A. Legal bases for Ghana’s claims

• 107. At the outset, the Special Chamber considers it necessary to clarify a few preliminary points related to the legal bases for Ghana’s claim of the “customary equidistance boundary”.

• 108. Côte d’Ivoire argues that Ghana’s claims suffer from considerable terminological confusion by combining “agreement” and “custom” as in an expression “Parties’ Agreement on the Customary Equidistance Boundary” and that this is simply a reflection of Ghana’s uncertainties over the legal bases of its claims. According to Côte d’Ivoire, by using the expression “customary equidistance boundary”, Ghana appears to seek the application of the theory of bilateral custom, but provides evidence of neither the material element of custom nor its psychological element. In light of this circumstance, Côte d’Ivoire is compelled to assume that it is a tacit agreement that constitutes the main foundation of Ghana’s claim. However, Côte d’Ivoire points out that the notion of “customary equidistance boundary” has no basis in international law and that the use of this expression adds nothing to Ghana’s tacit agreement argument except confusion.

• 109. Côte d’Ivoire also points to Ghana’s silence over the nature and scope of the alleged tacit agreement. For Côte d’Ivoire, where a State invokes the existence of an agreement, whether “express or tacit”, on delimitation, it must prove that such an agreement is established for each of the maritime areas claimed on that basis and to their entire geographical extent. Côte d’Ivoire contends that Ghana likewise must provide proof that the purported agreement is applicable to the maritime areas claimed in their entirety. However, according to Côte d’Ivoire, Ghana fails in this regard because Ghana’ argument for a tacit agreement is based solely on the oil concession practice of the Parties, which, even if accepted, cannot extend to the waters superjacent to the seabed. Nor can it extend as far as its boundary claims, as Ghana’s oil concessions run at most to an approximate distance of 87 nm from the land boundary terminus, which is less than half of the length of the boundary line [Page 433] claimed by Ghana, and its actual petroleum activity runs to even less, at only 54.5 nm from the land boundary terminus. Côte d’Ivoire asserts that in any event Ghana fails to prove that its oil practice constitutes an agreement on delimitation even in respect of the continental shelf.

• 110. Ghana maintains that its reference to “customary” maritime boundary reflects “the existence of a specific boundary line that both Parties have recognised and respected over the course of more than five decades by their mutual, sustained, and consistent conduct”. According to Ghana, it “has never argued that this ‘customary equidistance line’ reflects a bilateral custom”. Ghana explains that this term simply refers to the fact that both Parties have over time mutually followed an equidistance line in their practice. Ghana submits that the customary line is a reflection of the Parties’ tacit agreement as to the existence of a maritime boundary following an equidistance line, as distinguished from a formal boundary treaty.

• 111. Ghana contends that a tacit agreement that has emerged between the Parties on a common maritime boundary was the result of their mutual, consistent recognition and acceptance of such a boundary over many decades. For Ghana, the limits of the Parties’ oil concessions are a reflection of, and based on, a “pre-existing” maritime boundary as mutually agreed and recognized by them. Ghana further submits that a tacit agreement on the boundary exists with respect to the entire maritime zone subject to these proceedings, namely the territorial sea, the exclusive economic zone and the continental shelf both within and beyond 200 nm, as is shown by the evidence it presented before the Special Chamber.

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• 112. In light of the above, the Special Chamber understands that Ghana’s claim for the delimitation of the territorial sea, exclusive economic zone and continental shelf within and beyond 200 nm is based on a tacit agreement which has been developed or confirmed as a result of the oil activities of both Parties over years. Having identified the legal basis, nature and scope of Ghana’s claim, the Special Chamber must now ascertain whether a tacit agreement exists, as Ghana argues and which Côte d’Ivoire challenges.

B. Oil activities

• 113. Ghana maintains that the tacit agreement on the location of the customary equidistance boundary is most clearly reflected in the [Page 434] consistent “oil practice” of both Parties for more than five decades. According to Ghana, such oil practice includes, inter alia, oil concessions, seismic surveys, and exploration and drilling activities. Ghana contends that “the oil and gas activities carried out by, or under licence from Ghana” have been in areas that fall on the Ghanaian side of that boundary, whereas similar Ivorian activities have been confined to the west of that boundary. Ghana further asserts that neither Party has ever protested, or objected to, any of these activities by the other.

