
question from the Court addressed to them both. The Parties were invited to present their responses
during the first round of oral argument.
*
37. In accordance with Article 53, paragraph 2, of its Rules, the Court decided, after
consulting the Parties, that copies of the pleadings and documents annexed, as well as the experts’
report and certain related documents, would be made accessible to the public on the opening of the
oral proceedings.
38. Public hearings were held from Monday 3 July to Thursday 13 July 2017 in the joined
proceedings. The Court heard the oral arguments and replies of:
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For Costa Rica: H.E. Mr. Edgar Ugalde Álvarez,
H.E. Mr. Sergio Ugalde,
Ms Kate Parlett,
Mr. Samuel Wordsworth,
Mr. Marcelo Kohen,
Ms Katherine Del Mar,
Mr. Arnoldo Brenes,
Mr. Coalter Lathrop.
For Nicaragua: H.E. Mr. Carlos José Argüello Gómez,
Mr. Alex Oude Elferink,
Mr. Antonio Remiro Brotóns,
Mr. Vaughan Lowe,
Mr. Paul Reichler,
Mr. Benjamin Samson,
Mr. Lawrence H. Martin.
* *
39. In its Application in the case concerning Maritime Delimitation, Costa Rica made the
following requests:
“Accordingly, the Court is asked to determine the complete course of a single
maritime boundary between all the maritime areas appertaining, respectively, to
Costa Rica and to Nicaragua in the Caribbean Sea and in the Pacific Ocean, on the
basis of international law.
Costa Rica further requests the Court to determine the precise geographical
co-ordinates of the single maritime boundaries in the Caribbean Sea and in the
Pacific Ocean.”
40. In the course of the written proceedings in the case concerning Maritime Delimitation,
the following submissions were presented by the Parties:
On behalf of the Government of Costa Rica,
in the Memorial:
“Costa Rica respectfully requests the Court to determine the complete course of
single maritime boundaries between all the maritime areas appertaining, respectively,
to Costa Rica and to Nicaragua in the Pacific Ocean and in the Caribbean Sea, on the
basis of international law.
Costa Rica further requests the Court to determine the precise geographical
co-ordinates of the single maritime boundaries in the Pacific Ocean and in the
Caribbean Sea, as follows:
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1. to delimit the maritime areas of Costa Rica and Nicaragua in the Pacific Ocean by
a boundary connecting with geodetic lines the points with the following
co-ordinates:
Point number Latitude north (DMS)
(WGS 84)
Longitude west (DMS)
(WGS 84)
SP-P (Starting-Point – Pacific) 11° 04' 00.0" 85° 44' 28.0"
1 11° 03' 57.6" 85° 45' 30.3"
2 11° 03' 57.7" 85° 45' 35.9"
3 11° 03' 47.2" 85° 46' 31.7"
4 11° 03' 53.8" 85° 47' 13.4"
5 11° 03' 24.2" 85° 49' 43.5"
6 11° 03' 17.9" 85° 50' 05.1"
7 11° 02' 45.0" 85° 51' 25.2"
8 11° 03' 11.6" 85° 52' 42.8"
9 11° 04' 26.8" 85° 55' 28.3"
10 11° 05' 13.7" 85° 57' 21.2"
11 11° 05' 51.6" 86° 00' 48.1"
12 11° 05' 54.2" 86° 04' 31.5"
13 11° 06' 22.0" 86° 07' 00.4"
14 11° 05' 45.4" 86° 13' 10.2"
15 11° 05' 43.7" 86° 13' 28.7"
16 11° 05' 30.9" 86° 15' 09.8"
17 11° 04' 22.2" 86° 21' 43.8"
18 11° 03' 32.6" 86° 25' 21.2"
19 10° 56' 56.3" 86° 44' 27.0"
20 10° 54' 22.7" 86° 49' 39.5"
21 10° 36' 50.6" 87° 22' 47.6"
22 10° 21' 23.2" 87° 47' 15.3"
23
(intersection with 200-M limit)
09° 43' 05.7" 89° 11' 23.5"
2. to delimit the maritime areas of Costa Rica and Nicaragua in the Caribbean Sea by
a boundary connecting with geodetic lines the points with the following
co-ordinates:
Point number Latitude north (DMS)
(WGS 84)
Longitude west (DMS)
(WGS 84)
SP-C (Starting-Point – Caribbean) 10° 56' 26.0" 83° 41' 53.0"
1 10° 56' 54.0" 83° 42' 03.7"
2 10° 57' 16.6" 83° 41' 58.4"
- 16 -
3 11° 02' 12.6" 83° 40' 27.1"
4 11° 02' 54.7" 83° 40' 01.0"
5 11° 03' 04.8" 83° 39' 54.1"
6 11° 03' 46.1" 83° 39' 29.6"
7 11° 03' 47.4" 83° 39' 28.7"
8 11° 05' 35.2" 83° 38' 14.0"
9 11° 07' 47.2" 83° 36' 33.2"
10 11° 10' 16.0" 83° 34' 13.2"
11 11° 10' 39.2" 83° 33' 47.3"
12 11° 13' 42.6" 83° 30' 33.9"
13 11° 15' 02.0" 83° 28' 53.6"
14
(intersection with Costa Rica
200-M limit)
12° 19' 15.9" 80° 33' 59.2"”
On behalf of the Government of Nicaragua,
in the Counter-Memorial:
“For the reasons given in the present Counter-Memorial, the Republic of
Nicaragua requests the Court to adjudge and declare that:
1. In the Pacific Ocean, the maritime boundary between the Republic of Nicaragua
and the Republic of Costa Rica starts at a point with co-ordinates 11° 03' 56.3" N,
85° 44' 28.3" W and follows geodetic lines connecting the points with
co-ordinates:
Points Latitude Longitude
P-1 11° 03' 57.6" N 85° 45' 27.0" W
P-2 11° 03' 57.8" N 85° 45' 36.8" W
P-3 11° 03' 47.6" N 85° 46' 34.0" W
P-4 11° 03' 54" N 85° 47' 13.2" W
P-5 11° 03' 25" N 85° 49' 42.4" W
P-6 11° 03' 17.7" N 85° 50' 06.3" W
P-7 11° 02' 44.8" N 85° 51' 25.2" W
P-8 (12 NM) 10° 54' 51.7" N 86° 10' 14.6" W
P-9 10° 50' 59.1" N 86° 21' 37.6" W
P-10 10° 41' 24.4" N 86° 38' 0.8" W
P-11 10° 19' 28.3" N 87° 11' 0.7" W
P-12 9° 53' 09.0" N 87° 47' 48.8" W
P-13 (200 NM) 9° 16' 27.5" N 88° 46' 10.9" W
- 17 -
2. In the Caribbean Sea, the maritime boundary between the Republic of Nicaragua
and the Republic of Costa Rica starts at a point with co-ordinates 10° 55' 49.7" N
and 83° 40' 0.6" W and follow[s] geodetic lines connecting the points with
co-ordinates:
Points Latitude Longitude
C-1 10° 59' 21.3" N 83° 31' 6.9" W
C-1a (12 NM) 11° 00' 18.9" N 83° 27' 38.0" W
C-2 11° 01' 9.9" N 83° 24' 26.9" W
C-3 11° 05' 33.7" N 83° 03' 59.2" W
C-4 11° 11' 08.4" N 82° 34' 41.8" W
C-5 11° 05' 0.7" N 82° 18' 52.3" W
C-6 11° 05' 05.2" N 82° 14' 0.0" W
C-7 10° 49' 0.0" N 82° 14' 0.0" W
C-8 10° 49' 0.0" N 81° 26' 8.2" W
(All co-ordinates are referred to WGS 84 datum.)”
41. At the oral proceedings in the joined cases, the following submissions were presented by
the Parties with respect to the case concerning Maritime Delimitation:
On behalf of the Government of Costa Rica,
at the hearing of 10 July 2017:
“Costa Rica respectfully requests the Court, rejecting all submissions made by
Nicaragua:
1. To determine, on the basis of international law, the complete course of single
maritime boundaries between all the maritime areas appertaining, respectively, to
Costa Rica and to Nicaragua in the Pacific Ocean and in the Caribbean Sea.
2. To determine the precise geographical co-ordinates of the single maritime
boundaries in the Pacific Ocean and in the Caribbean Sea, and in particular:
(a) to delimit the maritime areas of Costa Rica and Nicaragua in the
Pacific Ocean by a boundary connecting with geodetic lines the points with
the following co-ordinates:
Point number Latitude (DMS)
(WGS 84)
Longitude (DMS)
(WGS 84)
SP-P (Starting-Point – Pacific) 11° 04' 00.0" N 85° 44' 28.0" W
1 11° 03' 57.6" N 85° 45' 30.3" W
2 11° 03' 57.7" N 85° 45' 35.9" W
- 18 -
Point number Latitude (DMS)
(WGS 84)
Longitude (DMS)
(WGS 84)
3 11° 03' 47.2" N 85° 46' 31.7" W
4 11° 03' 53.8" N 85° 47' 13.4" W
5 11° 03' 24.2" N 85° 49' 43.5" W
6 11° 03' 17.9" N 85° 50' 05.1" W
7 11° 02' 45.0" N 85° 51' 25.2" W
8 11° 03' 11.6" N 85° 52' 42.8" W
9 11° 04' 26.8" N 85° 55' 28.3" W
10 11° 05' 13.7" N 85° 57' 21.2" W
11 11° 05' 51.6" N 86° 00' 48.1" W
12 11° 05' 54.2" N 86° 04' 31.5" W
13 11° 06' 22.0" N 86° 07' 00.4" W
14 11° 05' 45.4" N 86° 13' 10.2" W
15 11° 05' 43.7" N 86° 13' 28.7" W
16 11° 05' 30.9" N 86° 15' 09.8" W
17 11° 04' 22.2" N 86° 21' 43.8" W
18 11° 03' 32.6" N 86° 25' 21.2" W
19 10° 56' 56.3" N 86° 44' 27.0" W
20 10° 54' 22.7" N 86° 49' 39.5" W
21 10° 36' 50.6" N 87° 22' 47.6" W
22 10° 21' 23.2" N 87° 47' 15.3" W
23
(intersection with 200-M limit)
09° 43' 05.7" N 89° 11' 23.5" W
(b) to delimit the maritime areas of Costa Rica and Nicaragua in the
Caribbean Sea by a boundary connecting with geodetic lines the points with
the following co-ordinates:
Point number Latitude (DMS)
(WGS 84)
Longitude (DMS)
(WGS 84)
SP-C (Starting-Point –
Caribbean)
10° 56' 22.1" N 83° 41' 51.4" W
1 10° 56' 54.0" N 83° 42' 03.7" W
2 10° 57' 16.6" N 83° 41' 58.4" W
3 11° 02' 12.6" N 83° 40' 27.1" W
- 19 -
Point number Latitude (DMS)
(WGS 84)
Longitude (DMS)
(WGS 84)
4 11° 02' 54.7" N 83° 40' 01.0" W
5 11° 03' 04.8" N 83° 39' 54.1" W
6 11° 03' 46.1" N 83° 39' 29.6" W
7 11° 03' 47.4" N 83° 39' 28.7" W
8 11° 05' 35.2" N 83° 38' 14.0" W
9 11° 07' 47.2" N 83° 36' 33.2" W
10 11° 10' 16.0" N 83° 34' 13.2" W
11 11° 10' 39.2" N 83° 33' 47.3" W
12 11° 13' 42.6" N 83° 30' 33.9" W
13 11° 15' 02.0" N 83° 28' 53.6" W
14
(intersection with Costa Rica’s
200-M limit)
12° 19' 15.9" N 80° 33' 59.2" W
(c) as a subsidiary submission to paragraph (b) above, to delimit the maritime
areas of Costa Rica and Nicaragua in the Caribbean Sea by a boundary:
(i) connecting, using a geodetic line, the point 3 nautical miles from the
Parties’ respective coasts (Point FP1, having co-ordinates
10° 59' 22.7" N, 83° 41' 19.0" W), with Point 3 in paragraph (b) above;
(ii) thereafter, connecting, with geodetic lines Points 3 to 14 in paragraph (b)
above;
(iii) in the initial sector, connecting, using a geodetic line, Point FP1 and the
point constituting the low-water mark on the right bank of the
San Juan River at its mouth, as it may exist from time to time.”
On behalf of the Government of Nicaragua,
at the hearing of 13 July 2017:
“Nicaragua respectfully requests from the Court to:
1. Dismiss and reject the requests and submissions of the Republic of Costa Rica.
2. Determine, on the basis of international law, the complete course of the maritime
boundaries between all the maritime areas appertaining, respectively, to Nicaragua
and Costa Rica in the Pacific Ocean and in the Caribbean Sea:
- 20 -
(a) In the Pacific Ocean, the maritime boundary between the Republic of
Nicaragua and the Republic of Costa Rica starts at a point with co-ordinates
11° 03' 56.3" N, 85° 44' 28.3" W and follows geodetic lines connecting the
points with co-ordinates:
Points Latitude Longitude
P-1 11° 03' 57.6" N 85° 45' 27.0" W
P-2 11° 03' 57.8" N 85° 45' 36.8" W
P-3 11° 03' 47.6" N 85° 46' 34.0" W
P-4 11° 03' 54" N 85° 47' 13.2" W
P-5 11° 03' 25" N 85° 49' 42.4" W
P-6 11° 03' 17.7" N 85° 50' 06.3" W
P-7 11° 02' 44.8" N 85° 51' 25.2" W
P-8 (12 NM) 10° 54' 51.7" N 86° 10' 14.6" W
P-9 10° 50' 59.1" N 86° 21' 37.6" W
P-10 10° 41' 24.4" N 86° 38' 0.8" W
P-11 10° 19' 28.3" N 87° 11' 0.7" W
P-12 9° 53' 9.0" N 87° 47' 48.8" W
P-13
(200 NM) 9° 16' 27.5" N 88° 46' 10.9" W
(b) In the Caribbean Sea, the maritime boundary between the Republic of
Nicaragua and the Republic of Costa Rica starts at Point CA with co-ordinates
10° 56' 18.898" N, 83° 39' 52.536" W and follows geodetic lines connecting
the points with co-ordinates:
Points Latitude Longitude
C-1 10° 59' 21.3" N 83° 31' 6.9" W
C-1a (12 NM) 11° 00' 18.9" N 83° 27' 38.0" W
C-2 11° 01' 9.9" N 83° 24' 26.9" W
C-3 11° 05' 33.7" N 83° 03' 59.2" W
C-4 11° 11' 8.4" N 82° 34' 41.8" W
C-5 11° 05' 0.7" N 82° 18' 52.3" W
C-6 11° 05' 5.2" N 82° 14' 0.0" W
C-7 10° 49' 0.0" N 82° 14' 0.0" W
C-8 10° 49' 0.0" N 81° 26' 8.2" W
- 21 -
The maritime boundary between Point CA and the land is a geodetic line
connecting Point CA and the eastern headland of Harbor Head Lagoon (presently
located at [the] Court experts’ Point Ple).
(All co-ordinates are referred to WGS 84 datum.)”
*
42. In its Application filed in the case concerning the Northern Part of Isla Portillos,
Costa Rica made the following requests:
“Accordingly, the Court is asked:
(a) To determine the precise location of the land boundary separating both ends of the
Los Portillos/Harbor Head Lagoon sandbar from Isla Portillos, and in doing so to
determine that the only Nicaraguan territory existing today in the area of
Isla Portillos is limited to the enclave consisting of Los Portillos/Harbor Head
Lagoon and the sandbar separating the Lagoon from the Caribbean Sea, insofar as
this sandbar remains above water at all times and thus this enclave is capable of
constituting territory appertaining to a State. Consequently, that the land boundary
runs today from the northeastern corner of the Lagoon by the shortest line to the
Caribbean Sea and from the northwestern corner of the Lagoon by the shortest line
to the Caribbean Sea.
(b) To adjudge and declare that, by establishing and maintaining a new military camp
on the beach of Isla Portillos, Nicaragua has violated the sovereignty and territorial
integrity of Costa Rica, and is in breach of the Judgment of the Court of
16 December 2015 in the Certain Activities case. Consequently, Costa Rica further
requests the Court to declare that Nicaragua must withdraw its military camp
situated in Costa Rican territory and fully comply with the Court’s 2015 Judgment.
Costa Rica reserves it[s] rights to seek any further remedies with respect to any
damage that Nicaragua has or may cause to its territory.”
