Written reply of the Republic of Nicaragua to the question put by Judge ad hoc Gaja at the public sitting held on 16 March 2007

EMBASSY OF NICARAGUA

THE HAGUE

5 April2007

Sir,

1have the honour to refer to your letter of 29 March 2007 sent in relation to the
case concerning Maritime Delimitation between Nicaragua and Honduras in the
Caribbean Sea (Nicaragua v. Honduras), by which you inform me that the President has

granted the Honduran Government's request for a postponement of the time-limit for the
written reply ofboth Parties to Judge ad hoc Gaja's question and has fixed the new
time-limit for Thursday 5 April2007.

The question formulated by Judge Gaja to both Parties was as follows:

''MayLogwood Cay and Media Luna Cay be currently regarded as
islands within the meaning of Article 121, paragraph 1, ofthe United

Nations Convention on the Law of the Sea?''

Nicaragua gave a preliminary reply to this question during the public sitting held
on 19 March 2007. Nicaragua's answer at that point was ·asfollows:

''63.n accordance with information presently available to the
Government of Nicaragua, the cays of Logwood and Media Luna are
now submerged and cannot be regarded as islands within the meaning of
Article 121, paragraph 1, of the United Nations Convention on the Law

of the Sea

64. This information coïncides with the statement made by the
Government of Honduras in its Counter-Memorial. In it Honduras stated

that ''theoriginal Logwood Cay and Media Luna Cay are both now
submerged"(CMH, Vol. 1, p. 14, par. 2.3, footnote 2)."

Honduras for her part, during the public sitting held on 22 March 2007, addressed Judge
Gaja's question by referring to certain charts and also by using a new satellite image
(PS3.7) for the first time in this second round of oral pleadings in an attempt to demonstrate
that these cays were islands. Pointing to the image referred to as PS3.7, Honduran Counsel

stated:

"'Thatis the Arrecifes and on the very southem tip of that reef you see a
white spot, and that is Cayo Palo de Campeche, as shown on the British
chart.So this image of January 2003 is consistent with the latest United

1 EMBASSY OF NICARAGUA
THE HAGUE

Kingdom and United States charts that show Media Luna Cay and Cayo
Palo de Campeche (Logwood Cay) as islands. The answer to the
question, therefore, appears to be that both features were above water

when this satellite image was taken, and they were not, at least at that
moment, submerged."( CR 2007/13, p. 45 par. 21)

Although the imagery is in the public domain, or canbe easily purchased from data

suppliers, the processing and interpretation of such data requires specialist knowledge and
computer software and is thus not publicly available. This late submissionof evidence by
Honduras has prompted careful analysis by Nicaragua. Nicaragua has severa! satellite
scenes that cover the cays taken at different times. However, so as not to confuse the Court

further, the technical advisers of Nicaragua, the UK Hydrographie Office, purchased the
identical image to that used by Honduras and carried out a detailed interpretation in order to
evaluate the graphies presented by Honduras.

The opinion of the technical advisers ofNicaragua is appended to this letter together

with the 14 graphies to which reference is made by them. Enclosed are also 17 additional
copies of this material.

Sorne general observations are prompted by this analysis:

1. The satellite image used by Honduras cannot be used to distinguish if a reef is above

water or up to 20 meters below water.

2. The keys are in closer proximity to the Nicaraguan mainland based on the information
deduced from the satellite image produced by Honduras (see figure 4 of the annexed

graphies and paragraph 9 of the opinion appended to this letter). Honduras is seemingly
unaware of this fact as well as of the general situation of the area in dispute including
the small cays and other features.

3. The largest scale chart of the area, Chart BA2425, relied upon by Honduras and

Nicaragua is based on old surveys and shows both Logwood and Media Luna Cays as
islands. These cays have been shown unchanged since the fust edition of the chart
produced from data gathered in the original surveys conducted from 1830 and 1843.
Recent field evidence put forward by Honduras herself in her Counter Memorial (p.14,

footnote 2) suggests that they no longer exist and should have been removed from the
chart.

4. It is also revealing that Honduras, which has introduced various elements of proof
concerning other cays in the area, has not offered any document capable of establishing

the existenceofboth features as islands. This is ail the more revealing that Logwood, if
assimilated with Palo de Campeche, is the only maritime feature mentioned in the
Honduran Constitution before 1982. Had these features still existed as islands, there can

2 EMBASSY OF NICARAGUA
THE HAGUE

be no doubt that Honduras would have introduced photographs and other elements of
proof to that effect, as it did for four cays in the area.

5. In accordance with UNCLOS Article 5, charted features have been used to define a

territorial sea baseline that was used to construct a provisional equidistance line. Such
use of features charted on nautical charts is not conclusive proof of their actual
existence, which would require a hydrographical survey.