• 114. Côte d’Ivoire contends that oil practice cannot establish a tacit agreement on “an all-purpose international maritime boundary between States”. Côte d’Ivoire argues that international courts and tribunals have been reluctant to treat oil practice as proof of the existence of a maritime boundary. For Côte d’Ivoire, oil practice says nothing about any of the other sovereign rights, jurisdiction and duties of the coastal State in the exclusive economic zone and on the continental shelf. Moreover, Côte d’Ivoire argues that the oil practice upon which Ghana relies is not only “equivocal” but is contradicted by the conduct of Côte d’Ivoire, and of Ghana itself.

C. Legislation of the Parties

• 151. Ghana maintains that the Parties’ recognition of the primacy of equidistance for delimiting a maritime boundary as well as their acceptance of an equidistance-based boundary is explicitly referenced in their legislation.

• 152. Ghana first refers to the Decree of 29 July 1957 issued on behalf of what was then the colony of Côte d’Ivoire by the President of the Council of Ministers in France. For Ghana, the decree is the first example of legislation which acknowledged the existence of the equidistance-based maritime boundary between the Parties dividing their respective territorial seas.

• 153. Ghana further refers to Presidential Decree 70–618 of Côte d’Ivoire issued on 14 October 1970. This decree was issued by President Houphouët-Boigny to authorize a concession agreement with a consortium led by Esso. The decree explicitly states that the boundary of the Esso concession in the east is “the border line separating the Ivory Coast from Ghana between points K and L”. According to Ghana, points K and L depict an equidistance line. Ghana contends that the issuance of decree 70–618, signed by the President, constitutes “an explicit and unambiguous recognition by Côte d’Ivoire’s Head of State of the existence of a maritime border between Ghana and Côte d’Ivoire that follows an equidistance line”.

• 154. Ghana also draws the Special Chamber’s attention to article 8 of Law 77–926 on Delimiting the Maritime Zones placed under the National Jurisdiction of the Republic of the Côte d’Ivoire of 17 November 1977 (hereinafter “the 1977 Law”), which provides that:

  With respect to adjoining coastal States, the territorial sea and the zone referred to in Article 2 of this law [i.e., the exclusive economic zone] shall be delimited by agreement in conformity with equitable principles and using, [Page 444] if necessary, the median line or the equidistance line, taking all pertinent factors into account.

• 155. Ghana claims that article 8 “officially recognized the principle of equidistance as the most appropriate method of delimitation of Côte d’Ivoire’s maritime boundaries”, which can be “recognized as offering an equitable solution with respect to its maritime boundary with Ghana”. Ghana notes that the 1977 Law remains in effect and applicable to this day and that its content has been reaffirmed in other national legislation, including with respect to fishing and navigation, and petroleum.

• 156. For its own legislation, Ghana notes that article 4 of its Law on Petroleum Exploration and Production of 1 June 1984 (hereinafter “the 1984 Petroleum Law”) provides that Ghana’s concession maps show the petroleum fields “within the jurisdiction of Ghana”. Ghana points out that its official charts and concession maps consistently show Ghana’s exclusive economic zone and continental shelf as “being delimited by the customary equidistance boundary”. Ghana further points to Section 7 of the Maritime Zones (Delimitation) Law of 2 August 1986, which provides that “[t]he lines of delimitation of the territorial sea, exclusive economic zone and continental shelf as drawn on official charts are conclusive evidence of the limits of the territorial sea, exclusive economic zone and continental shelf”.

• 157. For its part, Côte d’Ivoire submits that “a country’s legislation cannot under any circumstances establish the existence of an agreement between two States”. According to Côte d’Ivoire, a law may confirm an agreement but it cannot create it.

• 158. Côte d’Ivoire contends that Ghana’s explanation of the origin of the alleged tacit agreement in a 1957 decree issued in Paris by the then French colonial power is “hardly convincing”. For Côte d’Ivoire, it cannot seriously be argued that the 1957 decree establishes that the eastern limit of the concession, which was not even mentioned in the decree, followed an equidistance boundary.

• 159. Côte d’Ivoire notes that Presidential Decree 70–618 of 14 October 1970, to which Ghana attaches considerable significance as evidence of Côte d’Ivoire’s recognition of the alleged customary equidistance boundary, does not contain any reference to such a boundary or to any other recognized boundary. According to Côte d’Ivoire, its only purpose is the organization by Côte d’Ivoire of exploration of its oil reserves. Côte d’Ivoire argues that Ghana distorts the wording of the decree by deliberately ignoring the fact that the Decree distinguishes between points whose coordinates are given specifically [Page 445] and other points (such as points K and L) whose coordinates are “approximate”. According to Côte d’Ivoire, this cautious wording reflects the uncertainty and the lack of agreement over its maritime boundaries. Côte d’Ivoire also notes that article 1 of the decree uses identical terms to describe the eastern limits of Côte d’Ivoire with Ghana and the western limits with Liberia. It states that “[t]o accept Ghana’s position seeking to establish a new maritime boundary with Côte d’Ivoire, claiming a long-term agreement, would therefore effectively lead the Special Chamber to establish a new boundary” between Côte d’Ivoire and Liberia. In Côte d’Ivoire’s view, such position cannot be legitimately upheld.