43. In the course of the written proceedings in the case concerning the Northern Part of
Isla Portillos, the following submissions were presented by the Parties:
On behalf of the Government of Costa Rica,
in the Memorial:
“Costa Rica respectfully requests the Court:
(a) To determine the precise location of the land boundary separating both ends of the
Los Portillos/Harbor Head Lagoon sandbar from Isla Portillos, and in doing so to
determine that the only Nicaraguan territory existing today in the area of
- 22 -
Isla Portillos is limited to the enclave consisting of Los Portillos/Harbor Head
Lagoon and the sandbar separating the Lagoon from the Caribbean Sea, insofar as
this sandbar remains above water at all times and thus this enclave is capable of
constituting territory appertaining to a State. Consequently, that the land boundary
runs today from the northeastern corner of the Lagoon by the shortest line to the
Caribbean Sea and from the northwestern corner of the Lagoon by the shortest line
to the Caribbean Sea.
(b) To adjudge and declare that, by establishing and maintaining a new military camp
on the beach of Isla Portillos, Nicaragua has violated the sovereignty and territorial
integrity of Costa Rica, and is in breach of the Judgment of the Court of
16 December 2015 in the Certain Activities case. Consequently, Costa Rica further
requests the Court to declare that Nicaragua must withdraw its military camp
situated in Costa Rican territory and fully comply with the Court’s 2015 Judgment.
Costa Rica reserves it[s] rights to seek any further remedies with respect to any
damage that Nicaragua has or may cause to its territory.”
On behalf of the Government of Nicaragua,
in the Counter-Memorial:
“For the reasons exposed in the present Counter-Memorial, the Republic of
Nicaragua respectfully requests the Court to adjudge and declare that:
1. the stretch of coast abutting the Caribbean Sea which lies between the
Harbor Head Lagoon and the mouth of the San Juan River constitutes Nicaraguan
territory;
2. the military camp set up by Nicaragua is located on Nicaraguan territory and
consequently;
3. the requests and submissions of the Republic of Costa Rica are rejected in their
entirety.”
44. At the oral proceedings in the joined cases, the following submissions were presented by
the Parties with respect to the case concerning the Northern Part of Isla Portillos:
On behalf of the Government of Costa Rica,
at the hearing of 10 July 2017:
“Costa Rica respectfully requests the Court:
1. (a) to adjudge and declare that Nicaragua’s submission that the stretch of coast
abutting the Caribbean Sea which lies between the Harbor Head Lagoon and
the mouth of the San Juan River constitutes Nicaraguan territory is
inadmissible, on the basis that the issue has already been settled by the
Judgment of the Court dated 16 December 2015 in the Certain Activities case;
- 23 -
(b) to reject all other submissions made by Nicaragua;
2. (a) to determine the precise location of the land boundary separating both ends of
the Los Portillos/Harbor Head Lagoon sandbar from Isla Portillos, and in
doing so to determine that the only Nicaraguan territory existing today in the
area of Isla Portillos is limited to the enclave consisting of
Los Portillos/Harbor Head Lagoon and the sandbar separating the lagoon from
the Caribbean Sea, insofar as this sandbar remains above water at all times and
thus this enclave is capable of constituting territory appertaining to a State.
Consequently, that the land boundary runs today from the northeastern corner
of the lagoon by the shortest line to the Caribbean Sea and from the
northwestern corner of the lagoon by the shortest line to the Caribbean Sea;
(b) to adjudge and declare that, by establishing and maintaining a new military
camp on the beach of Isla Portillos, Nicaragua has violated the sovereignty
and territorial integrity of Costa Rica, and is in breach of the Judgment of the
Court of 16 December 2015 in the Certain Activities case. Consequently,
Costa Rica further requests the Court to declare that Nicaragua must withdraw
its military camp situated in Costa Rican territory and fully comply with the
Court’s 2015 Judgment.”
On behalf of the Government of Nicaragua,
at the hearing of 13 July 2017:
“Nicaragua respectfully requests from the Court to:
Adjudge and declare that:
(a) the stretch of coast abutting the Caribbean Sea which lies between the
Harbor Head Lagoon and the mouth of the San Juan River constitutes Nicaraguan
territory;
(b) the military camp set up by Nicaragua is located on Nicaraguan territory and
consequently;
(c) the requests and submissions of the Republic of Costa Rica are rejected in their
entirety.”
*
* *
- 24 -
I. JURISDICTION OF THE COURT
45. In both of the cases under consideration, Costa Rica invokes, as bases of jurisdiction, the
declarations by which Costa Rica and Nicaragua have recognized the compulsory jurisdiction of
the Court under paragraphs 2 and 5, respectively, of Article 36 of the Statute, as well as
Article XXXI of the Pact of Bogotá (see paragraphs 2 and 22 above). Nicaragua does not contest
the Court’s jurisdiction to entertain Costa Rica’s claims.
46. The Court finds that it has jurisdiction over the disputes in the joined cases.
II. GENERAL BACKGROUND
A. Geography
47. Costa Rica and Nicaragua are situated in Central America, sharing a land boundary that
spans the Central American isthmus from the Caribbean Sea to the Pacific Ocean. Nicaragua lies to
the north of that boundary and Costa Rica to the south. Nicaragua has a border with Honduras in
the north, while Costa Rica shares a border with Panama in the south.
48. Isla Portillos, the northern part of which is the subject of the land boundary dispute, is an
area (approximately 17 sq km) bounded to the west by the San Juan River and to the north by the
Caribbean Sea. At the north-western extremity of Isla Portillos, a sandspit of variable length
deflects the final course of the San Juan River, displacing its mouth towards the west. On the coast
of Isla Portillos, approximately 3.6 km east of the mouth of the San Juan River, is a lagoon called
Laguna Los Portillos by Costa Rica and Harbor Head Lagoon by Nicaragua. This lagoon is at
present separated from the Caribbean Sea by a sandbar.
49. The Caribbean Sea lies in the western part of the Atlantic Ocean. It is partially enclosed
to the north and east by the Caribbean islands, and bounded to the south and west by South and
Central America, respectively. In the Caribbean Sea off the coast of Nicaragua there are several
islands and cays, the most prominent of which are the Corn Islands, located approximately
26 nautical miles off its coast, and having an area, respectively, of 9.6 sq km (Great Corn Island)
and 3 sq km (Little Corn Island). The Corn Islands have a population of approximately
7,400 inhabitants. Other small features lying off the Nicaraguan coast include Paxaro Bovo, the
Palmenta Cays, Cayos de Perlas, Tyra Rock, Man of War Cays, Ned Thomas Cay, Miskitos Cays,
Muerto Cay and Edinburgh Reef. Costa Rica has two small islands, Isla Pájaros and Isla Uvita, less
than half a nautical mile off its coast near the city of Limón.
50. On the Pacific side, the coast of Nicaragua is relatively straight and generally follows a
north-west to south-east direction. The Costa Rican coast is more sinuous and includes the
peninsulas of Santa Elena (near the land boundary terminus), Nicoya and Osa.
- 25 -
B. Historical context
51. As the Court noted in its Judgment of 16 December 2015 in the case concerning Certain
Activities Carried Out by Nicaragua in the Border Area (Costa Rica v. Nicaragua) (I.C.J. Reports
2015 (II), p. 665, hereinafter the “2015 Judgment” in the “Certain Activities case”), the present
disputes between the Parties are set within a historical context dating back to the 1850s. Following
hostilities between the two States in 1857, the Governments of Costa Rica and Nicaragua signed,
on 15 April 1858, a Treaty of Limits, which was ratified by Costa Rica on 16 April 1858 and by
Nicaragua on 26 April 1858 (Consolidated Treaty Series, Vol. 118, p. 439, hereinafter the
“1858 Treaty”). The 1858 Treaty fixed the course of the land boundary between Costa Rica and
Nicaragua from the Pacific Ocean to the Caribbean Sea. According to Article II of the Treaty, part
of the boundary between the two States runs along the right (Costa Rican) bank of the San Juan
River from a point three English miles below Castillo Viejo, a small town in Nicaragua, to “the end
of Punta de Castilla, at the mouth of the San Juan” on the Caribbean coast.
52. Following challenges by Nicaragua on various occasions to the validity of the
1858 Treaty, Costa Rica and Nicaragua signed another instrument on 24 December 1886, whereby
the two States agreed to submit the question of the validity of the 1858 Treaty to the President of
the United States of America, Grover Cleveland, for arbitration. In addition, the Parties agreed that,
if the 1858 Treaty were found to be valid, President Cleveland should also decide “upon all the
other points of doubtful interpretation which either of the parties may find in the treaty”. On
22 June 1887, Nicaragua communicated to Costa Rica 11 points of doubtful interpretation, which
were subsequently submitted to President Cleveland for resolution. The Cleveland Award of 1888
confirmed, in its paragraph 1, the validity of the 1858 Treaty and found, in its paragraph 3 (1), that
the boundary line between the two States on the Atlantic side “begins at the extremity of Punta de
Castilla at the mouth of the San Juan de Nicaragua River, as they both existed on the 15th day of
April 1858”.
53. Subsequent to the Cleveland Award, the Parties agreed in the “Convention on border
demarcation concluded between the Republic of Costa Rica and the Republic of Nicaragua”, signed
at San Salvador on 27 March 1896 (United Nations, Reports of International Arbitral Awards
(RIAA), Vol. XXVIII, p. 211), to establish two national Demarcation Commissions, each composed
of two members (Art. I). This Convention further provided that the Commissions would include an
engineer, appointed by the President of the United States of America, who “shall have broad
powers to decide whatever kind of differences may arise in the course of any operations and
[whose] ruling shall be final” (Art. II). United States General Edward Porter Alexander was so
appointed. During the demarcation process, which began in 1897 and was concluded in 1900,
General Alexander rendered five Awards (ibid., pp. 215 and following for the first four Awards).
54. In his First Award, dated 30 September 1897, General Alexander determined the starting
segment of the land boundary near the Caribbean Sea in light of geomorphological changes that
had occurred since 1858. That segment was defined as starting from “the northwestern extremity of
what seems to be the solid land, on the east side of Harbor Head Lagoon” and then running “across
the bank of sand, from the Caribbean Sea into the waters of Harbor Head Lagoon”. From there,
Alexander determined that the boundary would “follow the water’s edge around the harbor until it
reaches the river proper by the first channel met. Up this channel, and up the river proper, the line
shall continue to ascend as directed in the treaty.” (Ibid., p. 220). As the Court noted in the 2015
Judgment, “what the Arbitrator considered to be the ‘first channel’ was the branch of the
- 26 -
Lower San Juan River which was then flowing into the Harbor Head Lagoon” (I.C.J. Reports
2015 (II), p. 699, para. 73). Following Alexander’s First Award, the Demarcation Commissions
recorded the co-ordinates of the starting-point of the land boundary determined by General
Alexander by reference to the centre of Plaza Victoria in old San Juan de Nicaragua (Greytown)
and other points on the ground.
55. Since the time of the Alexander Awards and the work of the Demarcation Commissions,
the northern part of Isla Portillos has continued to undergo significant geomorphological changes.
In 2010, a dispute arose between Costa Rica and Nicaragua with regard to certain activities carried
out by Nicaragua in that area. In its 2015 Judgment, the Court considered the impact of some of
these changes on the issue of territorial sovereignty. The Court stated “that the territory under
Costa Rica’s sovereignty extends to the right bank of the Lower San Juan River as far as its mouth
in the Caribbean Sea” (I.C.J. Reports 2015 (II), p. 703, para. 92). The Court thus concluded that
Costa Rica had sovereignty over a 3 sq km area in the northern part of Isla Portillos, although
noting in its description of this area that it did “not specifically refer to the stretch of coast abutting
the Caribbean Sea which lies between the Harbor Head Lagoon, which lagoon both Parties agree is
Nicaraguan, and the mouth of the San Juan River” (I.C.J. Reports 2015 (II), pp. 696-697,
paras. 69-70; p. 740, para. 229 (1)). The course of the land boundary on this stretch of coast is one
of the subjects of dispute between the Parties in the present joined cases.
56. With respect to maritime areas, a bilateral Sub-Commission on Limits and Cartography
was established by the two Parties in May 1997 to carry out preliminary technical studies regarding
possible maritime delimitations in the Pacific Ocean and the Caribbean Sea. In 2002, the
Vice-Ministers for Foreign Affairs of both countries instructed the bilateral Sub-Commission to
begin negotiations. The Sub-Commission held five meetings between 2002 and 2005. Several
technical meetings were also held between the Costa Rican National Geographic Institute and the
Nicaraguan Institute for Territorial Studies during the same period. Following these initial
meetings, negotiations on maritime delimitations between the two States stalled.
C. Delimitations already effected in the Caribbean Sea
and the Pacific Ocean
57. In the Caribbean Sea, Costa Rica concluded, on 2 February 1980, a treaty with Panama
delimiting a maritime boundary; this treaty entered into force on 11 February 1982. Costa Rica
negotiated and signed a maritime delimitation treaty with Colombia in 1977, but never ratified that
instrument. Nicaragua’s maritime boundaries with Honduras (to the north) and Colombia (to the
east) have been established by Judgments of the Court in 2007 and 2012, respectively (Territorial
and Maritime Dispute between Nicaragua and Honduras in the Caribbean Sea (Nicaragua v.
Honduras), Judgment, I.C.J. Reports 2007 (II), p. 659; Territorial and Maritime Dispute
(Nicaragua v. Colombia), Judgment, I.C.J. Reports 2012 (II), p. 624). Colombia and Panama also
concluded a maritime delimitation treaty establishing their boundary in the Caribbean Sea on
20 November 1976; this treaty entered into force on 30 November 1977 (United Nations, Treaty
Series (UNTS), Vol. 1074, p. 221).
58. The above-mentioned treaty concluded by Costa Rica and Panama in 1980 also delimited
their maritime boundary in the Pacific Ocean. For its part, Nicaragua has not concluded any treaty
establishing a maritime boundary in the Pacific Ocean.
- 27 -
- 28 -
III. LAND BOUNDARY IN THE NORTHERN PART
OF ISLA PORTILLOS
A. Issues concerning territorial sovereignty
59. The case concerning the Land Boundary in the Northern Part of Isla Portillos raises
issues of territorial sovereignty which it is expedient to examine first, because of their possible
implications for the maritime delimitation in the Caribbean Sea. The Parties express divergent
views on the interpretation of the 2015 Judgment and advance opposing claims on certain questions
relating to sovereignty over the coast of the northern part of Isla Portillos.
60. In the operative part of the 2015 Judgment, the Court stated that “Costa Rica has
sovereignty over the ‘disputed territory’, as defined by the Court in paragraphs 69-70 of the . . .
Judgment”. These paragraphs read as follows:
“69. Since it is uncontested that Nicaragua conducted certain activities in the
disputed territory, it is necessary, in order to establish whether there was a breach of
Costa Rica’s territorial sovereignty, to determine which State has sovereignty over that
territory. The ‘disputed territory’ was defined by the Court in its Order of 8 March
2011 on provisional measures as ‘the northern part of Isla Portillos, that is to say, the
area of wetland of some 3 square kilometres between the right bank of the disputed
caño, the right bank of the San Juan River up to its mouth at the Caribbean Sea and
the Harbor Head Lagoon’ (I.C.J. Reports 2011 (I), p. 19, para. 55). The caño referred
to is the one which was dredged by Nicaragua in 2010. Nicaragua did not contest this
definition of the ‘disputed territory’, while Costa Rica expressly endorsed it in its final
submissions (para. 2 (a)). The Court will maintain the definition of ‘disputed territory’
given in the 2011 Order. It recalls that its Order of 22 November 2013 indicating
provisional measures specified that a Nicaraguan military encampment ‘located on the
beach and close to the line of vegetation’ near one of the caños dredged in 2013 was
‘situated in the disputed territory as defined by the Court in its Order of 8 March 2011’
(I.C.J. Reports 2013, p. 365, para. 46).
70. The above definition of the ‘disputed territory’ does not specifically refer to
the stretch of coast abutting the Caribbean Sea which lies between the Harbor Head
Lagoon, which lagoon both Parties agree is Nicaraguan, and the mouth of the San Juan
River. In their oral arguments the Parties expressed different views on this issue.
However, they did not address the question of the precise location of the mouth of the
river nor did they provide detailed information concerning the coast. Neither Party
requested the Court to define the boundary more precisely with regard to this coast.
Accordingly, the Court will refrain from doing so.” (Judgment, I.C.J.
Reports 2015 (II), pp. 696-697.)