6. The absence of any indication of dry land on the infra-red satellite imagery, including
that presented by Honduras during the second round of the oral pleadings, indicates that

Logwood and Media Luna Cays are most unlikely to existas islands above water,
especially above high tide as is required byCLOS article 121.1. This lack of any
indication of dry land on the infra-red satellite imagery is also applicable to the other
small cays in the vicinity of Logwood and Media Luna Cays indicated on chart BA

2425, and therefore these cannot be regarded as islands under UNCLOS Article 121,
par.l.

In conclusion. the answer ofNicaragua to the question by Judge Gaja is that Logwood
and Media Luna Cays cannot be currently regarded as islands within the meaning of Article
121. par. 1 of the United Nations Convention on the Law of the Sea.

Accept, Sir, the assurancesf my highest consideration.

Carlos J. Argüello G6mez
Agent
Republic ofNicaragua

His Excellency
Mr. Philippe Couvreur
Registrar
International Court of Justice

Peace Palace
The Hague

3 EMBASSY OF NICARAGUA

THE HAGUE

Appendix of the opinion of the technical advisers of Nicaragua on the Question
concerning Logwood and Media Luna Cays
4 April2007

Question from Judge Gaja:

"May Logwood Cay and Media Luna Cay be currently regarded as islands

within the meaning of Article 121, paragraph 1, of the United Nations
Convention on the Law of the Sea?"

1. This answer is based on the assumption that Logwood and Media Luna Cays are those

as marked on the Admiralty chart 2425.

2. The comments here review the data shown on the chart, and information available from
satellite imagery, including the data in the graphies shown by Honduras during the
second round of oral pleadings and identified as PS3 7.2 and PS3 7.3.

Chart data

3. Nicaragua has relied upon data shown on the current edition ofBA2425. This is the
largest scale chart (1:144,000) ofthe area and thus according to UNCLOS Article 5

defines the normal territorial sea baseline. This chart shows both the position and name
of Logwood and Media Luna Cays. It also shows a very large number of other small
cays and drying reefs in the general areaf the dispute. Chart 2425 was produced from
data gathered during the original surveys from 1830 to 1843. A new edition was

produced on 29 June 1917 and a large correction was added on 23 August 1929 in
which data from US Government surveys in 1927 were incorporated into the chart.
From that date, there have been no new editions of the chart and the chart image shows
a continuous record of 31 small corrections since that date. Small corrections are

alterations to a chart that can be achieved by hand or by the addition of a small block
that can be glued in place by the user. Such corrections are clearly incorporated into the
base record of the chart as they arise, so reprints of the chart to meet market demand are
correct, but the corrections remain recorded on the chart for the life of that edition of the

chart so that a complete history of the information displayed on the chart can always be
determined. Small corrections of the sort that are recorded in the bottom left margin of
the chart are generated by local maritime authorities, local surveys and from notices
raised by mariners navigating in the area, or comprise the additionf cautionary notes

1 EMBASSY OF NICARAGUA

THE HAGUE

4. to the chart 1• On receipt of data suggesting a correction to the chart, checks on the

validity of the information and impact on navigational safety are conducted by
hydrographie experts before the datais added to the chart. None ofthese corrections
affects the cays in question and they have been plotted in the same positions for over a

hundred years.

5. In accordance with the provisions ofUNCLOS Article 5, 13 and 15 ali features with a

charted low waterline that are shown as islets or cays and ali features within 12M of the
coast or islands that are shown with a charted low waterline as low tide elevations have
been accepted at face value from the current edition of the large scale chart of the area

and treated as features providing acceptable base points for the purpose of calculating a
provisional median line.

6. There has been evidence heard that sorne of the cays among the group generally

described in proceedings as the disputed islands, may not now exist. The fact that
features thought no longer to exist remain clearly marked on a current UKHO chart is

not at ali surprising. The removal or addition of any feature from a chart is not
undertaken lightly and no such action will be contemplated without the supporting
evidence of a rigorous hydrographie survey. In the case of the cays in question, their

disappearance from view as drying islets makes little or no difference to the presence of
reefs on which they rest and, so, little difference to the safety of navigation in the area.
It is thus unlikely that an expensive hydrographie survey will be mounted to show the

features no longer exist.
Satellite lmagery

7. Honduras' two graphics show the same data at different scales but show the same

information. The data have been processed using the visible bands of the satellite. As
can be seen they give an excellent view of the reefs and other features in the area
because the data penetrate water up to a maximum depth of about 20m. These images

do not distinguish between areas above water and totally submerged reefs. It is not
clear how Honduras Counsel reached the conclusion that these features "were above
water when this satellite image was taken".