• 160. In this regard, Côte d’Ivoire draws the Special Chamber’s attention to decree 75–769 of 29 October 1975, which renewed the hydrocarbon exploration permit granted to the consortium led by Esso in 1970. Article 2 of the decree contained the following reservation: “The coordinates of reference points M, L and K separating Côte d’Ivoire and Ghana are given by way of indication and cannot in any case be considered as being the national jurisdiction boundaries of Côte d’Ivoire”. Côte d’Ivoire claims that “article [2] of the Decree makes clear that the limits of the concession certainly do not represent the maritime boundaries of Côte d’Ivoire”.

• 161. As for its 1977 Law, Côte d’Ivoire asserts that Ghana’s reading of article 8 is incorrect. According to Côte d’Ivoire, article 8 provides that the maritime boundaries of Côte d’Ivoire must be delimited “by agreement in conformity with equitable principles”, using “if necessary”, the equidistance/relevant circumstances method. In Côte d’Ivoire’s view, it is clear from the wording of article 8 that the use of the equidistance or median line is only relevant “if necessary”—“le cas échéant”—meaning that the use of such line will depend on the circumstances of the case. It thus simply reflects the state of the law on maritime delimitation as it stood.

• 162. Côte d’Ivoire argues that Ghana’s “1986 Maritime Zones (Delimitation) Law” offers no assistance as it refers to official charts representing maritime boundaries and these have never been produced. Even if they had been, they would only have represented Ghana’s position and not an agreement between the Parties.

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• 163. The Special Chamber observes that national legislation, as a unilateral act of a State, is of limited relevance to proving the existence of an agreed maritime boundary. In the present case, the legislation of [Page 446] both Parties adduced by Ghana does not give a clear enough indication in that respect. The decree of 1957 dealt with a concession on oil activities, not with the establishment of a boundary in the territorial sea. Similarly, decree 70–618 issued by the President of Côte d’Ivoire establishes a boundary for the Esso concession. The reference to the “border line separating the Ivory Coast from Ghana between points K and L” cannot be taken as the acknowledgement of a tacit agreement between the two States that a maritime boundary exists. This interpretation of decree 70–618 is confirmed by Côte d’Ivoire’s decree 75–769, which renewed the hydrocarbon exploration permit granted to a consortium led by Esso, where it is explicitly stated that “[t]he coordinates of reference points M, L and K separating Côte d’Ivoire and Ghana … cannot … be considered as being the national jurisdiction boundaries of Côte d’Ivoire”. This decree actually proves exactly the opposite of what Ghana claims. Finally, article 8 of the 1977 Law of Côte d’Ivoire mentions a future delimitation (“shall be delimited by agreement”) and therefore, once again, cannot be used to prove that a tacit delimitation agreement already existed.

D. Representation to international institutions

• 164. Ghana argues that both Parties have accepted the customary equidistance line as an international boundary in their statements to international institutions, in particular the Commission on the Limits of the Continental Shelf (hereinafter “CLCS”). In this regard, Ghana draws the attention of the Special Chamber to the submissions of the two Parties to the CLCS. According to Ghana, Côte d’Ivoire’s submission “asserted a claim beyond 200 miles only to the west of an equidistance boundary with Ghana” and Ghana’s submission likewise “asserted a claim only to the east of the equidistance boundary”. In Ghana’s view, this shows that “both Parties appear to have accepted that the customary equidistance line … extends beyond 200 M, to the full extent of their maritime entitlements, including the outer continental shelf”.

• 165. Ghana further points to the revised submission made by Côte d’Ivoire on 24 March 2016, “less than a fortnight prior to filing its Counter-Memorial”, which replaced its original submission. Ghana notes that, as a result of this “new and enlarged submission”, “the entitlements of Ghana and Côte d’Ivoire in the outer continental shelf are now said to overlap, whereas previously there was no overlap”. However, Ghana argues that “such a revised submission, coming [Page 447] several years after the commencement of the dispute can be of little probative value for the Special Chamber in assessing the existence of a tacit agreement between the Parties and determining an equitable maritime boundary”.