- 29 -
61. According to Costa Rica’s reading of that Judgment, “the beach of Isla Portillos belongs
to Costa Rica. This decision possesses the force of res judicata, as reflected in Articles 59 and 60
of the Court’s Statute.” Therefore, “[o]nly the precise location of the boundary at each end of the
sandbar of Harbor Head Lagoon remains open.” Costa Rica maintains that the purpose behind the
first sentence of paragraph 70 of the 2015 Judgment was to leave open the question whether there
was a maritime feature beyond the beach of Isla Portillos, and not to exclude that beach from the
disputed territory. According to Costa Rica, “the beach of Isla Portillos was expressly included
within the disputed territory” and was thus declared to be Costa Rican territory.
62. In Costa Rica’s view, the mainland boundary runs, consistent with Article II of the
1858 Treaty, along the right bank of the Lower San Juan River all the way to its mouth in the
Caribbean Sea and the land boundary terminus is located on the right bank of the San Juan River at
its mouth. According to Costa Rica, the only Nicaraguan territory in the area of Isla Portillos is the
enclave of Los Portillos/Harbor Head Lagoon and the sandbar separating the Lagoon from the
Caribbean Sea, “for so long as it is territory capable of appertaining to a State”.
63. Nicaragua argues that, in its 2015 Judgment, “the Court did not . . . determine the precise
location of the boundary at any point between the northwestern end of Harbor Head Lagoon and
the mouth of the San Juan River” (emphasis in the original). Nicaragua maintains that the Court in
that Judgment refrained from defining the boundary with regard to the coast between the mouth of
the San Juan River and Harbor Head Lagoon and “did not fix the limits of the ‘territory in
dispute’”. Nicaragua contends that the Certain Activities case was one regarding State
responsibility for wrongful acts and was not concerned with delimitation. According to Nicaragua,
that case did not require the Court to take a position regarding sovereignty over the relevant stretch
of coast or its precise limits. Therefore, in Nicaragua’s view, sovereignty over the beach of
Isla Portillos remains to be determined.
64. In this respect, Nicaragua argues that the 1858 Treaty and the subsequent Cleveland and
Alexander Awards indicate that the starting-point of the boundary is located at a fixed point at
Punta de Castilla, and not at the mouth of the San Juan River. It emphasizes that
President Cleveland fixed the starting-point of the land boundary “at the extremity of
Punta de Castilla at the mouth of the San Juan de Nicaragua River, as they both existed on the
15th day of April 1858” (emphasis added by Nicaragua). According to Nicaragua, the Cleveland
Award, which is still binding on the Parties, made clear that the starting-point was a “fixed
unmovable point” the location of which would not shift following changes in the flow of the River
(emphasis of Nicaragua). Nicaragua maintains that General Alexander’s First Award went “to great
lengths to find where Punta de Castilla was located, because that was the fixed starting point for the
border”.
65. In its Counter-Memorial, Nicaragua argued that the channel of the San Juan River which
flowed into Harbor Head Lagoon at the time of General Alexander’s First Award, and was
identified in the Award as marking the land boundary, still flows into the Lagoon. According to
Nicaragua, the beach of Isla Portillos and the sandbar between Harbor Head Lagoon and the
Caribbean Sea consist of the remnants of the barrier that used to separate the Lagoon from the
Caribbean Sea so that they should be considered an independent feature separated from the
mainland. In Nicaragua’s view, the land boundary between the Parties runs as follows:
- 30 -
“the land boundary starts at the north-east corner of the sandbar separating
Harbor Head Lagoon from the Caribbean Sea, cuts that sandbar and follows the
water’s edge around the lagoon until it meets the channel connecting Harbor Head
Lagoon to the lower San Juan. The boundary then follows the contour of Isla Portillos
up to the lower San Juan”.
Consequently, it submits that the stretch of coast between Harbor Head Lagoon and the mouth of
the San Juan River is under Nicaraguan sovereignty. Nicaragua argued in its oral pleadings that if
the Court were to accept Costa Rica’s position and decide that the coast is not under Nicaraguan
sovereignty, “the whole structure carefully created by the 1858 Treaty and the Awards would be
dismantled and the Nicaragua/Costa Rica border would have to be repeatedly under review”.
66. Nicaragua acknowledged at the hearings that the channel linking Harbor Head Lagoon to
the San Juan River had “partially disappeared” in recent years. It maintained that the “rules
governing the effects of accretion and erosion” do not apply to the present situation and that
accordingly “the boundary should continue to be defined by the approximate location of the former
channel, such that the boundary that now separates the beach from the wetland behind it
corresponds to the line of vegetation”.
67. In its final submissions, Costa Rica specifically requests the Court
“to adjudge and declare that Nicaragua’s submission that the stretch of coast abutting
the Caribbean Sea which lies between Harbor Head Lagoon and the mouth of the
San Juan River constitutes Nicaraguan territory is inadmissible, on the basis that the
issue has already been settled by the Judgment of the Court dated 16 December 2015
in the Certain Activities case”.
*
68. The Court has previously had the occasion to emphasize that “the principle of res
judicata, as reflected in Articles 59 and 60 of its Statute, is a general principle of law which
protects, at the same time, the judicial function of a court or tribunal and the parties to a case which
has led to a judgment that is final and without appeal” (Question of the Delimitation of the
Continental Shelf between Nicaragua and Colombia beyond 200 Nautical Miles from the
Nicaraguan Coast (Nicaragua v. Colombia), Preliminary Objections, Judgment, I.C.J.
Reports 2016, p. 125, para. 58 and authorities cited therein). However, for res judicata to apply in a
given case, the Court “must determine whether and to what extent the first claim has already been
definitively settled” (ibid., p. 126, para. 59), for “[i]f a matter has not in fact been determined,
expressly or by necessary implication, then no force of res judicata attaches to it” (ibid., para. 60,
quoting Application of the Convention on the Prevention and Punishment of the Crime of Genocide
(Bosnia and Herzegovina v. Serbia and Montenegro), Judgment, I.C.J. Reports 2007 (I), p. 95,
para. 126).
- 31 -
69. The Court recalls that the operative part of its 2015 Judgment stated that “Costa Rica has
sovereignty over the ‘disputed territory’, as defined . . . in paragraphs 69-70” of that Judgment
(I.C.J. Reports 2015 (II), p. 740, para. 229). The term “disputed territory” was described in those
paragraphs as including
“the northern part of Isla Portillos, that is to say, the area of wetland of some
3 square kilometres between the right bank of the disputed caño, the right bank of the
San Juan River up to its mouth at the Caribbean Sea and the Harbor Head Lagoon”
(ibid., p. 697, para. 69).
The Court noted, however, that
“[t]he above definition of the “disputed territory” does not specifically refer to the
stretch of coast abutting the Caribbean Sea which lies between the Harbor Head
Lagoon, which lagoon both Parties agree is Nicaraguan, and the mouth of the San Juan
River” (ibid., para. 70).
The Court further noted that the Parties
“did not address the question of the precise location of the mouth of the river nor did
they provide detailed information concerning the coast. Neither Party requested the
Court to define the boundary more precisely with regard to this coast. Accordingly,
the Court will refrain from doing so.” (Ibid.)
These passages indicate that no decision was taken by the Court in its 2015 Judgment on the
question of sovereignty concerning the coast of the northern part of Isla Portillos, since this
question had been expressly excluded. This means that it is not possible for the issue of sovereignty
over that part of the coast to be res judicata. Therefore, the Court cannot declare inadmissible
Nicaragua’s claim concerning sovereignty over that stretch of coast of Isla Portillos.
70. In its 2015 Judgment, the Court interpreted the 1858 Treaty as providing that “the
territory under Costa Rica’s sovereignty extends to the right bank of the Lower San Juan River as
far as its mouth in the Caribbean Sea” (I.C.J. Reports 2015 (II), p. 703, para. 92). However, the
absence of “detailed information”, which had been observed in the 2015 Judgment, had left the
geographical situation of the area in question somewhat unclear with regard to the configuration of
the coast of Isla Portillos, in particular regarding the existence of maritime features off the coast
and the presence of a channel separating the wetland from the coast.
71. The assessment made by the Court-appointed experts, which was not challenged by the
Parties, dispels all uncertainty about the present configuration of the coast and the existence of a
channel linking the San Juan River with Harbor Head Lagoon. The experts ascertained that “[o]ff
the coastline, there are no features above water even at low tide” and that, west of Harbor Head
Lagoon, “the coast is made up of a broad sandy beach with discontinuous and coast-parallel
enclosed lagoons in the backshore”, while “[i]n the westernmost portion, close to the mouth of the
San Juan River, there are no lagoons with free-standing water in the backshore”. Significantly, the
experts observed that there is no longer any water channel connecting the San Juan River with
Harbor Head Lagoon. Since there is no channel, there cannot be a boundary running along it.
Nicaragua’s contention that “the boundary should continue to be defined by the approximate
- 32 -
location of the former channel” linking the river with Harbor Head Lagoon ignores the fact that the
channel in question, as it existed at the time of the Alexander Awards, was running well north of
the present beach and has been submerged by the sea, as the Court-appointed experts noted,
explaining that “such . . . continuous channel has disappeared due to coastal recession”. In light of
these findings, the Court determines that Costa Rica has sovereignty over the whole of Isla Portillos
up to where the river reaches the Caribbean Sea. It follows from the 2015 Judgment and from the
foregoing that the starting-point of the land boundary is the point at which the right bank of the San
Juan River reaches the low-water mark of the coast of the Caribbean Sea. That point is currently
located at the end of the sandspit constituting the right bank of the San Juan River at its mouth.
72. However, as stated in the 2015 Judgment, the Parties agree that Nicaragua has
sovereignty over Harbor Head Lagoon (I.C.J. Reports 2015 (II), p. 697, para. 70). Costa Rica
requests the Court to
“determine the precise location of the land boundary separating both ends of the
Los Portillos/Harbor Head Lagoon sandbar from Isla Portillos, and in doing so to
determine that the only Nicaraguan territory existing today in the area of Isla Portillos
is limited to the enclave consisting of Los Portillos/Harbor Head Lagoon and the
sandbar separating the Lagoon from the Caribbean Sea, insofar as this sandbar
remains above water at all times and thus this enclave is capable of constituting
territory appertaining to a State”.
73. According to the Court-appointed experts, “Los Portillos/Harbor Head Lagoon is
commonly separated from the sea by [a] sand barrier”, although there may be “temporary channels
in the barrier”. This assessment, which implies that the barrier is above water even at high tide, was
not challenged by the Parties. The Court therefore considers that the Parties agree that both
Harbor Head Lagoon and the sandbar separating it from the Caribbean Sea are under Nicaragua’s
sovereignty. According to the experts, the sandbar extends between the points at the edge of the
north-eastern and north-western ends of the Lagoon. The current location of these points has been
identified by the experts in their report as points Ple2 and Plw2 with respective co-ordinates of
10° 55' 47.23522" N, 83° 40' 03.02241" W and 10° 56' 01.38471" N, 83° 40' 24.12588" W in
WGS 84 datum. The Court concludes that the sandbar extends between the points located at the
north-eastern and north-western ends of the Lagoon, currently between points Ple2 and Plw2,
respectively; from each of these two points, the land boundary should follow the shortest line
across the sandbar to reach the low-water mark of the coast of the Caribbean Sea (see sketch-map
No. 2 below).
- 33 -
- 34 -
B. Alleged violations of Costa Rica’s sovereignty
74. Costa Rica’s Application includes the claim that, “by establishing and maintaining a new
military camp on the beach of Isla Portillos, Nicaragua has violated the sovereignty and territorial
integrity of Costa Rica, and is in breach of the Judgment of the Court of 16 December 2015 in the
Certain Activities case”. Costa Rica was referring to a military camp that was placed in
August 2016 “to the northwest of the Lagoon’s sandbar and installed on the beach of the northern
part of Isla Portillos”. Costa Rica requests the Court to declare that “Nicaragua must withdraw its
military camp” and reserves its position with regard to further remedies.
75. Nicaragua initially asserted that the camp was situated on the “sandbar that separates
Harbor Head Lagoon from the Caribbean Sea”. Later in its pleadings, Nicaragua did not contest
that the camp was placed on the beach outside the limits of the sandbar separating the Lagoon from
the Caribbean Sea, but argued that “the whole coast belongs to Nicaragua”. In any case, Nicaragua
contends that the Court has not yet issued any decision with the effect of res judicata concerning
the beach where the camp was located.
76. As an alternative argument, Nicaragua maintains that, even if the Court were to find that
the entirety of the coast is under Costa Rican sovereignty, the camp was still positioned on a
portion of the beach that belongs to Nicaragua, because of the presence of a channel of water
running behind the camp and connecting to Harbor Head Lagoon.
*
77. The Court notes that the experts have assessed that the edge of the north-western end of
Harbor Head Lagoon lies east of the place where the military camp was located. The Court
observes that it is now common ground that the military camp was placed by Nicaragua on the
beach close to the sandbar, but not on it. The installation of the camp thus violated Costa Rica’s
territorial sovereignty as defined above. It follows that the camp must be removed from
Costa Rica’s territory. However, there was no breach by Nicaragua of the 2015 Judgment because,
as has been observed above (see paragraph 69), the boundary with regard to the coast had not been
defined in that Judgment.
78. The Court considers that the declaration of a violation of Costa Rica’s sovereignty and
the order addressed to Nicaragua to remove its camp from Costa Rica’s territory constitute
appropriate reparation.
IV.MARITIME DELIMITATION IN THE CARIBBEAN SEA
79. The Court has been requested to delimit the maritime boundaries between the Parties in
the Caribbean Sea and the Pacific Ocean. The Parties’ respective claims relating to the
Caribbean Sea are illustrated on sketch-map No. 3 below.
- 35 -
- 36 -
A. Starting-point of the maritime delimitation
80. The divergent views of the Parties concerning the starting-point of the land boundary are
reflected in their different approaches to defining the starting-point of the maritime delimitation in
the Caribbean Sea. According to Costa Rica, the maritime delimitation “must start at the mouth of
the San Juan River”. However, given the instability of the coast and in particular of the features
near the point where the San Juan River flows into the Caribbean Sea, Costa Rica suggests that the
starting-point of the maritime delimitation should be placed not at the western end of the sandspit at
the mouth of the river, but on “the solid ground at the base of the spit of Isla Portillos”. According
to Costa Rica, this point coincides with the point that the Court-appointed experts called point Pv
(see paragraph 104 below).
81. Nicaragua maintains that, according to the 1858 Treaty and the Cleveland Award, the
land boundary line “begins at the extremity of Punta de Castilla at the mouth of the San Juan de
Nicaragua River, as they both existed on the 15th day of April 1858” and that this point should be
used also for the maritime delimitation. Since General Alexander stated in his First Award that the
point in question could “not now be certainly located” and that
“it best fulfil[led] the demands of the treaty and of President Cleveland’s award to
adopt what is practically the headland of to-day, or the northwestern extremity of what
seems to be the solid land, on the east side of Harbor Head Lagoon” (RIAA,
Vol. XXVIII, p. 220),
Nicaragua argues that the point identified by General Alexander should be adopted as the
starting-point for the maritime delimitation even if it has been submerged by the sea.
82. In a communication to the Parties, the Court invited them to indicate in their oral
pleadings their positions concerning the possibility of “starting the maritime boundary from a fixed
point in the Caribbean Sea some distance from the coast”.
83. Costa Rica’s primary position remains that the Court should select a starting-point on
land. Costa Rica suggests as an alternative that the Court “connect any fixed point at sea [on the
equidistance line] to the mouth of the San Juan River with a mobile line segment”. This fixed point
would act as a “hinge point”. Costa Rica indicates that such a point, if adopted by the Court, should
be placed at a distance of 3 nautical miles from the coast, a distance sufficient to anticipate possible
physical changes.
84. While arguing for a different location of the starting-point, Nicaragua agrees that “the
‘hinge’ solution is practicable. The line connecting the fixed point at sea with the actual land
territory could be mobile, moving with natural changes in the coastline”. In its view, the fixed point
should be placed at the point that General Alexander identified as the starting-point of the land
boundary and should be joined to the north-eastern end of Harbor Head Lagoon by a mobile line.
85. The positions taken by the Parties with regard to the starting-point of the maritime
boundary are illustrated on sketch-map No. 4 below.
- 37 -
*
*
- 38 -
86. The Court observes that, since the starting-point of the land boundary is currently located
at the end of the sandspit bordering the San Juan River where the river reaches the Caribbean Sea
(see paragraph 71 above), the same point would normally be the starting-point of the maritime
delimitation. However, the great instability of the coastline in the area of the mouth of the San Juan
River, as indicated by the Court-appointed experts, prevents the identification on the sandspit of a
fixed point that would be suitable as the starting-point of the maritime delimitation. It is preferable
to select a fixed point at sea and connect it to the starting-point on the coast by a mobile line.