1For example the latest correction to BA2425 can be got from the website:
http:/www.nmwebsearch.com/
To accompany Notice to Mariners 5058/2006
On Chart 2425
CAUTION:SATELLITE-DERIVEDPOSITIONS
PositionsobtainedfromGlobalNavigationSatelliteSystems,suchasGPS,arenormallyreferredto WGS84Datum.Thedifferences
betweensatellite-derivedpositionsandpositionsonthis chartcannotbe deterrnined;marinersarewarnedthatthesedifferences
MAYBESIGNIFICANTTONAVIGATIONand aretherefore advisedto use alternativemethodsofobtainingpositional
2nformation,particularlywhennavigatingcloseto the shoreor inthe vicinityof dangers.
PS3 7.2; PS3 7.3.

2 EMBASSY OF NICARAGUA
THE HAGUE

8. If one looks closely at Bobel Cay on PS3 7.2 one can see a small black spot which is the
cay itself; the white area is ali underwater. As they stand these illustrations do not
indicate which are islands.

9. The two graphies presented by Honduras are based on a Landsat ETM scene acquired
on 12 January 2003, at 09:41local time (15:41 GMT). Ail Landsat scenes are acquired
at the same local time so there is no opportunity to acquire data at the low tides required

to define the low water line. Analysis of the tidal data at the time ofLandsat acquisition
using the Admiralty Total Tide programme (Figure 3) shows that the tide at that time
and date was about 0.2m above chart datum measured at Cape Gracias a Dios, the

nearest tidal reference station. Mean Higher High Water is 0.5m above chart datum for
this location, which is the level used to define dryand- or islands under Article 12111
of UNCLOS. The cays in question (Media Luna and Logwood) are less than 30M from
Cape Gracias a Dios, the closest point on the Nicaraguan mainland (Media Luna is

about 25.8M and Logwood about 27.5M; the closest, Bobel, is about 26.5M- Figure 4).
The tidal range at the cays is therefore likely to similar or less than that at Cabo
Gracias a Dios though no detailed tidal information is available.

10. Careful processing of the raw satellite data can provide much useful information.
Honduras have used only the visible wavelengths which penetrate up to 20m ofwater.
Landsat also contains severa! infra-red bands. These have zero penetration of water so
can be used to distinguish between those areas above and those below water.

11. Figure 5 shows the same area as PS3 7.1 and has been processed in a similar way. Use
of the visible wavelengths has produced a realistic true-colour picture that shows
considerable detail of the shape and nature of the reefs. Figure 6 shows the same area

but using the infra-red band 7 only. It is clear that the submerged reefis no longer
visible. Clouds and their shadows can still be seen as can, even at this scale, the cays at
Bobel, Port Royal, Savanna, and South. Scattered small clouds, as seen in the north of
this scene, can make the positive identification of cays difficult. Without careful

analysis, this can result in clouds being mistakenly iderttified as "false" cays but will not
lead to genuine cays or islands being missed.
The same analysis ofPS3 7.2 can be seen in Figures 7 and 8.

12. As these figures are rather too small scale to see detail, enlargementsof each of the cays
has been done. The imagery used has a resolution of 30m- that is the image is
composed of"pixels" each ofwhich is 30m square. Much smaller features however
will be identifiable if they have high contrast - that is a small but bright rock above

water will influence the average brightness of that pixel. The images are a little blurry

3http://www.ukho.gov.uk/amd/TotalTideSDK.asp

3 EMBASSY OF NICARAGUA

THE HAGUE

because of the high degree of enlargement - but this does not affect the information

presented.

13. Figure 9 shows a comparison of the visible and infrared processing for Logwood Cay as
identified by Honduras in PS3 7.1. This cay is also shown on the chart BA2425 but due
to inaccuracies in the chart is plotted approximately 1km to the northeast of the satellite­

derived position. (This is consistent with warnings about positionsn the chart.). The
left-hand (visible) image shows the detail of the submerged reefs in the area. The
brighter areas in general are shallower, and this can be used as a qualitative measure of
water depth. The right hand image shows the infra-red band (Band 7 ofLandsat). This

band has no water penetration so can be used to distinguish areas above and below
water. Nothing can be seen on this image. On this basis there is no part of Logwood
Cay that is above water at the time of this satellite image. As the tide at the time this
image was acguired was not a high tide (see para 9 above), no partofLogwood Cay can

thus be considered an island.

14. The same analysis has been done for HalfMoon/Media Luna Cay. Figure 10 shows the
extent of the submerged reef- over a mile long. However, based on the infrared data,
no partof this can be considered to be above water - not even at the relatively low tide

at the time of satellite data acquisition. The chart shows a larger cay in the southwest
and five smaller islands. None ofthese appears on the infrared imagery.