• 166. Côte d’Ivoire rejects Ghana’s argument, stating that its original submission of 8 May 2009 to the CLCS does not constitute acceptance of the alleged customary equidistance line. Côte d’Ivoire recalls that its submission to the CLCS of 8 May 2009 expressly stated that “Côte d’Ivoire has overlapping maritime claims with adjacent States in the region, but has not signed any maritime boundary delimitation agreements with any of its neighbouring States to date”. The submission also indicated that the consideration of the Ivorian submission “will not prejudice matters relating to the determination of boundaries between Côte d’Ivoire and any other State(s)”. Côte d’Ivoire points out that the same position was stated in Ghana’s submission to the CLCS of 28 April 2009. In the view of Côte d’Ivoire, Ghana’s argument that Côte d’Ivoire’s 2009 submission constitutes an official statement that “show[s] clearly its acceptance of the customary equidistance boundary” is therefore unfounded. On the contrary, it is clear on reading the submissions lodged by both Parties in 2009 that there is no agreement on the maritime boundary between them.

• 167. As regards its amended submission of 24 March 2016, Côte d’Ivoire explains that its original submission in 2009 did not fully document the entitlement to an extended continental shelf, both to the east and to the west and that in 2016 it became urgent for Côte d’Ivoire to provide the CLCS with all the information required for it to assess the extent of Côte d’Ivoire’s entitlement, “as its submission was next in line as queued by the Commission in the order received”. Côte d’Ivoire also points out that it is not in any way invoking this amended submission in support of its arguments concerning the maritime boundary with Ghana. According to Côte d’Ivoire, it is doing so “solely in order to provide proof of its entitlement to the continental shelf beyond 200 nautical miles and the extent thereof”.

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• 168. The Special Chamber notes that the submissions to the CLCS of both Parties clearly indicate the existence of overlapping maritime claims with neighbouring States and include a disclaimer that their consideration will be without prejudice to the determination of each Party’s lateral maritime boundaries. In light of this clear indication, in the Special Chamber’s view, the fact that the limits of the continental [Page 448] shelf claimed by the two Parties in their initial submissions coincide along the equidistance line can hardly be considered as evidence of a tacit agreement on a maritime boundary. The amended submission of Côte d’Ivoire, which the Special Chamber will later examine to ascertain whether it can be taken into account in these proceedings, does in fact support this finding.

E. Bilateral exchanges and negotiations

• 169. Côte d’Ivoire maintains that “[t]he most important element of conduct pointing to the absence of a tacit agreement” is that the Parties repeatedly proposed negotiations on the delimitation of a maritime boundary and such negotiations eventually took place. According to Côte d’Ivoire, bilateral exchanges and negotiations between the Parties between 1988 and 2014, and their failure, are the very proof of the fundamental disagreement between the Parties on their maritime boundary.

• 170. Côte d’Ivoire recalls that, before the 15th ordinary session of the Joint Commission on Redemarcation of the Ghanaian-Ivorian Border (“Commission on Redemarcation”), it requested that the “delimitation of the maritime and lagoon boundary” be included in the agenda and Ghana agreed to it. Côte d’Ivoire further recalls that at the meeting it proposed “a maritime boundary line consisting in extending seaward the terminus segment of the land boundary between posts 54 and 55”. According to Côte d’Ivoire, at the meeting Ghana did not respond to the Ivorian proposal not because a maritime boundary had already been delimited but for the reason that it had no mandate to discuss it. Côte d’Ivoire asserts that this exchange shows that from 1988 it has made clear to Ghana that it considered no agreement on delimitation to exist between the Parties, that it wished to conclude such an agreement by way of bilateral negotiations, and that it claimed a maritime boundary distinct from the so-called “customary line”.

• 171. According to Côte d’Ivoire, four years later, in February 1992, Ghana proposed to it that the question of maritime delimitation be dealt with bilaterally. Following considerable preparatory work, Côte d’Ivoire replied in April 1992, accepting its invitation to negotiate. On that occasion, Côte d’Ivoire notes that it made a request to Ghana by a telegram to the effect that “whilst awaiting the meeting of the Joint Border Redemarcation Commission, the two countries shall abstain from all operations or drilling works in the Zone whose status remains [Page 449] to be determined”. Côte d’Ivoire states that Ghana never responded to the Ivorian request and the meeting did not take place. However, in the view of Côte d’Ivoire, Ghana’s proposal to initiate maritime negotiations suggested that it considered that no tacit agreement on delimitation existed between the Parties.