Taking into account the fact that the prevailing phenomenon characterizing the coastline at the
mouth of the San Juan River is recession through erosion from the sea, the Court deems it
appropriate to place a fixed point at sea at a distance of 2 nautical miles from the coast on the
median line.
* *
87. With regard to the enclave under Nicaragua’s sovereignty, Costa Rica argues that no
starting-point for the maritime delimitation can be placed on the sandbar separating Harbor Head
Lagoon from the Caribbean Sea because of the general characteristics of the sandbar and in
particular its instability.
88. Nicaragua addresses the issue of the starting-points of maritime delimitation relating to
the enclave only as an alternative, in the event that the Court does not accept Nicaragua’s main
contention that the starting-point of the maritime delimitation is the same point identified by
General Alexander as the starting-point for the land boundary. Nicaragua notes that, should its
contention not be accepted by the Court, “there would be three land boundary termini on the
Caribbean Sea defining different stretches of coasts belonging to one Party or the other, generating
overlapping projections into the sea”.
*
89. The Court notes that the sandbar separating Harbor Head Lagoon from the Caribbean Sea
is a minor feature without vegetation and characterized by instability. In relation to this sandbar,
the question of the starting-points of the maritime delimitation is bound up with the effects, if any,
of this feature on the maritime delimitation. This latter issue will be addressed below, taking into
account the characteristics of the feature in question.
B. Delimitation of the territorial sea
90. With regard to the delimitation of the territorial sea, Article 15 of UNCLOS, which is
applicable between the Parties, both of them being party to the Convention, reads as follows:
- 39 -
“Where the coasts of two States are opposite or adjacent to each other, neither
of the two States is entitled, failing agreement between them to the contrary, to extend
its territorial sea beyond the median line every point of which is equidistant from the
nearest points on the baselines from which the breadth of the territorial seas of each of
the two States is measured. The above provision does not apply, however, where it is
necessary by reason of historic title or other special circumstances to delimit the
territorial seas of the two States in a way which is at variance therewith.”
The Court will use the term “median line” as in the above provision but will refer to “equidistance
line” when it summarizes pleadings of the Parties where the latter term is used.
*
91. Costa Rica argues that the Court should delimit the Parties’ boundary in the territorial sea
first, and thereafter in the exclusive economic zone and on the continental shelf, by means of two
different methods. According to Costa Rica, the Court has consistently differentiated between the
delimitation of the territorial sea under Article 15 of UNCLOS, and the delimitation of the
exclusive economic zone and of the continental shelf under Articles 74 and 83 of UNCLOS,
according to which it “shall be effected by agreement on the basis of international law, as referred
to in Article 38 of the Statute of the International Court of Justice, in order to achieve an equitable
solution”.
92. Nicaragua argues that Article 15 of UNCLOS does not stipulate how the delimitation is
to be effected, but only how States must act failing an agreement on delimitation. According to
Nicaragua, a flexible application of the equidistance/special circumstances rule is necessary in
order to “take into account local characteristics of the configuration of the coastline”. Nicaragua
further argues that there is no practical difference between the régime of delimitation of the
territorial sea according to Article 15 of UNCLOS and the régime applicable to the delimitation of
the exclusive economic zone and the continental shelf, respectively outlined in Articles 74 and 83
of UNCLOS. In its view, “the approaches to delimitation of the different maritime zones are
convergent” and all relevant provisions of UNCLOS must be read together and in context.
93. Costa Rica maintains that in the delimitation of the territorial sea Nicaragua has taken
into account legal concepts and geographic features that could only be relevant to the delimitation
of its exclusive economic zone and continental shelf. Costa Rica indicates that, while the provisions
of UNCLOS may not be taken in isolation, Article 15 “does not refer to or incorporate Articles 74
and 83, and vice versa”: Article 15 uses different terms, concerns a different subject-matter and
consists of an autonomous provision. Costa Rica recalls that, in earlier cases concerning the
delimitation of the territorial sea, the Court recognized the primacy of equidistance and decided
that it would depart from an equidistance line only if special circumstances justified such a
departure. While Costa Rica agrees that there is an element of flexibility in the adjustment of the
line based on the existence of special circumstances, it maintains that this flexibility could not
override the plain meaning of the text of UNCLOS which distinguishes between delimitation
methods in different maritime zones.
- 40 -
94. However, the Parties agree that, for the delimitation of the territorial sea, it is first
necessary to establish the equidistance line. The Parties proceeded to discuss the delimitation of the
territorial sea on the basis of the same method. They began by drawing a provisional equidistance
line, and subsequently argued whether special circumstances existed that would justify the
adjustment of the line.
95. Costa Rica recalls that base points must be selected on coastal features that represent the
“physical reality at the time of the delimitation” (referring to Maritime Delimitation in the Black
Sea (Romania v. Ukraine), Judgment, I.C.J. Reports 2009, p. 106, para. 131). Consequently, base
points should not be placed on “ephemeral, sandy, unstable features”. According to Costa Rica,
those features include Barra Morris Creek, a sandbar on the left bank of the mouth of the San Juan
River, and the sandspit north-west of Isla Portillos.
96. Nicaragua identifies base points on dry land “and not . . . any points that lie upon straight
baselines but not upon land”. Nicaragua criticizes the fact that, in the construction of the
equidistance line in the territorial sea, Costa Rica did not place base points on Paxaro Bovo and
Palmenta Cays. According to Nicaragua, these features are entitled to a territorial sea and cannot be
disregarded in the drawing of the equidistance line in the territorial sea.
97. Objecting to Nicaragua’s view that base points should be placed on Paxaro Bovo and
Palmenta Cays for the construction of the equidistance line in the territorial sea, Costa Rica argues
that, in light of their location, those features can have no impact on the course of the delimitation
line in the territorial sea.
*
98. In accordance with its established jurisprudence, the Court will proceed in two stages:
first, the Court will draw a provisional median line; second, it will consider whether any special
circumstances exist which justify adjusting such a line (Maritime Delimitation and Territorial
Questions between Qatar and Bahrain (Qatar v. Bahrain), Merits, Judgment, I.C.J. Reports 2001,
p. 94, para. 176; Territorial and Maritime Dispute between Nicaragua and Honduras in the
Caribbean Sea (Nicaragua v. Honduras), Judgment, I.C.J. Reports 2007 (II), p. 740, para. 268).
99. The Court notes that Nicaragua has adopted a system of straight baselines in the
Caribbean Sea by Decree No. 33-2013 of 19 August 2013, which Costa Rica has challenged.
However, Nicaragua does not rely on those baselines for determining the equidistance lines
concerning the territorial sea, the exclusive economic zone and the continental shelf.
100. The Court will construct the provisional median line for delimiting the territorial sea
only on the basis of points situated on the natural coast, which may include points placed on islands
or rocks. The base points used by the Court are located on salient points that are situated on solid
- 41 -
land and thus have a relatively higher stability than points placed on sandy features. The placement
of these base points is illustrated on sketch-map No. 5 below. The Court observes that Paxaro Bovo
and Palmenta Cays do not affect the construction of the median line in the territorial sea.
* *
101. Nicaragua contends that the equidistance line in the territorial sea should be adjusted in
view of a “special circumstance” consisting in “the exaggerated cut-off resulting from the change
from a convex to a concave coastline in the immediate vicinity of the Punta de Castilla startingpoint”.
Nicaragua maintains that this portion of the coast does not reflect its general direction and
notes that the resulting deviation “persists for a significant part of the length of the equidistance
line”. It argues that the convex-concave combination has to be regarded as a special circumstance
requiring an adjustment of the strict equidistance line in the territorial sea. According to Nicaragua,
it is “common ground that cut-offs resulting from coastal configurations” may lead to necessary
adjustments of the provisional equidistance line.
102. Costa Rica argues that there are no “special circumstances which require a delimitation
of the territorial sea other than on the basis of equidistance”. In response to Nicaragua’s argument,
Costa Rica contends that recourse to the equidistance line would not create any inequitable cut-off
within the territorial sea. It maintains that Nicaragua’s argument is based on an “artificially
expanded geographic scope for the territorial sea delimitation” and inaccurate depictions of the
coastal projections that it alleges would be cut off. According to Costa Rica, the boundary in the
territorial sea should therefore follow an unadjusted equidistance line.
*
103. The Court considers that, for the delimitation of the territorial sea, the combined effect
of the concavity of Nicaragua’s coast west of the mouth of the San Juan River and of the convexity
of Costa Rica’s coast east of Harbor Head Lagoon is of limited significance and does not represent
a special circumstance that could justify an adjustment of the median line under Article 15 of
UNCLOS.
104. However, the Court considers that a special circumstance affecting maritime
delimitation in the territorial sea consists in the high instability and narrowness of the sandspit near
the mouth of the San Juan River which constitutes a barrier between the Caribbean Sea and a
sizeable territory appertaining to Nicaragua (see paragraph 86 above). The instability of this
sandspit does not allow one to select a base point on that part of Costa Rica’s territory, as
Costa Rica acknowledges, or to connect a point on the sandspit to the fixed point at sea for the first
part of the delimitation line. The Court is of the view that it is more appropriate that the fixed point
at sea on the median line, referred to in paragraph 86 above, be connected by a mobile line to the
- 42 -
point on solid land on Costa Rica’s coast which is closest to the mouth of the river. Under the
present circumstances, this point has been identified by the Court-appointed experts as point Pv,
with co-ordinates 10° 56' 22.56"N, 83° 41' 51.81"W (WGS 84 datum), but there may be
geomorphological changes over time. For the present, the delimitation line in the territorial sea thus
extends from the fixed point at sea landwards to the point on the low-water mark of the coast of the
Caribbean Sea that is closest to point Pv. From the fixed point seawards, the delimitation line in the
territorial sea is the median line as determined by the base points selected in relation to the present
situation of the coast.
105. The Court considers that another special circumstance is relevant for the delimitation of
the territorial sea. The instability of the sandbar separating Harbor Head Lagoon from the
Caribbean Sea and its situation as a small enclave within Costa Rica’s territory call for a special
solution. Should territorial waters be attributed to the enclave, they would be of little use to
Nicaragua, while breaking the continuity of Costa Rica’s territorial sea. Under these circumstances,
the delimitation in the territorial sea between the Parties will not take into account any entitlement
which might result from the enclave.
106. The delimitation line in the territorial sea is obtained by joining landwards the fixed
point at sea defined below with the point on solid land on Costa Rica’s coast that is closest to the
mouth of the river (see paragraph 104 above) and by joining seawards with geodetic lines the
points with the following co-ordinates in WGS 84 datum:
Turning point Latitude north Longitude west
Fixed point at 2 NM (FP) 10° 58' 22.9" 83° 41' 39.8"
A 11° 01' 38.6" 83° 40' 50.4"
B 11° 02' 32.0" 83° 40' 12.9"
C 11° 02' 42.7" 83° 40' 05.6"
D 11° 02' 45.7" 83° 40' 03.7"
E 11° 03' 14.3" 83° 39' 45.6"
F 11° 04' 10.9" 83° 39' 07.7"
G 11° 04' 54.2" 83° 38' 35.3"
H 11° 05' 02.7" 83° 38' 28.7"
I 11° 06' 04.1" 83° 37' 42.6"
J 11° 06' 24.8" 83° 37' 26.3"
K 11° 06' 46.7" 83° 37' 08.0"
L 11° 07' 24.0" 83° 36' 34.7"
The boundary in the territorial sea shall terminate at point Lx (with current co-ordinates
11° 07' 28.8" N and 83° 36' 30.4" W), at the intersection of the 12-nautical-mile line with the
geodetic line connecting point L with the first turning point on the provisional equidistance line in
the exclusive economic zone, identified as point 1 and having the co-ordinates indicated at
paragraph 145 below. The delimitation line is illustrated on sketch-map No. 5 below.
- 43 -
- 44 -
C. Delimitation of the exclusive economic zone and the continental shelf
107. The Court will now proceed to the delimitation of the exclusive economic zones and
continental shelves appertaining to Costa Rica and Nicaragua, for which both Parties requested the
Court to draw a single delimitation line. The relevant provisions of UNCLOS read as follows:
Article 74
“1. The delimitation of the exclusive economic zone between States with
opposite or adjacent coasts shall be effected by agreement on the basis of international
law, as referred to in Article 38 of the Statute of the International Court of Justice, in
order to achieve an equitable solution.”
Article 83
“1. The delimitation of the continental shelf between States with opposite or
adjacent coasts shall be effected by agreement on the basis of international law, as
referred to in Article 38 of the Statute of the International Court of Justice, in order to
achieve an equitable solution.”
(a) Relevant coasts and relevant area
(i) Relevant coasts
108. An essential step in maritime delimitation is identifying the relevant coasts: those that
“generate projections which overlap with projections from the coast of the other Party” (Maritime
Delimitation in the Black Sea (Romania v. Ukraine), Judgment, I.C.J. Reports 2009, p. 97,
para. 99). For defining the criteria applicable to determining when relevant overlapping projections
exist, both Parties refer to the Court’s jurisprudence and to a passage in the arbitral award in Bay of
Bengal Maritime Boundary Arbitration (Bangladesh v. India), in which the arbitral tribunal noted
that “there is a margin of appreciation in determining the projections generated by a segment of
coastline and a point at which a line drawn at an acute angle to the general direction of the coast
can no longer be fairly said to represent the seaward projection of that coast” (Tribunal established
under Annex VII of UNCLOS, Award of 7 July 2014, International Law Reports, Vol. 167, p. 86,
para. 302).
109. However, Nicaragua and Costa Rica take different approaches to the determination of
the relevant coasts in the present proceedings. Nicaragua argues that a segment of coast may be
considered relevant only if its frontal projection “overlaps with the seaward projection of the coast
of [the] other Party”, the term “seaward” having “the connotation of ‘in the direction of the sea’”.
Costa Rica contends that, with some exceptions concerning particular situations  such as the case
of a coast that “faces entirely away from the area of overlapping potential entitlements”  the
relevant coasts are determined by establishing which coasts generate overlapping entitlements by
employing radial projections, using an envelope of arcs.
110. Notwithstanding this divergence of methods, the Parties reach nearly identical solutions
with regard to the relevant coasts on the Caribbean Sea. According to Nicaragua, “its relevant coast
includes the coast up to Coconut Point”, while the entire coast of Costa Rica is relevant (see
sketch-map No. 7 below). Costa Rica takes the same position with regard to its own coast but
considers that “only the coast of Nicaragua ending at or near Punta de Perlas is relevant on the
Nicaraguan coast” (see sketch-map No. 6 below).
- 45 -
- 46 -
*
- 47 -
111. The Court considers that the entire mainland coast of Costa Rica is relevant. In the
Court’s view, the mainland coast of Nicaragua is relevant up to Punta Gorda (north), where the
coast shows a significant inflexion. All these coasts generate projections that overlap with
projections from the other Party’s coast.
112. One divergence between the Parties regarding the relevant coasts concerns Nicaragua’s
contention that a few kilometres should be added to the overall length of its relevant coast because
some parts of the coasts of the Corn Islands and of the Cayos de Perlas should also be included.
The Court observes that the Corn Islands, but not the Cayos de Perlas, were already considered in
the Judgment in the case between Nicaragua and Colombia as parts of the relevant coast,
contributing “base points for the construction of the provisional median line” with regard to the
continental shelf and the exclusive economic zone (Territorial and Maritime Dispute (Nicaragua v.
Colombia), Judgment, I.C.J. Reports 2012 (II), pp. 698-699, para. 201). According to that
Judgment, the coasts of the Corn Islands did not “add to the length of the relevant coast”, but this
was for a reason that does not apply in the present case, namely that in relation to Colombia’s
islands the Corn Islands were “parallel to the mainland” (ibid., p. 678, para. 145).
113. The coasts of the Corn Islands that do not face north also have to be included when
determining the length of the relevant coasts. On the other hand, no evidence concerning the
capacity of the Cayos de Perlas to “sustain human habitation or economic life of their own” as
required by Article 121 of UNCLOS was supplied by Nicaragua to support its assertion that “the
Cayos de Perlas generate maritime projections”. Therefore their coasts should not be included
among the relevant coasts.
114. Given the fact that the relevant coasts of Nicaragua and Costa Rica are not
characterized by sinuosity, the length of the relevant coasts should preferably be measured on the
basis of their natural configuration. This results in a total length of the coasts of 228.8 km for
Costa Rica and of 465.8 km for Nicaragua, with a ratio of 1:2.04 in favour of Nicaragua (see
sketch-map No. 8 below).