15. As a contrast, and to confirm the methodology used, the same processing has been

carried out for the four cays whose existence is not in doubt. Figures1 to 14 show the
analysis of the cays- Bobel, Port Royal, Savanna and South (Sur). These cays are
clearly visible above water on the infrared data; the submerged cays are not. The data
are less clear for Port Royal (Figure 12) where cloud has obscured part of the cays.

16. This analysis effectively disproves the presenceof land above water at Logwood and
Media Luna Cays, and hence their status as islands.

Conclusion

17. Logwood and Media Luna Cays can not be regarded as islands under UNCLOS Article
121. paragraph 1.

4••

• • •

Tides at Cape Gracias a Dios

15.00'N,93•11'W 12/01/200302:04 0.2m
Predicarebasedon PORT0FSPAlN

~ Grap+J .WLW1~ Heig1ls

0.5tTidalHeight(Metres)

0.4

0.3

021:.---~
_j~ GraciADios
"J.·m04:26 +0600 0.1

0.01 1 1 11 1 1 1 1 1
00:0003:0006:0009:00 12:0015:0018:0021:0000:00
12/01/2003 13/01/2003
109:40 0.2 m1
Noclearanceheightsordepthshavebeenset
Differspprol!imate.
PredictedheightsareinmetresaboveChartDatum

U 1 CloseIll Cance1.·..-- ~,.-

Tide at time of satellite
image = 0.2m above
chart datum
~

Screen dump from Admiralty Total Tide: a global tidal
prediction programme for the area of Cape Gracias a
Dios for 12 January 2003..

Figure3 • •
Proximity of Cays to Cape Gracias a Dios -

the nearest tidal prediction station 82°30'

..,., Media Luna
.~T\IR~eefs
-~•-.•..'
Logwood . ~ " ,_..~.,
Media Lun1 ' '.. :.,f\ Alagardo
Port , . Savanna Reefs
Royal
,, ' South

15o..J, ..... -· ~15°

• cockRocks

Edinburgh
·rReefs
Edinburgh C"-1

10 20M

83
Figure 4 •

Regionalviewofcays

15~15'
15 '15"

15.0'
15°10

15'5' 155'

Visibleand processing. Water penetration is about 20m.
Detailsf the submerged reefs can be seen. Note also
scattered clouds and their shadows, especially in the north.

Band cotnbinntion: 321-RGB
0 2 a 10
15" 15
82--40' 82
Equivalent to PS3 7.2
Figure 5 • •

Regional view of cays- infra-red

15°15"

15(10" 5°10

1s~s·
55'

Band 7( btfrared)only Infra-red processing. There is no water penetration sono
subsurface features are visible. Islands however can be
0 2 4 6 6 10M
15'1' :- bwl' L1 1 1 1 l , • seen,1though small at this1scale. Clouds are clearl~15;sible. ,
82~40' 82 35' 82'"25' 82
Figure 6 • •

Media Luna Reefs

•15"15' 5°15'

15°14' 5°14."

15"13'
5°3"

15°12'
5 12'

15°11' 5~11"

15,"10' 5~0"

Band comb1natmon321-RGB
Figure 7 • •

Media Luna Reefs- infra-red

15 15'

15 14'

15"13'

'15°1:2'

15"11'

15'10'

82-43' 82-42'
&1nd7(Infra-red)on1y Figure 8 • •
Logwood Cay

:a-30''

Band combination: 321-rgb

Visible band processing. Water penetration is about 20m.ocessing. There is no water penetration sono
Detailsthe submerged reefs can be seen. above water.eatures are visible. There are no features visible

Figure9 • •
~e unaCaya 1

10'

15

Visible band processing. Water penetration is about 20m. water penetration sono
Details of the submergeabove water.be seen.are visible. There are no features visible

Figure10 • •

1Bobel Cay 1

15

rtl~

Visible band processing. Water penetration is abousubsurface features are visible. The cay is clearly visible
area corresponds to vegetation.can be seen. The daabove water.

Figure 11 • •

PortRoyalCays

1S

n.1tl4Ji:)ll•<mIIJ·Qtl

Visible band processing. Water penetration is about 20m.fra-red processing. There is no water penetration sono
Details of the submerged reefs can be seen. Partly obscuredrface features are visible. The cays are clearly visible
by cloud. above water. Partly obscured by cloud.

Figure 12 • •

1Savanna Cay 1

Visible band processing. Water penetratisubsurface features are visible. The cay is clearly visible
Details of the submerged reefs can be seabove water.
Figure13 • •

1 South (Sur) Cay 1

1S 16"_'30' 5"30'

15."5' s

15'4'30'

l~n~œ:ninntJiJonOU Band.7(lnfr.a·n:d) un1)•

Infra-red processing. There is no water penetration sono
Visible band processing. Water penetration is about 20m. subsurface features are visible. The cay is clearly visible
Details of the submerged reefs can be seen. above water.

Figure14