• 172. Côte d’Ivoire adds that on 2 December 1997 the Parties held a meeting of technical working teams where it was agreed, according to the minutes, to “reactivat[e] the Ivoiro-Ghanaian Commission on the border problems”. Given that the demarcation of the land border had been completed by that time, this was clearly a reference to maritime delimitation negotiations.

• 173. Côte d’Ivoire states that bilateral negotiations on delimitation of the maritime boundary finally began in July 2008 and the ten meetings of the Joint Ivoiro-Ghanaian Commission of the Maritime Border Demarcation between Côte d’Ivoire and Ghana (hereinafter “the Commission on Maritime Border Demarcation”) took place, ending in May 2014. During the first meeting on 16 and 17 July 2008, according to Côte d’Ivoire, Ghana made a delimitation proposal for the first time to the effect that “the border currently used by the international oil companies and the national companies … should be formalized and recognized within the framework of a bilateral agreement as being the maritime border between the two countries”. Côte d’Ivoire argues that this is “a very explicit recognition” by Ghana of the distinction between petroleum concessions and a maritime delimitation. Côte d’Ivoire notes that in its communication of 23 February 2009 to Ghana, Côte d’Ivoire, “reiterating the position it had already set out in 1988 and 1992 to the effect that their maritime boundary could be delimited only by express agreement in accordance with UNCLOS”, rejected this proposal, stating that the proposed line which was used by the oil companies to avoid boundary disputes does not constitute an official agreement between the two States. According to Côte d’Ivoire, it instead proposed that “the boundary be delimited using the geographical meridian method”.

• 174. Côte d’Ivoire further notes that on this occasion, it reiterated its request that the Parties should refrain from any activity in the area to be delimited:

  Moreover, important exploration and evaluation works were undertaken in 1980 by Ghana in the maritime border zone between the two countries. These works are still ongoing, in spite of representations made by Côte d’Ivoire in 1988 and 1992 to Ghana requesting the latter country to stop any unilateral activity in the neighbouring maritime border until a determination by consensus of the maritime border between our two coastal States. Any works [Page 450] likely to potentially undermine the interests of Côte d’Ivoire must not be undertaken.

• 175. Côte d’Ivoire states that at the fourth meeting held on 27 and 28 April 2010, Ghana reiterated “its initial proposal based on the equidistance/relevant circumstances method”. In response, Côte d’Ivoire notes that it provided more detailed observations on Ghana’s position in a communication dated 31 May 2010, in which it explained the “justifications for rejecting the equidistance method”, namely “the cut-off effect to the detriment of Côte d’Ivoire” and the “spectacular effects of amputation and enclosure” resulting from this method. Côte d’Ivoire adds that it reiterated its proposal to use the meridian method.

• 176. According to Côte d’Ivoire, Ghana, in its response dated 31 August 2011, repeated its proposal to adopt “its oil concession line as the maritime boundary on the ground, put forward for the first time, that it was supposedly an equidistance line adjusted to the east in order to follow the limit of its oil blocks, which constituted a relevant circumstance”. Côte d’Ivoire argues that Ghana, in this response, also introduced “the notion of tacit agreement into the debate for the first time, without, however, explaining its purpose, its effects or its link with the application of the equidistance method which it had just invoked”.

• 177. Côte d’Ivoire notes that at the fifth meeting held on 2 November 2011, it made “a new proposal for delimitation based on … the bisector method”. Côte d’Ivoire points out that at the meeting it also stated that “oil practice could not under any circumstances be translated to mean the existence of a tacit agreement” and “reiterated its request, which had already been made in 1992 and 2009, that oil activities in the maritime boundary area be suspended pending a bilateral delimitation agreement”. According to Côte d’Ivoire, the expression “customary equidistance boundary” seems to have been first used by Ghana during this meeting. Côte d’Ivoire adds that oil practice was no longer raised by Ghana as “constituting a tacit agreement” until the present proceedings, but merely as “a relevant circumstance justifying the modification of the strict equidistance line”.

• 178. Côte d’Ivoire states that at the tenth meeting held on 26 and 27 May 2014 it reiterated its proposal based on a bisector line which it justified on grounds of marine erosion, the concavity of the Ivorian coast and the regional specificities of the Gulf of Guinea but Ghana rejected this argument without even discussing its merits. Côte d’Ivoire further notes that at the end of the meeting the Parties concluded that a “specific method of delimitation has not yet been agreed by both parties”. According to Côte d’Ivoire, it was at this point that Ghana “suddenly unilaterally” broke off the bilateral negotiations.