- 48 -
- 49 -
(ii) Relevant area
115. As the Court indicated in Territorial and Maritime Dispute (Nicaragua v. Colombia),
“[t]he relevant area comprises that part of the maritime space in which the potential entitlements of
the parties overlap” (Judgment, I.C.J. Reports 2012 (II), p. 683, para. 159).
116. The Court also recalls its observation that “the legal concept of the ‘relevant area’ has to
be taken into account as part of the methodology of maritime delimitation” (Maritime Delimitation
in the Black Sea (Romania v. Ukraine), Judgment, I.C.J. Reports 2009, p. 99, para. 110).
Moreover, “[d]epending on the configuration of the relevant coasts in the general geographical
context, the relevant area may include certain maritime spaces and exclude others which are not
germane to the case in hand” (Territorial and Maritime Dispute (Nicaragua v. Colombia),
Judgment, I.C.J. Reports 2012 (II), p. 682, para. 157).
*
117. The Parties agree that the relevant area should not include the spaces attributed to
Colombia on the basis of the 2012 Judgment and those attributed to Panama by the 1980 bilateral
treaty concluded with Costa Rica. This conforms with what the Court stated in Territorial and
Maritime Dispute (Nicaragua v. Colombia) (Judgment, I.C.J. Reports 2012 (II), p. 685, para. 163):
“The Court recalls that the relevant area cannot extend beyond the area in which
the entitlements of both Parties overlap. Accordingly, if either Party has no entitlement
in a particular area, whether because of an agreement it has concluded with a third
State or because that area lies beyond a judicially determined boundary between that
Party and a third State, that area cannot be treated as part of the relevant area for
present purposes.”
118. In the north, in order to determine the relevant area, Nicaragua submits that a
perpendicular line to the general direction of the coast should be drawn starting from Coconut Point
until it reaches the boundary with Colombia (see sketch-map No. 7 above). Costa Rica contends
that the relevant area should also comprise waters falling “within the radial projection of other parts
of coast that are relevant”. This would increase the part of the relevant area attributed to Nicaragua
(see sketch-map No. 6 above).
119. To define the relevant area in the south, Costa Rica adopts a notional line continuing
along the direction of its maritime boundary with Panama as set out in their bilateral treaty of 1980.
Nicaragua’s position on the relevant area is that it should be bounded to the south by the lines
drawn in the 1980 treaty between Costa Rica and Panama and in the 1977 treaty between
Costa Rica and Colombia (see orange area on sketch-map No. 7 above). However, Nicaragua
contends that, if the Court were to adopt Costa Rica’s position on the 1977 treaty and extend the
relevant area beyond the limits set out therein, that area should be bounded by the line drawn in the
- 50 -
1976 treaty between Panama and Colombia (see light brown area on sketch-map No. 7). Nicaragua
rejects Costa Rica’s approach of using the notional extension of the line set out in the 1980 treaty to
define the relevant area as it would exclude an area to the south of that line where only Costa Rica
or Nicaragua may have claims.
*
120. The Court considers that, except for the space attributed to Colombia in the
2012 Judgment, the area where there are overlapping projections in the north includes the whole
maritime space situated within a distance of 200 nautical miles from Costa Rica’s coast.
121. In the south, the situation is more complicated because of the presence of claims of
third States on which the Court cannot pronounce itself (see sub-section (b) below). The impact of
the rights of third States in the areas that may be attributed to one of the Parties cannot be
determined, but the spaces where third States have a claim may nevertheless be included. In the
Maritime Delimitation in the Black Sea case (Romania v. Ukraine) (Judgment, I.C.J. Reports 2009,
p. 100, para. 114), the Court observed that:
“where areas are included solely for the purpose of approximate identification of
overlapping entitlements of the Parties to the case, which may be deemed to constitute
the relevant area (and which in due course will play a part in the final stage testing for
disproportionality), third party entitlements cannot be affected”.
122. The Court will further analyse the issue of the relevant area in sub-section (e) below.
(b) Relevance of bilateral treaties and judgments involving third States
123. An issue is raised by the fact that, in the area of the Caribbean Sea in which the Court is
requested to delimit the maritime boundary between the Parties, third States may also have claims.
As was stated in Territorial and Maritime Dispute (Nicaragua v. Colombia), the Court’s Judgment
may only address the maritime boundary between the Parties, “without prejudice to any claim of a
third State or any claim which either Party may have against a third State” (Judgment, I.C.J.
Reports 2012 (II), p. 707, para. 228). The Judgment can refer to those claims, but cannot determine
whether they are well founded. Conversely, a judgment rendered by the Court between one of the
Parties and a third State or between two third States cannot per se affect the maritime boundary
between the Parties. The same applies to treaties concluded between one of the Parties and a third
State or between third States.
*
- 51 -
124. Nicaragua acknowledges that treaties cannot be relied on by States that are not party to
them, but nevertheless presents arguments concerning maritime delimitation on the basis of three
treaties to which it is not a party, one between Costa Rica and Colombia, another between
Costa Rica and Panama and the last between Colombia and Panama. With regard to the
1977 Treaty on Delimitation of Marine and Submarine Areas and Maritime Cooperation between
Costa Rica and Colombia, Nicaragua argues that this treaty “fixed and limited Costa Rica’s
interests in the maritime spaces of the Caribbean Sea” and that it consolidated Costa Rica’s
potential claims in the area.
125. Moreover, Nicaragua states that although the treaty between Costa Rica and Colombia
has not been ratified, it “was in fact enforced according to its provisions”. According to Nicaragua,
compliance by Costa Rica with the terms of the treaty for approximately 40 years generated
binding obligations for Costa Rica. In Nicaragua’s view, statements made by Costa Rica
“constituted an irrevocable commitment to ratify [the treaty], once all the parliamentary
requirements had been satisfied”.
126. Nicaragua claims that the boundary established by the 1977 Treaty between Costa Rica
and Colombia must be taken into account in the delimitation between the Parties in the present case
in the exclusive economic zone and continental shelf. That boundary, in Nicaragua’s view,
“defines  and limits  the extent of Costa Rica’s maritime areas in the Caribbean Sea” and
prevents Costa Rica from claiming any area to the north and east of that line.
127. According to Nicaragua, “there can have been no vacuum in the areas of the
South-Western Caribbean attributed to Colombia in its 1977 Treaty with Costa Rica. If the areas
were not claimed by Costa Rica in 1977, they appertained to Colombia: and following the Court’s
Judgment of 2012, some of those areas now belong to Nicaragua.”
128. With regard to the 1980 Treaty between Costa Rica and Panama, Nicaragua
acknowledges that this treaty is also res inter alios acta in relation to Nicaragua, but nevertheless it
argues that the treaty creates “a legal régime and scenario which the Court cannot ignore”.
According to Nicaragua, Article 1 of the treaty establishes a tripoint at the intersection of the
boundaries concerning Costa Rica, Colombia and Panama. This provision, in Nicaragua’s view,
also gives effect to the 1977 Treaty between Costa Rica and Colombia.
129. Concerning the 1976 Treaty between Colombia and Panama, Nicaragua argues that
Panama can no longer have any claim in the area north of the boundary line, because it would be
incompatible with that treaty. In Nicaragua’s view, also Colombia cannot have any claim in that
area, as this would be incompatible with the boundary drawn by the Court in Territorial and
Maritime Dispute (Nicaragua v. Colombia). Therefore, only Nicaragua or Costa Rica may have
claims in that area.
- 52 -
130. In its Counter-Memorial, Nicaragua observes that the 2012 Judgment of the Court is not
binding on Costa Rica, but that “a departure from its findings would be warranted only if new and
compelling elements would justify such a departure”.
131. With regard to the 1977 Treaty between Costa Rica and Colombia, Costa Rica argues
that this treaty has not been ratified and that thus, according to its terms, it has never entered into
force and cannot have the same effects as if it were ratified. Despite Costa Rica’s practice of
compliance with regard to the boundary fixed by the treaty, the latter is res inter alios acta in
relation to Nicaragua and should not be taken into account in the present case. Costa Rica further
asserts that the treaty could not produce any erga omnes effects. Moreover, following the Court’s
2012 Judgment in the case concerning Territorial and Maritime Dispute (Nicaragua v. Colombia),
Costa Rica indicated in a note to Colombia that it considered the treaty to be “impracticable” and
“ineffective”. It maintains that the two countries no longer share an area of overlapping maritime
entitlements. Referring to the 1980 Treaty between Costa Rica and Panama, Costa Rica argues that
the fact that this treaty is undisputedly in force and that the boundary it establishes may connect at a
tripoint with the line fixed by the 1977 Treaty does not imply that the 1977 Treaty is in force.
132. In response to Nicaragua’s argument concerning Costa Rica’s practice with regard to
the 1977 Treaty, Costa Rica contends that its conduct cannot amount to any renunciation of its
rights in the maritime areas now at stake. Costa Rica maintains that the “provisional application of
a treaty that has not entered into force simply involves compliance with the provisions of the law of
treaties” and refers to the obligation, under Article 18 of the Vienna Convention on the Law of
Treaties, for a State which has signed a treaty to refrain from “acts which would defeat the object
and purpose” of the treaty before its ratification. Costa Rica stresses that on no occasion did it
renounce its right to assert its entitlement to maritime areas in the region with respect to Nicaragua.
133. With regard to the 1976 Treaty between Colombia and Panama, Costa Rica maintains
that this treaty cannot affect the rights of the Parties in the present case. Costa Rica argues that the
Court and international tribunals have consistently refused to consider treaties concluded with third
States or between third States when drawing the course of a maritime boundary. According to
Costa Rica, while these treaties may be used to set the limits of the relevant area and may influence
the endpoint of the maritime boundary, their bilateral character should be preserved and the Court
should not take them into account when drawing a maritime boundary between the Parties.
*
134. The Court observes that the 1976 Treaty between Panama and Colombia involves third
States and cannot be considered relevant for the delimitation between the Parties. With regard to
the 1977 Treaty between Costa Rica and Colombia, there is no evidence that a renunciation by
Costa Rica of its maritime entitlements, if it had ever taken place, was also intended to be effective
with regard to a State other than Colombia.
- 53 -
(c) Provisional equidistance line
135. In order to define the single maritime boundary concerning the exclusive economic
zone and the continental shelf, the Court has to “achieve an equitable solution” according to
Articles 74 and 83 of UNCLOS. The Court will delimit the exclusive economic zone and the
continental shelf pursuant to its established methodology in three stages. First, it will provisionally
draw an equidistance line using the most appropriate base points on the relevant coasts of the
Parties. Second, it will consider whether there exist relevant circumstances which are capable of
justifying an adjustment of the equidistance line provisionally drawn. Third, it will assess the
overall equitableness of the boundary resulting from the first two stages by checking whether there
exists a marked disproportionality between the length of the Parties’ relevant coasts and the
maritime areas found to appertain to them (Maritime Delimitation in the Black Sea (Romania v.
Ukraine), Judgment, I.C.J. Reports 2009, pp. 101-103, paras. 115-122; Territorial and Maritime
Dispute (Nicaragua v. Colombia), Judgment, I.C.J. Reports 2012 (II), pp. 695-696, paras. 190-193;
Maritime Dispute (Peru v. Chile), Judgment, I.C.J. Reports 2014, p. 65, para. 180). The Court
notes that the methodology in three stages set out in its Judgment in Maritime Delimitation in the
Black Sea (Romania v. Ukraine) has also been adopted by other international tribunals requested to
delimit maritime boundaries (see e.g. Delimitation of the Maritime Boundary in the Bay of Bengal
(Bangladesh/Myanmar), Judgment, ITLOS Reports 2012, pp. 64-68, paras. 225-240; Bay of Bengal
Maritime Boundary Arbitration (Bangladesh v. India), Award of 7 July 2014, International Law
Reports, Vol. 167, pp. 111-114, paras. 336-346).
136. With regard to the first stage of the delimitation, the Court, in Maritime Delimitation in
the Black Sea (Romania v. Ukraine), stated that:
“First, the Court will establish a provisional delimitation line, using methods
that are geometrically objective and also appropriate for the geography of the area in
which the delimitation is to take place. So far as delimitation between adjacent coasts
is concerned, an equidistance line will be drawn unless there are compelling reasons
that make this unfeasible in the particular case” (Judgment, I.C.J. Reports 2009,
p. 101, para. 116).
As the Court observed in that Judgment, “[t]he line thus adopted is heavily dependent on the
physical geography and the most seaward points of the two coasts” (ibid., para. 117). However, the
Court also noted that, “[w]hen placing base points on very small maritime features would distort
the relevant geography, it is appropriate to disregard them in the construction of a provisional
median line” (Territorial and Maritime Dispute (Nicaragua v. Colombia), Judgment, I.C.J.
Reports 2012 (II), p. 699, para. 202).
137. The seaward endpoint of the delimitation of the territorial sea, as determined above (see
paragraph 106), constitutes the starting-point of the provisional equidistance line.
- 54 -
138. The Court has already observed when considering the median line relating to the
territorial sea that the Parties construct their respective equidistance lines by using base points that
are placed on natural coasts. The same applies with regard to the equidistance lines proposed by the
Parties concerning the exclusive economic zone and the continental shelf.
*
139. The Parties are generally in agreement with regard to the selection of base points, but
are divided on two issues. The first issue concerns the placement of base points on the
Corn Islands. Costa Rica contests this placement. Costa Rica acknowledges that, in Territorial and
Maritime Dispute (Nicaragua v. Colombia), “[t]hese same Nicaraguan features were given full
effect in the delimitation with Colombia”, but argues that in that case the delimitation was
different, because it concerned “the opposite coasts of opposing islands” and not adjacent coasts.
Nicaragua contends that, considering the Corn Islands’ vicinity to the mainland, “to ignore [them]
as base points would . . . effectively erase an integral component of Nicaragua’s coast from the
map”. Nicaragua points out that the Corn Islands are capable of generating an exclusive economic
zone and a continental shelf.
*
140. The Court concludes that base points should be placed on the Corn Islands for the
purpose of constructing a provisional equidistance line. These islands have a significant number of
inhabitants and sustain economic life. They therefore amply satisfy the requirements set forth in
Article 121 of UNCLOS for an island to be entitled to generate an exclusive economic zone and
continental shelf. The effect that has to be attributed to the Corn Islands in the adjusted delimitation
is a different question, that should not affect the construction of the provisional equidistance line.
* *
141. The other issue relating to the base points concerns some minor maritime features,
Paxaro Bovo and Palmenta Cays, which are situated at a short distance from Nicaragua’s mainland
coast near Punta del Mono. Costa Rica argues that base points should not be placed on small
insular features located along the coast and stresses that islets, cays and rocks do not generate
entitlements to an exclusive economic zone or a continental shelf. In Costa Rica’s view, placing
base points on those features would create an “excessive and disproportionate distortion” of the
provisional equidistance line. Nicaragua does not argue that these small islands are capable of
- 55 -
generating a claim to an exclusive economic zone or to a continental shelf. According to
Nicaragua, however, these maritime features can provide base points for the construction of the
provisional equidistance line because they are “fringing islands” that “form an integral part of
Nicaragua’s coast”. The assimilation of these islands to the coast is contested by Costa Rica.
*
142. The Court notes that the Palmenta Cays are islets lying at a distance of about one
nautical mile from the coast. When considering base points for the construction of an equidistance
line, the Court referred to “a cluster of fringe islands” in Maritime Delimitation in the Black Sea
(Romania v. Ukraine) (Judgment, I.C.J. Reports 2009, p. 109, para. 149) and to “islands fringing
the Nicaraguan coast” in Territorial and Maritime Dispute (Nicaragua v. Colombia) (Judgment,
I.C.J. Reports 2012 (II), p. 678, para. 145; see also ibid., p. 699, para. 201). Such formations may
be assimilated to the coast. Palmenta Cays fit this description. The same conclusion may apply with
regard to Paxaro Bovo, which is a rock situated 3 nautical miles off the coast south of
Punta del Mono. The Court considers it appropriate to place base points on both features for the
construction of the provisional equidistance line.
143. In the construction of the provisional equidistance line relating to the exclusive
economic zone and to the continental shelf, the Court will again select base points located on the
natural coast and on solid land (see paragraph 100 above).
144. As already stated, the construction of this line is without prejudice to any claims that a
third State may have on part of the area crossed by the line.
