Offshore Magazine - December 2017

Special Chamber Ruling
Ghana – Cote d’Ivoire Maritime Boundary (MB)

Segment “A” – MB “East” of Ghana Claimed Line
Segment “B” – MB “West” of Ghana Claimed Line
Segment “C” – MB “East” of Ghana Claimed Line
Black dashed line is final MB.

Black circles are Special Chamber turning points.

Red circles are Ghana’s claimed turning points.

Red stars are MB line(s) “cross-over” positions.

Orange dashed line is Ghana’s claimed line.

Blue dashed line is Cote d’Ivoire’s claimed line.

Green dashed line(s) claimed extended continental shelf.

Scale: 1:300,000 Scale: 1:300,000

Scale: 1: 1,800,000

Area “A”
Segment “A”
Area “B”
Area “C”
Segment “B”
Segment “C”
Segment “A” Length 29. 65 NM
Area is 17.85 km2 (Geodetic)

Segment “B” Length 164.13 NM Area is 120.34 km2 (Geodetic)

Segment “C” Length 50.96 NM Area is 20. 55 km2 (Geodetic)

Having found that delimitation of the area of overlapping claims could be satisfactorily accomplished by constructing a provisional equidistance line, the Special Chamber identified a starting point and selected base points for the line that differed from those advanced by both parties. Given that the agreed border post 55 is situated some 150 m from the low-water line, the Special Chamber, guided by the parties’ coastline, fixed the starting point, referring to it as “BP55+.” It did so by extending the direction of the land boundary from border post 54 to BP55 until it reaches the low-water line.

After identifying base points by re-dig- itizing the relevant coastline reflected on British Admiralty Chart 1383, which dates back to the 19th century, the Special Chamber reduced the resulting high number of base points by using, for each party, only those points furthest from and nearest to the land boundary terminus and the points in the middle, yielding five base points for each country. 13

The resulting boundary, which starts from
BP55+, includes six turning points at which
the direction of the line changes and which
are connected by geodetic lines. From the
southern-most turning point, the equidis-
tance boundary continues as a geodetic line
starting at an azimuth of 191° 38’ 06.7” until
it reaches the outer limits of the continental
shelf beyond 200 nautical mi. 14

As regards the course of the line delimiting the continental shelf beyond 200 nautical mi, which it confirmed could be fixed by it, the Special Chamber emphasized that “there is in law only a single continental shelf.” 15 Without fixing a termination point, it found that this segment of the boundary runs in the same direction as the line within 200 nautical mi.

Given that the boundary line thus fixed by the Special Chamber begins south and east of border post 55 agreed upon by both parties (i.e., commences at a new starting point) and has its own six turning points, plus its own azimuth, for the remainder of the single line, the final boundary does not coincide with the equidistance line claimed by Ghana. The final line starts out east of Ghana’s claimed line, crosses to the west (offshore) and then crosses again east nearing the 200-nautical- mile EEZ limit, before continuing to the extent of the continental shelf.

The Special Chamber rejected all of the
parties’ arguments that an adjustment or
shifting of the provisional equidistance line
was required in the present case based on
“relevant circumstances” and found instead
that strict application of the equidistance
method resulted in an equitable solution in
this case. The Special Chamber also deter-
mined that the line constructed by it “does
not lead to an inequitable result owing to a
marked disproportion between the ratio of
the respective coastal lengths [here, 1: 2. 53]
and the ratio of the relevant maritime area
allocated to each Party [here, 1: 2.02].” 16

Finally, the Special Chamber rejected, for lack of convincing evidence, all of Côte d’Ivoire’s arguments regarding Ghana’s in- ternational responsibility based on allegedly unlawful conduct by Ghana both prior and during the proceedings. 17

Concluding observations

Maritime boundary cases often involve, and are triggered by, competing claims to nat- ural resources, and this case is a prime example. The Special Chamber’s ruling, which is not open to appeal, affirms the cautious treat- ment that international courts and tribunals generally have given to non-geographical, resource-related criteria when considering relevant circumstances that might justify ad- justing or shifting a provisional equidistance line in cases where drawing such a line is feasible. According to the Special Chamber, “a de facto line or modus vivendi related to oil practice [of the disputing coastal States]