• [Page 451] 179. In addition, Côte d’Ivoire draws the Special Chamber’s attention to two joint statements issued by the Presidents of the two States, the first in 2009 and the second in 2015, which reaffirmed their determination to find a negotiated settlement of the maritime boundary. The first joint statement dated 4 November 2009 states that

  the land boundary has been delimited whereas discussions aiming at the delimitation of the maritime boundary had been initiated by the two countries. The two leaders called upon the competent authorities of the two countries to proceed further with the discussions in order to reach a quick outcome.

• 180. The second joint statement of the Heads of State issued on 11 May 2015 also affirmed that “[t]he delimitation of the maritime boundary remains an objective of the Parties”. For Côte d’Ivoire, such statements, made at the highest State level, are compelling evidence of the absence of an agreement on delimitation.

• 181. Côte d’Ivoire contends that the minutes of the negotiations, the related documents and the joint statements issued on the occasion of the meetings of the two Heads of State, taken together, show, inter alia, that there was no tacit agreement on the maritime boundary between the Parties and that during the negotiations Côte d’Ivoire reiterated its request that Ghana stop its oil activities in the disputed area.

• 182. Ghana does not dispute that the issue of formalizing the maritime boundary was included in the agenda of the 1988 meeting of the Commission on Redemarcation, or that Côte d’Ivoire proposed an alternative method of delimitation to the principle of equidistance. Ghana acknowledges that the minutes of the proceedings reflect that this point was part of the agenda of the meeting and that Côte d’Ivoire made a presentation on this matter.

• 183. Ghana nonetheless notes that the report of the meeting on this matter is limited to a single paragraph and that Côte d’Ivoire offers no evidence as to the presentation it delivered in 1988. According to Ghana, if a presentation on an alternative method of delimitation had been important, it would have been reflected in the minutes of the proceedings or at least added to them later, but Côte d’Ivoire offers no such evidence in support of its claim. Ghana indicates that the fact that no further communication on the “Ivorian proposal” took place following the 1988 meeting is revealing. Ghana contends that, judging by these circumstances, Côte d’Ivoire’s raising of the issue of delimitation before the Commission on Redemarcation in 1988 was “a minor, isolated event”. Moreover, Ghana draws the Special Chamber’s attention to the fact that the minutes of the 1988 meeting [Page 452] state its objective as being to study the possibility of delimiting the maritime boundary “existing between the two countries”. For Ghana, this wording contradicts Côte d’Ivoire’s claim that there was no existing maritime boundary.

• 184. With respect to its 1992 invitation to address the issue of maritime delimitation through bilateral negotiation, Ghana rejects Côte d’Ivoire’s argument that such an invitation shows that “there was no delimitation agreement existing between the Parties at that time”. According to Ghana, the purpose of its invitation was to “formally and precisely establish what they had already accepted in practice and principle”. Ghana therefore argues that its proposal to address the question of the formal delimitation of the maritime boundary through bilateral negotiations is fully consistent with the existence of a tacit agreement on the customary equidistance line.

• 185. With respect to the 1992 telegram suggesting that, pending a planned meeting of the two States’ boundary experts, they should refrain from further activity in the border area, Ghana contends that it is an internal communication and that there is no evidence that it was ever conveyed to Ghana. Ghana further argues that “[i]f it was proposed at all, it was done tentatively and in the mildest of terms, simply expressing the hope that both States might suspend such activities”, and was far from a protest.

• 186. Ghana further maintains that in any event Côte d’Ivoire’s subsequent practice clearly contradicts the narrative it gives. Ghana points out that, with respect to its 1992 invitation, Côte d’Ivoire’s Government did not follow it up after the initial date proposed by Ghana had been refused by the authorities of Côte d’Ivoire and that as a result the Commission on Redemarcation never met again. In Ghana’s view, it is difficult to see why Côte d’Ivoire never attempted to revive Ghana’s invitation and set a new date for the meeting of the Commission on Redemarcation if there truly was a disagreement between the two States as to the course of their maritime boundary.

• 187. Ghana asserts that Côte d’Ivoire’s subsequent practice also contradicts its alleged request that both States suspend all activities in the relevant areas. According to Ghana, “for fifteen years from 1992 to 2007 Côte d’Ivoire actively participated in mutual State practice with Ghana, while being perfectly informed of Ghana’s activities”. In parallel, Ghana points out, Côte d’Ivoire developed its own activities exclusively in what have always been considered as its waters to the west of the customary equidistance boundary. Thus Ghana claims that the exchanges in 1988 and 1992 are “minor outliers, at most, in the five decades of consistent mutual practice between the Parties”.