145. The provisional equidistance line shall follow a series of geodetic lines connecting the
points having the following co-ordinates in WGS 84 datum:
Turning point Latitude north Longitude west
Lx (endpoint of the delimitation
of the territorial sea)
11° 07' 28.8" 83° 36' 30.4"
1 11° 08' 08.3" 83° 35' 54.5"
2 11° 09' 01.3" 83° 35' 05.3"
3 11° 09' 11.5" 83° 34' 55.5"
4 11° 10' 20.9" 83° 33' 47.9"
5 11° 10' 49.9" 83° 33' 17.2"
6 11° 11' 08.1" 83° 32' 57.1"
7 11° 11' 13.8" 83° 32' 50.5"
- 56 -
Turning point Latitude north Longitude west
8 11° 12' 39.0" 83° 31' 22.7"
9 11° 12' 56.2" 83° 31' 04.2"
10 11° 13' 06.0" 83° 30' 53.5"
11 11° 13' 07.3" 83° 30' 52.0"
12 11° 14' 03.7" 83° 29' 46.5"
13 11° 14' 56.5" 83° 20' 54.2"
14 11° 14' 56.4" 83° 17' 24.1"
15 11° 15' 02.4" 83° 07' 50.0"
16 11° 15' 06.1" 83° 03' 44.9"
17 11° 15' 39.2" 82° 47' 03.3"
18 11° 15' 42.5" 82° 45' 38.1"
19 11° 13' 29.7" 82° 40' 33.2"
20 11° 12' 03.5" 82° 37' 09.5"
21 11° 11' 52.0" 82° 36' 41.4"
22 11° 07' 19.5" 82° 25' 08.1"
23 11° 05' 11.7" 82° 19' 33.4"
24 11° 05' 01.1" 82° 18' 16.5"
25 11° 04' 55.4" 82° 17' 28.1"
26 11° 05' 06.1" 81° 58' 08.3"
27 11° 05' 03.4" 81° 38' 38.8"
28 11° 09' 58.0" 81° 06' 27.0"
29 11° 12' 24.8" 80° 46' 04.4"
From point 29, the provisional equidistance line continues along the geodetic line starting at an
azimuth of 82° 08' 29". The line is illustrated on sketch-map No. 9 below.
- 57 -
- 58 -
(d) Adjustment to the provisional equidistance line
146. After constructing the provisional equidistance line, “the Court will at the next, second
stage consider whether there are factors calling for the adjustment or shifting of the provisional
equidistance line in order to achieve an equitable result” (Maritime Delimitation in the Black Sea
(Romania v. Ukraine), Judgment, I.C.J. Reports 2009, p. 101, para. 120).
*
147. Both Parties are of the view that an adjustment of the provisional equidistance line for
the delimitation of the EEZ and continental shelf is necessary, but they rely on different
circumstances to support their claimed adjustment.
148. Nicaragua argues that it would suffer from a cut-off effect caused by “the convex and
north-facing nature of Costa Rica’s coastline at Punta Castilla immediately adjacent to Nicaragua’s
concave coastline” if the provisional equidistance line were adopted as the maritime boundary.
That cut-off has been invoked by Nicaragua also as a special circumstance requiring the adjustment
of the equidistance line in the territorial sea. According to Nicaragua, its effects persist beyond the
limits of the territorial sea, up to a distance of at least 65 nautical miles. Nicaragua argues that the
combination of the convexity of Costa Rica’s coast with the concavity of Nicaragua’s coast forces
the equidistance line to take a sharp angle in front of Nicaragua’s coast, to its disadvantage.
Nicaragua contends that the line must be adjusted in order to achieve an equitable result.
149. Costa Rica contests Nicaragua’s argument. According to Costa Rica, the convexity and
concavity invoked by Nicaragua are “microgeographical” and cannot be characterized as “marked”.
It maintains that “Nicaragua’s cut-off is inevitable, but it is not inequitable”. Costa Rica moreover
contends that the combination of convexity and concavity can only be relevant when a State
occupies a central position between two States along a convex or concave coast: since Nicaragua
does not find itself in a three-State-concavity situation, it cannot claim to suffer such a cut-off.
150. In order to support an adjustment to the provisional equidistance line to its own
advantage, Costa Rica refers to what it calls a notional delimitation, consisting of the prolongation
of the equidistance line agreed in the bilateral treaty with Panama. It indicates that the fact that it
finds itself in the situation of a “three-State concavity” where the “coastal concavity and the cut-off
created by that concavity in conjunction with a notional delimitation with a third State” creates an
inequitable delimitation. Costa Rica argues that its coast is “purely concave”, and that the
equidistance line produces a cut-off effect for Costa Rica’s seaward projections. According to
Costa Rica, this cut-off constitutes a relevant circumstance calling for the adjustment of the
provisional equidistance line in order to reach an equitable solution for both Parties. Costa Rica
recalls that the Court first enunciated the notion of cut-off in the North Sea Continental Shelf
(Federal Republic of Germany/Denmark; Federal Republic of Germany/Netherlands) cases and
- 59 -
that international tribunals have further confirmed that the provisional equidistance line should be
adjusted when a cut-off is created as a result of the concavity of the coast. Costa Rica observes that
its claimed adjustment would allow it to reach its full 200-nautical-mile entitlement.
151. Costa Rica further argues that if, contrary to its view, the Court were to find that the
Corn Islands should be taken as base points for the provisional equidistance line, the geographic
situation of these islands, and in particular their location at a distance from the mainland coast
should be considered as a relevant circumstance calling for an adjustment of the line. According to
Costa Rica, the Corn Islands should be given no effect.
152. Nicaragua rejects Costa Rica’s argument according to which it is suffering from “the
interplay between the delimitation with Nicaragua, on the one side, and the notional delimitation
with Panama, on the other”. In Nicaragua’s view, the relationship between Costa Rica and Panama
cannot be taken into account in the present proceedings, as it has nothing to do with Nicaragua.
Moreover, Nicaragua maintains that the jurisprudence does not recognize a right of States to have
their exclusive economic zones reach the limit of 200 nautical miles, irrespective of the geography
and the potential rights of third States. Nicaragua also dismisses Costa Rica’s contention according
to which the Corn Islands constitute a relevant circumstance calling for the adjustment of the
equidistance line. Nicaragua considers that the Corn Islands exert an influence on the course of the
equidistance line in the same way as base points placed on Costa Rica’s coast: “those influences are
mutual and balanced”. Nicaragua argues that the Corn Islands must be given full weight.
*
153. With regard to the effect to be given to the Corn Islands in the determination of the
maritime boundary, the Court observes that, while they are entitled to generate an exclusive
economic zone and a continental shelf, they are situated at about 26 nautical miles from the
mainland coast and their impact on the provisional equidistance line is out of proportion to their
limited size. As was noted by the International Tribunal for the Law of the Sea in Delimitation of
the Maritime Boundary in the Bay of Bengal (Bangladesh/Myanmar) (Judgment, ITLOS
Reports 2012, p. 86, para. 317):
“the effect to be given to an island in the delimitation of the maritime boundary in the
exclusive economic zone and the continental shelf depends on the geographic realities
and the circumstances of the specific case. There is no general rule in this respect.
Each case is unique and requires specific treatment, the ultimate goal being to reach a
solution that is equitable.”
154. In the case of the Corn Islands, the Court considers that, given their limited size and
significant distance from the mainland coast, it is appropriate to give them only half effect. This
produces an adjustment of the equidistance line in favour of Costa Rica.
- 60 -
155. The other arguments advanced by the Parties to support an adjustment of the
provisional equidistance line cannot be accepted. Nicaragua’s alleged combination of a convex
coast of Costa Rica near Punta de Castilla and of its own concave coast has a limited effect on the
boundary line, especially at a distance from the coast, and is not sufficiently significant to warrant
an adjustment of the line.
156. The overall concavity of Costa Rica’s coast and its relations with Panama cannot justify
an adjustment of the equidistance line in its relations with Nicaragua. When constructing the
maritime boundary between the Parties, the relevant issue is whether the seaward projections from
Nicaragua’s coast create a cut-off for the projections from Costa Rica’s coast as a result of the
concavity of that coast. This alleged cut-off is not significant, even less so once the equidistance
line has been adjusted by giving a half effect to the Corn Islands.
157. The adjusted equidistance line of the exclusive economic zone and continental shelf is
obtained by joining with geodetic lines the points with the following co-ordinates in WGS 84
datum:
Turning point Latitude north Longitude west
Lx (endpoint of the delimitation
of the territorial sea)
11° 07' 28.8" 83° 36' 30.4"
1 11° 08' 08.3" 83° 35' 54.5"
2 11° 09' 01.3" 83° 35' 05.3"
3 11° 09' 11.5" 83° 34' 55.5"
4 11° 10' 20.9" 83° 33' 47.9"
5 11° 10' 49.9" 83° 33' 17.2"
6 11° 11' 08.1" 83° 32' 57.1"
7 11° 11' 13.8" 83° 32' 50.5"
8 11° 12' 39.0" 83° 31' 22.7"
9 11° 12' 56.2" 83° 31' 04.2"
10 11° 13' 06.0" 83° 30' 53.5"
11 11° 13' 07.3" 83° 30' 52.0"
12 11° 14' 03.7" 83° 29' 46.5"
13 11° 14' 56.5" 83° 20' 54.2"
14 11° 14' 56.4" 83° 17' 24.1"
15 11° 15' 02.4" 83° 07' 50.0"
16 11° 15' 06.1" 83° 03' 44.9"
17 11° 15' 39.2" 82° 47' 03.3"
18 11° 15' 42.5" 82° 45' 38.1"
19' 11° 14' 39.4" 82° 40' 02.5"
- 61 -
Turning point Latitude north Longitude west
20' 11° 13' 58.8" 82° 36' 20.2"
21' 11° 13' 53.6" 82° 35' 51.2"
22' 11° 13' 28.0" 82° 33' 20.0"
23' 11° 11' 56.7" 82° 24' 06.7"
24' 11° 11' 54.6" 82° 23' 53.6"
25' 11° 11' 54.0" 82° 23' 49.7"
26' 11° 11' 49.5" 82° 23' 20.7"
27' 11° 11' 01.9" 82° 18' 01.5"
28' 11° 11' 00.8" 82° 17' 29.5"
29' 11° 11' 00.3" 82° 17' 08.0"
30' 11° 11' 19.6" 82° 08' 49.8"
31' 11° 11' 39.3" 81° 59' 01.5"
32' 11° 11' 43.5" 81° 58' 01.0"
33' 11° 11' 51.9" 81° 57' 00.7"
34' 11° 14' 58.9" 81° 39' 24.5"
35' 11° 19' 31.9" 81° 21' 43.1"
36' 11° 21' 24.5" 81° 10' 12.0"
37' 11° 21' 31.1" 81° 09' 34.5"
38' 11° 21' 40.2" 81° 08' 50.2"
39' 11° 21' 47.5" 81° 08' 17.4"
40' 11° 21' 52.2" 81° 07' 55.4"
41' 11° 25' 59.0" 80° 47' 51.3"
From point 41', the delimitation line continues along the geodetic line starting at an azimuth of
77° 49' 08". As already noted (see paragraph 144 above), this line is constructed without prejudice
to any claims that a third State may have on part of the area crossed by the line. The line is
illustrated on sketch-map No. 10 below.
- 62 -
- 63 -
158. Given the complexity of the line described in the previous paragraph, the Court
considers it more appropriate to adopt a simplified line, on the basis of the most significant turning
points on the adjusted equidistance line, which indicate a change in the direction of that line. The
resulting simplified line is composed of the points with the following co-ordinates in WGS 84
datum:
Turning point Latitude north Longitude west
Lx (endpoint of the
delimitation of the territorial
sea)
11° 07' 28.8" 83° 36' 30.4"
M 11° 08' 08.3" 83° 35' 54.5"
N 11° 14' 03.7" 83° 29' 46.5"
O 11° 14' 56.5" 83° 20' 54.2"
P 11° 15' 42.5" 82° 45' 38.1"
Q 11° 11' 00.8" 82° 17' 29.5"
R 11° 11' 43.5" 81° 58' 01.0"
S 11° 14' 58.9" 81° 39' 24.5"
T 11° 19' 31.9" 81° 21' 43.1"
U 11° 21' 31.1" 81° 09' 34.5"
V 11° 25' 59.0" 80° 47' 51.3"
From point V, the delimitation line continues along the geodetic line starting at an azimuth of
77° 49' 08". This line is illustrated on sketch-map No. 11 below.
- 64 -
- 65 -
(e) Disproportionality test
159. As the Court stated in the case concerning Maritime Delimitation in the Black Sea
(Romania v. Ukraine):
“Finally, and at a third stage, the Court will verify that the line (a provisional
equidistance line which may or may not have been adjusted by taking into account the
relevant circumstances) does not, as it stands, lead to an inequitable result by reason of
any marked disproportion between the ratio of the respective coastal lengths and the
ratio between the relevant maritime area of each State by reference to the delimitation
line” (Judgment, I.C.J. Reports 2009, p. 103, para. 122).
160. The Court also referred to the need for “a confirmation that no great disproportionality
of maritime areas is evident by comparison to the ratio of coastal lengths” (ibid., para. 122).
161. In Territorial and Maritime Dispute (Nicaragua v. Colombia), the Court explained that:
“[i]n carrying out this third stage, the Court . . . is not applying a principle of strict
proportionality. Maritime delimitation is not designed to produce a correlation
between the lengths of the Parties’ relevant coasts and their respective shares of the
relevant area . . . The Court’s task is to check for a significant disproportionality. What
constitutes such a disproportionality will vary according to the precise situation in
each case, for the third stage of the process cannot require the Court to disregard all of
the considerations which were important in the earlier stages.” (Territorial and
Maritime Dispute (Nicaragua v. Colombia), Judgment, I.C.J. Reports 2012 (II),
p. 715, para. 240.)
Therefore, at this stage in delimitation, the Court will endeavour to “ensure that there is not a
disproportion so gross as to ‘taint’ the result and render it inequitable” (ibid., p. 716, para. 242).
Whether there is significant disproportionality “remains in each case a matter for the Court’s
appreciation, which it will exercise by reference to the overall geography of the area” (Maritime
Delimitation in the Black Sea (Romania v. Ukraine), Judgment, I.C.J. Reports 2009, p. 129,
para. 213).
162. In Territorial and Maritime Dispute (Nicaragua v. Colombia), the Court also explained
that:
“[t]he calculation of the relevant area does not purport to be precise but is only
approximate and ‘[t]he object of delimitation is to achieve a delimitation that is
equitable, not an equal apportionment of maritime areas’” (Judgment, I.C.J.
Reports 2012 (II), p. 683, para. 158, citing Maritime Delimitation in the Black Sea
(Romania v. Ukraine), Judgment, I.C.J. Reports 2009, p. 100, para. 111).
163. The relevant coastal lengths and their ratio have already been identified (see
paragraph 114 above). What still needs to be determined is the size of the maritime area
appertaining to each Party as a result of the construction of the maritime boundary.
- 66 -
164. The Court observes that the attribution of some maritime space to a third State will
affect the part of the relevant area that appertains to each Party. Since the maritime space
appertaining to third States cannot be identified in the present proceedings, it is impossible for the
Court to calculate precisely the part of the relevant area of each Party. However, for the purpose of
verifying whether the maritime delimitation shows a gross disproportion, an approximate
calculation of the relevant area is sufficient. In the present case, the Court finds it appropriate to
base this calculation on the “notional extension of the Costa Rica-Panama boundary” as suggested
by Costa Rica (see paragraph 119 above).
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165. On the foregoing basis, the relevant area (see sketch-map No. 12 above) would be
divided by the maritime boundary into 73,968 sq km for Nicaragua and 30,873 sq km for
Costa Rica, with a resulting ratio of 1:2.4 in favour of Nicaragua. The comparison with the ratio of
coastal lengths (1:2.04 also in favour of Nicaragua: see paragraph 114 above) does not show any
“marked disproportion”.
166. The Court therefore finds that the delimitation concerning the exclusive economic zone
and the continental shelf between the Parties in the Caribbean Sea shall follow the line described in
paragraph 158.
- 68 -
- 69 -
V.MARITIME DELIMITATION IN THE PACIFIC OCEAN
167. The Court now turns to the delimitation of the maritime boundary between the Parties
in the Pacific Ocean. As with the maritime delimitation in the Caribbean Sea, the Court was
requested with respect to the Pacific Ocean to delimit the boundary for the territorial sea, the
exclusive economic zone and the continental shelf. The maritime boundaries claimed by each Party
are depicted in sketch-map No. 14 below.
- 70 -
- 71 -
168. Following its established jurisprudence, the Court will delimit the maritime boundary in
the Pacific Ocean pursuant to the same methods used in delimiting the territorial sea, the exclusive
economic zone and the continental shelf in the Caribbean Sea (see paragraphs 98 and 135 above).