• [Page 453] 188. With respect to the bilateral negotiations on the delimitation of a maritime boundary from 2008 to 2014, Ghana points to its opening statement at the first meeting in July 2008, which expressly “proposes that the international boundary in existence, which is used by international Petroleum Companies, with PETROCI and GNPC as partners, on behalf of Côte d’Ivoire and Ghana respectively … be formalized and signed as our common maritime boundary”. According to Ghana, the minutes of the meeting show that “what drove the convening of the meeting was not a sense that there was no existing maritime boundary”, but rather a concern that submissions to the CLCS “would be assisted by parties concluding a treaty formalizing their existing maritime boundary, and doing so by May 2009”. Ghana thus rejects Côte d’Ivoire’s argument that the initiation of the negotiation on delimitation in 2008 is evidence of the absence of an agreed maritime boundary.

• 189. Ghana further states that the dispute between the Parties started on 23 February 2009 during the second meeting, when Côte d’Ivoire abruptly changed course, “unexpectedly repudiating the customary equidistance line” and presenting “a new line on which it had never previously relied—the so-called ‘geographic meridian approach’”. According to Ghana, this approach ignored half a century of agreement on the customary equidistance line. Ghana asserts that Côte d’Ivoire did so “only after the discovery of oil on Ghana’s side of the equidistance line”. Ghana adds that Côte d’Ivoire has since repeatedly changed its position on the method of delimitation.

• 190. Ghana notes that at the second meeting, Côte d’Ivoire requested that “ongoing exploration and evaluation works undertaken by Ghana west of that meridian [claimed by Côte d’Ivoire] be stopped” and “suddenly claimed that it had made earlier requests, in 1988 and 1992”. Ghana claims that it “sought information on those purported ‘requests’, but none came” until six years later, at the provisional measures hearing, when it finally saw the claimed 1992 “request”. However, according to Ghana, it offers no support for Côte d’Ivoire’s position (see para. 187).

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• 191. The Special Chamber observes that the Parties disagree on the significance of the bilateral exchanges in 1988 and 1992 as well as the bilateral negotiations from 1988 to 2014. With respect to the exchanges in 1988 and 1992, the Special Chamber considers that while the evidence relating to them is limited and their exact content is less [Page 454] than clear, the fact that they took place, which is uncontested between the Parties, is of relevance to the Special Chamber’s task of determining whether a tacit maritime boundary exists. As regards the bilateral negotiations between 2008 and 2014, the Special Chamber has enough information, including the minutes of the meetings of the Commission on Maritime Border Demarcation, to determine what they are about. The Special Chamber notes in this regard that at those meetings the Parties engaged in substantive discussion as to what should be the appropriate method to delimit their maritime zones. The Special Chamber also notes that only in 2011 did Ghana introduce its argument regarding a tacit agreement for the first time. The Special Chamber is therefore not convinced by Ghana’s argument that the purpose of the bilateral negotiations was simply to formalize a maritime boundary tacitly agreed upon between the Parties.

• 192. The Special Chamber also takes note of the two joint statements of 4 November 2009 and 11 May 2015 made by the Presidents of Ghana and Cȏte d’Ivoire. In these statements, the Presidents refer to an agreement on the maritime boundary to be reached in the future. The fact that substantially identical statements were made indicates that no such agreement had been reached between the two States on the delimitation of their maritime boundary in the territorial sea, the exclusive economic zone and the continental shelf within and beyond 200 nm.

F. Other maritime activities

• 193. Prior to the hearing, the Special Chamber posed a question to both Parties: “[c]ould the Parties provide information on any arrangements which could exist between them on fisheries matters or with respect to other uses of the maritime areas concerned?”

• 194. According to Ghana, there are no arrangements between the Parties with respect to fisheries. However, it has an arrangement with a private company that monitors the movement of licensed fishing vessels. Ghana states that the map on which this company relies in its arrangement with Ghana shows an equidistance boundary with Côte d’Ivoire. Ghana also refers to the Fisheries Partnership Agreement (FPA) concluded between Côte d’Ivoire and the European Union (EU), which allows EU vessels to fish in Ivorian waters. According to Ghana, the expert report evaluating the implementation of the FPA in the waters of Côte d’Ivoire states that European vessels rely on the equidistance limits in the absence of “exact coordinates of the EEZ [Page 455] limits”. It is therefore the understanding of Ghana that EU fishing vessels are using an equidistance boundary and are doing so with the full knowledge of both Côte d’Ivoire and the EU. Ghana adds that the United Nations Food and Agriculture Organization (FAO) has published material that shows Côte d’Ivoire’s fishing limit with Ghana as being an equidistance line. Ghana contends that these maps and the report confirm that it is this limit, following the customary equidistance line, that the EU fishing vessels and the private company consider as the eastern maritime boundary of Côte d’Ivoire.