A. Starting-point of the maritime delimitation
169. Costa Rica and Nicaragua agree that the starting-point of the maritime boundary in the
Pacific Ocean is the midpoint of the closing line of Salinas Bay, and that such a closing line is the
one drawn between Punta Zacate, on Costa Rican territory, and Punta Arranca Barba, on
Nicaraguan territory. According to Costa Rica, the co-ordinates of the midpoint of the closing line
of Salinas Bay are 11° 04' 00'' N, 85° 44' 28'' W. According to Nicaragua, the exact co-ordinates of
the midpoint of the closing line of Salinas Bay are 11° 03' 56.3'' N, 85° 44' 28.3'' W. In the oral
proceedings, Costa Rica raised no objection to using the co-ordinates indicated by Nicaragua in its
Counter-Memorial for the purposes of identifying the starting-point of the maritime boundary in
the Pacific Ocean. Therefore, on the basis of the agreement between the Parties, the Court finds
that the maritime boundary between Costa Rica and Nicaragua in the Pacific Ocean shall start at
the midpoint of the closing line of Salinas Bay, with co-ordinates 11° 03' 56.3'' N, 85° 44' 28.3'' W
(WGS 84 datum).
B. Delimitation of the territorial sea
170. In order to establish the median line in the territorial sea, Costa Rica selects a number of
base points. On its own coast, Costa Rica selects base points on some islets just off Punta Zacate
and Punta Descartes, as well as two points located on a seaward protrusion of the Santa Elena
Peninsula called Punta Blanca. Costa Rica states that the Santa Elena Peninsula has an area of some
286 sq km and a permanent population of more than 2,400 inhabitants, which Nicaragua does not
dispute. On Nicaragua’s coast, Costa Rica selects as base points certain features in the vicinity of
Punta Arranca Barba, Punta La Flor, Frailes Rocks and Punta Sucia. Costa Rica contends that there
are no special circumstances justifying an adjustment of the provisional equidistance line drawn in
the territorial sea. In particular, Costa Rica argues that the Santa Elena Peninsula could not be
considered to have a distorting effect on the equidistance line in the territorial sea. Therefore,
Costa Rica requests the Court to delimit the territorial sea in the Pacific Ocean in accordance with a
strict equidistance line.
171. Nicaragua agrees with Costa Rica on how to draw the provisional equidistance line in
the territorial sea in the Pacific Ocean, which includes the selection of base points both on
Costa Rica’s coast and on its own coast. However, Nicaragua argues that the configuration of the
coast in the immediate vicinity of Salinas Bay is a special circumstance requiring the Court to
adjust the equidistance line in the territorial sea. Specifically, Nicaragua contends that the
Santa Elena Peninsula has a distorting effect on the equidistance line, since, starting at the first
turning point controlled by the base points on Punta Blanca, it markedly cuts off Nicaragua’s
coastal projections in the territorial sea. Consequently, Nicaragua requests the Court to adjust the
equidistance line by discounting the base points on the Santa Elena Peninsula which would cause
the boundary to deflect towards Nicaragua’s coast.
*
- 72 -
172. In accordance with its established jurisprudence, the Court will apply Article 15 of
UNCLOS, quoted in paragraph 90 above, by first drawing a provisional median line, and
subsequently considering whether special circumstances exist which justify its adjustment (see
paragraph 98 above). The Court notes that Costa Rica drew straight baselines in the Pacific Ocean
by promulgating Decree 18581-RE of 14 October 1988. Nicaragua does not object to the drawing
of straight baselines by Costa Rica in the Pacific Ocean. However, Costa Rica has not relied on
such straight baselines in the present proceedings.
173. For the construction of the provisional median line in the present case, Costa Rica and
Nicaragua selected the same base points, which are located on certain prominent features on their
coasts (see paragraphs 170–171 above). The Court sees no reason to depart from the base points
selected by both Parties. Therefore, for the purposes of drawing the provisional median line in the
territorial sea, the Court will locate base points on certain features in the vicinity of Punta Zacate,
Punta Descartes and Punta Blanca on Costa Rica’s coast, and on certain features in the vicinity of
Punta Arranca Barba, Punta La Flor, Frailes Rocks and Punta Sucia on Nicaragua’s coast.
174. However, the Parties differ on whether the configuration of the coast constitutes a
special circumstance within the meaning of Article 15 of UNCLOS which would justify an
adjustment of the provisional median line in the territorial sea. The issue is whether locating base
points on the Santa Elena Peninsula has a significant distorting effect on the provisional median
line which would result in a cut-off of Nicaragua’s coastal projections within the territorial sea. As
the Court has noted, “islets, rocks and minor coastal projections” can have a disproportionate effect
on the median line (Maritime Delimitation and Territorial Questions between Qatar and Bahrain
(Qatar v. Bahrain), Merits, Judgment, I.C.J. Reports 2001, p. 114, para. 246, citing Continental
Shelf (Libyan Arab Jamahiriya/Malta), Judgment, I.C.J. Reports 1985, p. 48, para. 64, itself citing
North Sea Continental Shelf (Federal Republic of Germany/Denmark; Federal Republic of
Germany/Netherlands), Judgment, I.C.J. Reports 1969, p. 36, para. 57). Such an effect can call for
an adjustment of the provisional median line in the territorial sea. In the vicinity of Salinas Bay,
however, the Santa Elena Peninsula cannot be considered to be a minor coastal projection that has a
disproportionate effect on the delimitation line. The coast of the Santa Elena Peninsula accounts for
a large portion of Costa Rica’s coast in the area in which the Court is requested to delimit the
territorial sea. Moreover, the adjustment proposed by Nicaragua in the territorial sea would push
the boundary close to Costa Rica’s coast, thus significantly cutting off Costa Rica’s coastal
projections within the territorial sea.
175. The Court concludes that the territorial sea in the Pacific Ocean shall be delimited
between the Parties by means of a median line, starting at the midpoint of the closing line of
Salinas Bay, having the co-ordinates identified in paragraph 169 above. The median line shall be
drawn using the base points indicated in paragraph 173 above. The maritime boundary in the
territorial sea shall follow a series of geodetic lines connecting the points having the following
co-ordinates in WGS 84 datum:
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Turning point Latitude north Longitude west
Starting-point (SP) 11° 03' 56.3'' 85° 44' 28.3''
A 11° 03' 56.9'' 85° 45' 22.7''
B 11° 03' 57.4'' 85° 45' 38.5''
C 11° 03' 47.6'' 85° 46' 34.1''
D 11° 03' 53.7'' 85° 47' 11.1''
E 11° 03' 24.9'' 85° 49' 40.8''
F 11° 03' 18.5'' 85° 50' 02.6''
G 11° 02' 44.7'' 85° 51' 24.8''
H 11° 03' 13.3'' 85° 52' 47.9''
I 11° 04' 32.1'' 85° 55' 41.4''
J 11° 05' 12.9'' 85° 57' 19.4''
K 11° 05' 49.2'' 86° 00' 39.0''
The boundary in the territorial sea shall terminate at point Kx (with current co-ordinates
11° 05' 49.5" N and 86° 01' 21.7" W), at the intersection of the 12-nautical-mile line with the
geodetic line connecting point K with the first turning point on the provisional equidistance line in
the exclusive economic zone, identified as point 1 and having the co-ordinates indicated at
paragraph 188 below. The delimitation line is illustrated on sketch-map No. 15 below.
- 74 -
- 75 -
C. Delimitation of the exclusive economic zone
and the continental shelf
176. The Court will now delimit the maritime boundary between the Parties for the exclusive
economic zone and the continental shelf in the Pacific Ocean according to its established
methodology.
(a) Relevant coasts and relevant area
(i) Relevant coasts
177. Costa Rica argues that the entire Nicaraguan coast, from Punta Arranca Barba to
Punta Cosigüina, is relevant for the purposes of delimitation in the Pacific Ocean. Costa Rica also
argues that its own relevant coast is divided into two parts. A first part extends from Punta Zacate
down to Cabo Blanco on the Nicoya Peninsula, while a second part extends from Punta Herradura
down to Punta Salsipuedes. Costa Rica measures the length of the proposed relevant coast both by
following the natural configuration of the coast, and by using straight-line approximations of the
coast. Applying the former method, Nicaragua’s relevant coast would be 345 km long, and
Costa Rica’s would be 670 km long. Applying the latter method, Nicaragua’s relevant coast would
be 300 km long, and Costa Rica’s would be 415 km long (see sketch-map No. 16 below).
178. Nicaragua argues that its relevant coast in the Pacific Ocean runs from Punta La Flor on
Salinas Bay to Corinto Point. Concerning Costa Rica’s relevant coast, Nicaragua contends that it
only comprises the coast running from Punta Zacate on Salinas Bay to Punta Guiones on the
Nicoya Peninsula. Nicaragua measures the Parties’ relevant coasts using straight-line
approximations. Nicaragua argues that its relevant coast extends for 238 km, while Costa Rica’s
relevant coast extends for 144 km (see sketch-map No. 17 below).
*
179. The Court recalls that in order to consider a coast to be relevant for the purposes of
delimitation, it must generate projections which overlap with projections from the coast of the other
party (see paragraph 108 above). Since in the Pacific Ocean the coast of Costa Rica is characterized
by a certain degree of sinuosity, whereas the coast of Nicaragua largely develops along a straight
line, the Court considers it appropriate to identify the relevant coast of both Parties by means of
straight lines.
180. The Court notes that the Parties’ positions do not differ significantly with respect to the
identification of Nicaragua’s relevant coast. The Court finds that the entire Nicaraguan coast, from
Punta Arranca Barba to Punta Cosigüina, generates potential maritime entitlements overlapping
with those of Costa Rica. In the geographical circumstances of the present case, this conclusion
- 76 -
does not change whether potential maritime entitlements are generated by the method of radial
projections or by the method of frontal projections. The length of Nicaragua’s relevant coast, thus
identified and measured by the Court along a straight line, is 292.7 km long.
181. The Parties’ arguments concerning Costa Rica’s relevant coast differ significantly. The
Court is of the view that the coast of Costa Rica between Punta Guiones and Cabo Blanco, as well
as between Punta Herradura and Punta Salsipuedes, generates potential maritime entitlements
overlapping with those of the relevant coast of Nicaragua as identified in the previous paragraph.
Under the circumstances, the Court finds it appropriate to include within the relevant coast certain
parts of Costa Rica’s coast south of Punta Guiones. Neither Party argued that the stretch of
Costa Rica’s coast running from Cabo Blanco due north-east into Nicoya Gulf and down to
Punta Herradura should be included in the relevant coast. The Court notes that the coasts of
Nicoya Gulf face each other and considers that they are not relevant for the purposes of
delimitation. The Court concludes that the first segment of Costa Rica’s relevant coast runs along
the straight lines connecting Punta Zacate, Punta Santa Elena, Cabo Velas, Punta Guiones and
Cabo Blanco. The second segment of Costa Rica’s relevant coast runs along the straight lines
connecting Punta Herradura, the Osa Peninsula, Punta Llorona and Punta Salsipuedes. Costa Rica’s
relevant coast, thus identified and measured by the Court along straight lines, is 416.4 km long (see
sketch-map No. 18 below).
(ii) Relevant area
182. Costa Rica argues that maritime areas should be considered to be relevant for the
purposes of delimitation only if both Parties have a potential entitlement over such areas.
According to Costa Rica, the identification of the relevant area need not be precise. Costa Rica
identifies the relevant area by reference to radial coastal projections. The use of radial projections
produces a relevant area enclosed within the envelope of arcs having a 200-nautical-mile radius
identifying the area of overlapping potential entitlements between the Parties, and bordered in the
north by a straight line starting at Punta Cosigüina and perpendicular to the direction of the
Nicaraguan coast (see sketch-map No. 16 below).
- 77 -
- 78 -
183. Nicaragua agrees with Costa Rica that the relevant area is identified by reference to the
areas in which the potential maritime entitlements of the Parties overlap. However, Nicaragua
argues that the relevant area should be identified by using frontal coastal projections. Accordingly,
Nicaragua suggests that the relevant area should be enclosed by the 200-nautical-mile limits of the
exclusive economic zones of the Parties in the west, by a line perpendicular to the general direction
of Costa Rica’s coast between Cabo Velas and Punta Guiones and starting at Punta Guiones in the
south, and by a line perpendicular to the general direction of Nicaragua’s coast starting from
Corinto Point in the north (see sketch-map No. 17 below).
- 79 -
*
- 80 -
184. The Court recalls that the relevant area, the identification of which is part of the
established maritime delimitation methodology, includes the maritime spaces in which the potential
entitlements generated by the coasts of the Parties overlap (see paragraphs 115–116 above). In the
present case, the Court is of the view that both the potential maritime entitlements generated by the
northern part of Costa Rica’s relevant coast, and the potential maritime entitlements generated by
the southern part of Costa Rica’s relevant coast (paragraph 181 above), overlap with the potential
maritime entitlements generated by the relevant coast of Nicaragua. The Court is also of the view
that the relevant area is bordered in the north by a line starting at Punta Cosigüina and
perpendicular to the straight line approximating the general direction of Nicaragua’s coast (see
paragraph 180 above). In the west and in the south, the relevant area is limited by the envelope of
arcs marking the limits of the area in which the potential maritime entitlements of the Parties
overlap.
185. The coast extending from Cabo Blanco due north-east into Nicoya Gulf and down to
Punta Herradura does not generate potential maritime entitlements overlapping with those
generated by Nicaragua’s coast. Therefore, the Court finds that the maritime area landward of the
line joining Cabo Blanco to Punta Herradura and approximately corresponding to the waters of
Nicoya Gulf is not part of the relevant area for the purposes of the delimitation. The relevant area
thus identified measures approximately 164,500 sq km (see sketch-map No. 18 below).
- 81 -
- 82 -
(b) Provisional equidistance line
186. In order to draw the provisional equidistance line in the exclusive economic zone and
on the continental shelf, Costa Rica identifies on its own coast a number of base points on the
Santa Elena Peninsula, located on the features called Punta Blanca and Punta Santa Elena. In
addition, Costa Rica identifies one base point on the Nicoya Peninsula, located on Cabo Velas,
which controls the provisional equidistance line starting at a point situated at approximately
120 nautical miles from the coast of the Parties. On Nicaragua’s coast, Costa Rica identifies a
number of base points in the vicinity of Punta Sucia, Punta Pie del Gigante and Punta Masachapa.
Costa Rica submits that its provisional equidistance line and the Nicaraguan provisional
equidistance line are not materially different.
187. Nicaragua agrees that the base points selected by Costa Rica on the Nicaraguan coast
faithfully reflect the macro-geography of the area. However, Nicaragua notes that, were it not for
the existence of the Nicoya Peninsula, the provisional equidistance line would be essentially
perpendicular to the general direction of the coast of the Parties. Nevertheless, Nicaragua’s
provisional equidistance line does not differ from that suggested by Costa Rica. Nicaragua notes
that disagreements between the Parties on the maritime delimitation in the Pacific Ocean do not
relate to the first stage of the delimitation process, which concerns the drawing of a provisional
equidistance line.
*
188. The Court is satisfied that the base points selected by the Parties are appropriate for
drawing a provisional equidistance line in the Pacific Ocean. The provisional equidistance line for
the exclusive economic zone and the continental shelf shall begin at the end of the boundary in the
territorial sea (see paragraph 175 above), and thence it shall follow a series of geodetic lines
connecting the points having the following co-ordinates in WGS 84 datum:
Turning point Latitude north Longitude west
Kx (endpoint of the delimitation
of the territorial sea)
11° 05' 49.5" 86° 01' 21.7"
1 11° 05' 51.0" 86° 04' 44.7"
2 11° 06' 18.2'' 86° 07' 06.2''
3 11° 05' 08.3'' 86° 17' 40.0''
4 11° 04' 26.2'' 86° 21' 45.0''
5 11° 03' 51.5'' 86° 24' 18.7''
6 10° 56' 41.7'' 86° 45' 05.0''
7 10° 50' 50.5'' 86° 56' 32.2''
8 10° 36' 27.5'' 87° 23' 48.0''
9 10° 21' 17.1'' 87° 47' 54.5''
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189. From point 1 to point 8, the provisional equidistance line is controlled, on Costa Rica’s
side, by the base points located on the Santa Elena Peninsula. At point 9 the provisional
equidistance line begins to be controlled by the base point located on Cabo Velas, on the
Nicoya Peninsula. From point 9, the provisional equidistance line continues along the geodetic line
starting at an azimuth of 245° 38' 27.4'' until it reaches the 200-nautical-mile outer limit of the
exclusive economic zone of the Parties (see sketch-map No. 19 below).
- 84 -
- 85 -
(c) Adjustment to the provisional equidistance line
190. Costa Rica argues that the question whether it is necessary to adjust the provisional
equidistance line should be assessed by reference to coastal geography. Costa Rica maintains that
there is no relevant circumstance which could justify an adjustment of the provisional equidistance
line in the Pacific Ocean. Costa Rica submits that the Santa Elena Peninsula and the
Nicoya Peninsula are significant geographical features which are not capable of producing an
inequitable effect by distorting the provisional equidistance line to the detriment of Nicaragua.
Costa Rica asserts that the Nicoya Peninsula, which is an area of approximately 7,500 sq km and
has approximately 264,000 inhabitants, is an example of a substantial geographical feature that
cannot be refashioned by giving it less than full effect in establishing the maritime boundary
between the Parties in the Pacific Ocean. Costa Rica also contends that the disparity between the
length of the relevant coasts of the Parties is not sufficiently marked to require adjusting the
provisional equidistance line, and that there is no coastal concavity that inequitably cuts off
Nicaragua’s coastal projections. Therefore, Costa Rica requests the Court to refrain from making
any adjustment of the provisional equidistance line.
191. Nicaragua agrees with Costa Rica that the relevant circumstances which might justify
the adjustment of the provisional equidistance line could be generally geographical in character.
Nicaragua contends that the provisional equidistance line in the Pacific Ocean produces a marked
and unjustified cut-off of its coastal projections. According to Nicaragua, the direction of the coasts
of the Santa Elena Peninsula and of the Nicoya Peninsula does not correspond to the general
direction of Costa Rica’s coast. Nicaragua considers that placing base points on these features leads
to a provisional equidistance line which veers to the north, thus cutting off Nicaragua’s coastal
projections. Nicaragua argues that placing base points on the Santa Elena Peninsula and on the
Nicoya Peninsula would excessively distort the provisional equidistance line were it not adjusted.
Nicaragua contends that an equitable solution in respect of the exclusive economic zone and the
continental shelf could be achieved by giving half effect both to the Santa Elena Peninsula and to
the Nicoya Peninsula.
*
192. The arguments of the Parties concerning the adjustment of the provisional equidistance
line pertain to two distinct issues: first, whether the existence of the Santa Elena Peninsula results
in an inequitable cut-off of Nicaragua’s coastal projections; second, whether the existence of the
Nicoya Peninsula similarly creates an inequitable cut-off of Nicaragua’s coastal projections.
193. The Santa Elena Peninsula is a protrusion lying close to the starting-point of the
maritime boundary between the Parties. The Court has already found that the effect produced by
the Santa Elena Peninsula within the territorial sea does not justify an adjustment of the provisional
median line within 12 nautical miles (see paragraph 174 above). However, the situation is different
for the exclusive economic zone and the continental shelf, for which the base points placed on the
Santa Elena Peninsula control the course of the provisional equidistance line from the
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12-nautical-mile limit of the territorial sea up to a point located approximately 120 nautical miles
from the coasts of the Parties. The Court considers that such base points have a disproportionate
effect on the direction of the provisional equidistance line. The Court also considers that, beyond
the territorial sea, the effect of the Santa Elena Peninsula on the provisional equidistance line
results in a significant cut-off of Nicaragua’s coastal projections. In the view of the Court, this
cut-off effect is inequitable.
194. Therefore, the Court finds it appropriate to adjust the provisional equidistance line for
the exclusive economic zone and the continental shelf. In doing so, the Court is mindful of the
requirement that delimitation in the exclusive economic zone and on the continental shelf shall
“achieve an equitable solution” in accordance with Articles 74 and 83 of UNCLOS. The Court
recalls that any adjustment effected to remedy an inequitable cut-off to the detriment of Nicaragua
must not create an inequitable cut-off to the detriment of Costa Rica (see Territorial and Maritime
Dispute (Nicaragua v. Colombia), Judgment, I.C.J. Reports 2012 (II), p. 704, para. 216). In the
circumstances of the present case, the Court considers that an appropriate method to abate the cutoff
of Nicaragua’s coastal projections created by the presence of the Santa Elena Peninsula is to
give half effect to that peninsula. In the view of the Court, this decision contributes to the
achievement of an equitable solution.
195. The Court recalls that the Nicoya Peninsula is a feature with a large landmass,
corresponding to approximately one seventh of Costa Rica’s territory, and with a large population
(see paragraph 190 above). The coast of the Nicoya Peninsula accounts for a sizeable portion of the
coast of Costa Rica in the area to be delimited and, as a consequence, its direction cannot be said to
depart from the general direction of Costa Rica’s coast. The Court has drawn the provisional
equidistance line using Cabo Velas, located on the Nicoya Peninsula, as a base point. Cabo Velas
controls the equidistance line for approximately 80 nautical miles, from a point located at
approximately 120 nautical miles from the coast of the Parties to the endpoint of the maritime
boundary in the Pacific Ocean (see paragraphs 188-189 above).
196. In Delimitation of the Maritime Boundary in the Gulf of Maine Area (Canada/United
States of America), the Chamber of the Court rejected proposals to give less than full effect to
certain substantial mainland features. The Chamber stated that:
“the Parties have repeatedly charged each other with trying to refashion nature or
geography in the case of this or that feature of the area. It is not possible to accept the
United States claim that the south-westward protrusion of the Nova Scotian peninsula
from the Chignectou isthmus is an anomaly, a geographical distortion to be treated as
such, and to be considered an irregular derogation from the general south-southwest/
north-north-east trend of the eastern seaboard of the North American Continent.
It is likewise not possible to accept Canada’s claim that the existence of so substantial
a peninsula as Cap[e] Cod may be ignored because it forms a salient on the
Massachusetts coast on the western side of the Gulf of Maine. The Chamber must
recall that the facts of geography are not the product of human action amenable to
positive or negative judgment, but the result of natural phenomena, so that they can
only be taken as they are.” (Judgment, I.C.J. Reports 1984, p. 271, para. 37.)
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The Nicoya Peninsula is a prominent part of Costa Rica’s mainland and is comparable to the
Nova Scotian Peninsula or to Cape Cod; therefore, it cannot be given less than full effect in
delimiting the boundary in the exclusive economic zone and on the continental shelf.
197. Furthermore, it is well established that, in delimiting maritime boundaries, the Court
cannot disregard the geographical realities of the case before it. In North Sea Continental Shelf
(Federal Republic of Germany/Denmark; Federal Republic of Germany/Netherlands), the Court
stated that:
“[e]quity does not necessarily imply equality. There can never be any question of
completely refashioning nature, and equity does not require that a State without access
to the sea should be allotted an area of continental shelf, any more than there could be
a question of rendering the situation of a State with an extensive coastline similar to
that of a State with a restricted coastline. Equality is to be reckoned within the same
plane, and it is not such natural inequalities as these that equity could remedy.”
(Judgment, I.C.J. Reports 1969, pp. 49–50, para. 91.)
198. The Court considers that, in order to achieve an equitable solution, the provisional
equidistance line must be adjusted by giving half effect to the Santa Elena Peninsula. Since placing
base points on the Nicoya Peninsula does not lead to an inequitable solution, the Court also finds
that no adjustment is necessary on account of the presence of the Nicoya Peninsula. The Court is of
the view that its decision ensures the achievement of an equitable solution in accordance with
Articles 74 and 83 of UNCLOS.
199. In order to make this adjustment, the Court has drawn two lines, one giving full effect
and one giving no effect to the Santa Elena Peninsula for the exclusive economic zone and the
continental shelf (see sketch-map No. 20 below). Both the full effect and the no effect lines start at
the point at which the boundary in the territorial sea terminates (see paragraph 175 above). The line
giving full effect to the Santa Elena Peninsula corresponds to the provisional equidistance line
already drawn by the Court and described at paragraphs 188–189 above. The line giving no effect
to the Santa Elena Peninsula is obtained by discounting the Costa Rican base points located on the
Santa Elena Peninsula, while retaining the other base points on Costa Rica’s coast. The Court has
then drawn a line whose course lies midway between the full effect line and the no effect line,
which corresponds to the provisional equidistance line adjusted to give half effect to the
Santa Elena Peninsula.
200. The Court concludes that the maritime boundary in the exclusive economic zone and on
the continental shelf between Costa Rica and Nicaragua in the Pacific Ocean follows an
equidistance line starting at the endpoint of the boundary in the territorial sea (point Kx described
in paragraph 175 above), established using the base points mentioned in paragraphs 186-188 above,
and subsequently adjusted as described in paragraphs 198–199 above. The maritime boundary in
the exclusive economic zone and on the continental shelf shall therefore follow a series of geodetic
lines connecting the points having the following co-ordinates in WGS 84 datum:
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Turning point Latitude north Longitude west
Kx (endpoint of the delimitation
of the territorial sea)
11° 05' 49.5" 86° 01' 21.7"
1' 11° 04' 44.6" 86° 04' 45.2"
2' 11° 04' 42.6" 86° 04' 52.0"
3' 11° 04' 41.0" 86° 04' 58.5"
4' 11° 04' 11.6" 86° 07' 11.4"
5' 11° 00' 25.1" 86° 16' 59.0"
6' 10° 58' 53.3" 86° 20' 37.2"
7' 10° 57' 59.5" 86° 22' 36.3"
8' 10° 57' 30.0" 86° 23' 33.0"
9' 10° 56' 32.8" 86° 27' 24.2"
10' 10° 56' 30.5" 86° 27' 33.0"
11' 10° 54' 07.7" 86° 36' 39.6"
12' 10° 54' 03.9" 86° 36' 53.4"
13' 10° 53' 59.3" 86° 37' 08.7"
14' 10° 52' 07.4" 86° 43' 05.5"
15' 10° 47' 32.1" 86° 54' 46.9"
16' 10° 46' 31.9" 86° 57' 17.5"
17' 10° 46' 27.7" 86° 57' 27.6"
18' 10° 46' 23.5" 86° 57' 37.2"
19' 10° 42' 27.4" 87° 06' 09.7"
20' 10° 34' 41.9" 87° 22' 45.7"
21' 10° 30' 50.2" 87° 30' 16.1"
22' 10° 30' 48.6" 87° 30' 19.2"
23' 10° 30' 47.6" 87° 30' 20.9"
24' 10° 28' 13.7" 87° 34' 56.4"
9 (last turning point, same
as last turning point on
provisional equidistance line)
10° 21' 17.1" 87° 47' 54.5"
From point 9, the adjusted line continues along the geodetic line starting at an azimuth of
245° 38' 27.4'' until it reaches the 200-nautical-mile outer limits of the exclusive economic zones of
the Parties (see sketch-map No. 20 below).
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- 90 -
201. Given the complexity of the line described in the previous paragraph, the Court
considers it more appropriate to adopt a simplified line, on the basis of the most significant turning
points on the adjusted equidistance line, which indicate a change in the direction of that line. The
resulting simplified line is composed of the points with the following co-ordinates in WGS 84
datum:
Turning point Latitude north Longitude west
Kx (endpoint of the delimitation
of the territorial sea)
11° 05' 49.5" 86° 01' 21.7"
L 11° 04' 11.6" 86° 07' 11.4"
M 11° 00' 25.1" 86° 16' 59.0"
N 10° 57' 30.0" 86° 23' 33.0"
O 10° 54' 03.9" 86° 36' 53.4"
P 10° 52' 07.4" 86° 43' 05.5"
Q 10° 46' 27.7" 86° 57' 27.6"
R 10° 34' 41.9" 87° 22' 45.7"
S 10° 21' 17.1" 87° 47' 54.5"
From point S, the delimitation line continues along the geodetic line starting at an azimuth of
245° 38' 27.4" until it reaches the 200-nautical-mile line (see sketch-map No. 21 below).
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(d) Disproportionality test
202. The Court now turns to the disproportionality test, which is the third stage of the
methodology for the delimitation of maritime boundaries in the exclusive economic zone and on
the continental shelf (see paragraphs 159–161 above).
203. The relevant coast of Costa Rica in the Pacific Ocean is 416.4 km long (see
paragraph 181 above), and the relevant coast of Nicaragua in the Pacific Ocean is 292.7 km long
(see paragraph 180 above). The two relevant coasts stand in a ratio of 1:1.42 in favour of
Costa Rica. The Court finds that the maritime boundary it established between the Parties in the
Pacific Ocean divides the relevant area (see paragraphs 184–185 above) in such a way that
approximately 93,000 sq km of that area appertain to Costa Rica and 71,500 sq km of that area
appertain to Nicaragua. The ratio between the maritime areas found to appertain to the Parties
is 1:1.30 in Costa Rica’s favour. The Court considers that, taking into account all the circumstances
of the present case, the maritime boundary established between Costa Rica and Nicaragua in the
Pacific Ocean does not result in gross disproportionality. Accordingly, the Court finds that the
delimitation of the maritime boundary for the exclusive economic zone and the continental shelf
(see paragraph 201 above) achieves an equitable solution in accordance with Articles 74 and 83
of UNCLOS.
204. Consequently, the delimitation concerning the exclusive economic zone and the
continental shelf between the Parties in the Pacific Ocean shall follow the line described in
paragraph 201 above.
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*
* *
- 94 -
205. For these reasons,
THE COURT,
(1) By fifteen votes to one,
Finds that the Republic of Nicaragua’s claim concerning sovereignty over the northern coast
of Isla Portillos is admissible;
IN FAVOUR: President Abraham; Vice-President Yusuf; Judges Owada, Tomka, Bennouna,
Cançado Trindade, Greenwood, Xue, Donoghue, Gaja, Sebutinde, Bhandari, Gevorgian;
Judges ad hoc Simma, Al-Khasawneh;
AGAINST: Judge Robinson;
(2) By fourteen votes to two,
Finds that the Republic of Costa Rica has sovereignty over the whole northern part of
Isla Portillos, including its coast up to the point at which the right bank of the San Juan River
reaches the low-water mark of the coast of the Caribbean Sea, with the exception of
Harbor Head Lagoon and the sandbar separating it from the Caribbean Sea, sovereignty over which
appertains to Nicaragua within the boundary defined in paragraph 73 of the present Judgment;
IN FAVOUR: President Abraham; Vice-President Yusuf; Judges Owada, Tomka, Bennouna,
Cançado Trindade, Greenwood, Xue, Donoghue, Gaja, Sebutinde, Bhandari, Robinson;
Judge ad hoc Simma;
AGAINST: Judge Gevorgian; Judge ad hoc Al-Khasawneh;
(3) (a) By fourteen votes to two,
Finds that, by establishing and maintaining a military camp on Costa Rican territory, the
Republic of Nicaragua has violated the sovereignty of the Republic of Costa Rica;
IN FAVOUR: President Abraham; Vice-President Yusuf; Judges Owada, Tomka, Bennouna,
Cançado Trindade, Greenwood, Xue, Donoghue, Gaja, Sebutinde, Bhandari, Robinson;
Judge ad hoc Simma;
AGAINST: Judge Gevorgian; Judge ad hoc Al-Khasawneh;
(b) Unanimously,
Finds that the Republic of Nicaragua must remove its military camp from Costa Rican
territory;
(4) Unanimously,
Decides that the maritime boundary between the Republic of Costa Rica and the Republic of
Nicaragua in the Caribbean Sea shall follow the course set out in paragraphs 106 and 158 of the
present Judgment;
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(5) Unanimously,
Decides that the maritime boundary between the Republic of Costa Rica and the Republic of
Nicaragua in the Pacific Ocean shall follow the course set out in paragraphs 175 and 201 of the
present Judgment.
Done in English and in French, the English text being authoritative, at the Peace Palace,
The Hague, this second day of February, two thousand and eighteen, in three copies, one of which
will be placed in the archives of the Court and the others transmitted to the Government of the
Republic of Costa Rica and the Government of the Republic of Nicaragua, respectively.
(Signed) Ronny ABRAHAM,
President.
(Signed) Philippe COUVREUR,
Registrar.
Judge TOMKA appends a declaration to the Judgment of the Court; Judge XUE appends a
separate opinion to the Judgment of the Court; Judge SEBUTINDE appends a declaration to the
Judgment of the Court; Judge ROBINSON appends a separate opinion to the Judgment of the Court;
Judge GEVORGIAN appends a declaration to the Judgment of the Court; Judge ad hoc SIMMA
appends a declaration to the Judgment of the Court; Judge ad hoc AL-KHASAWNEH appends a
dissenting opinion and a declaration to the Judgment of the Court.
(Initialled) R. A.
(Initialled) Ph. C.
___________