• 195. For its part, Côte d’Ivoire states that the Parties signed an agreement on fishing and oceanographic research on 23 July 1988, under which they authorize fishing boats and oceanographic vessels to operate in each other’s territorial sea and exclusive economic zones. Côte d’Ivoire points to article 12, which provides that: “[t]his Agreement shall not affect the rights, claims or views of either Contracting Party with regard to the limits of its territorial waters or its fisheries jurisdiction”.

• 196. For Côte d’Ivoire, it is clear from this provision that in 1988 the negotiating States contemplated that “there could be differing rights, claims and views on limits and jurisdiction over fisheries”. On the other hand, Côte d’Ivoire argues that the maps and the report referred to by Ghana in its response have “no probative value” because they are prepared by private experts or contain the usual disclaimers.

  * * *

• 197. The Special Chamber considers that the Parties’ answers to the question it posed indicate that there are no specific arrangements between them on fisheries or other maritime matters. Although it appears that the Parties follow an equidistance line in their fishing activities, there is no evidence to suggest that the Parties recognize such line as their fishery or maritime boundary. In the view of the Special Chamber, the other maritime activities of the Parties fall short of proving the existence of any agreed maritime boundary between them.

G. Standard of proof

• 198. The Special Chamber now turns to what the standard of proof required to show the existence of a tacit agreement should be.

• 199. Ghana acknowledges that the evidence establishing the existence of a tacit agreement must be “compelling”, as was observed by the [Page 456] ICJ in Territorial and Maritime Dispute in the Caribbean Sea (Nicaragua v. Honduras). However, Ghana argues that “this is not, and should not be, an unattainable standard”. In particular, Ghana contends that the “compelling” standard “does not imply that only [those] tacit agreements that have been subsequently confirmed by a written document”, as was the case in Maritime Dispute (Peru v. Chile), can be recognized. In Ghana’s view, the ICJ did not require such confirmation in the form of a written agreement as a condition for recognition of a tacit agreement in its Judgment in Maritime Dispute (Peru v. Chile) and there is no reason as to why the Special Chamber should be more demanding in this respect.

• 200. Ghana argues that “the history of both States’ conduct in the present case is compelling, and leaves no room for doubt as to the existence of a mutual agreement between them on the location of their common border along the equidistance line”.

• 201. Ghana points to the “special value of mutual oil practice as evidence of a tacit agreement on a common border”. Ghana refers to the ICJ’s statement in Land and Maritime Boundary (Cameroon v. Nigeria: Equatorial Guinea intervening) that “the existence of an express or tacit agreement between the parties on the siting of their respective oil concessions may indicate a consensus on the maritime areas to which they are entitled”. Ghana also refers to Continental Shelf (Tunisia/Libyan Arab Jamahiriya), in which the ICJ emphasized that the line “of adjoining concessions, which was tacitly respected for a number of years … does appear to the Court to constitute a circumstance of great relevance for the delimitation”. According to Ghana, this is indeed the case here, in light of the much longer period over which the Parties’ mutual practice regarding oil exploration and exploitation in the border area was consistently carried out without any conflict.

• 202. Ghana rejects Côte d’Ivoire’s contention that in this case Ghana “merely invokes a simple practice, which is limited … to the oil sector”. For Ghana, nothing could be further from the truth. In Ghana’s view, the case-file before the Special Chamber demonstrates clearly that the two Parties have recognized “a maritime boundary whose existence is autonomous of the limits of their oil concessions”. It is this boundary that serves as “the basis, the point of reference, for drawing the limits of the maritime concessions and for the activities conducted in the maritime areas in question”.

• 203. Ghana argues that Côte d’Ivoire’s abandonment of the long-agreed boundary in February 2009 marks “the critical date when the dispute between the two States crystallized”. In this regard, Ghana [Page 457] refers to the statement made by the ICJ in Sovereignty over Pulau Ligitan and Pulau Sipadan (Indonesia/Malaysia):

  it cannot take into consideration acts having taken place after the date on which the dispute between the Parties crystallized unless such acts are a normal continuation of prior acts and are not undertaken for the purpose of improving the legal position of the Party which relies on them.

  (Judgment, ICJ Reports 2002, p. 625, at p. 682, para. 135)

  According to Ghana, “[a]ny and all self-serving activities undertaken by Côte d’Ivoire with respect to the maritime boundary after this date lack legal relevance for purposes of determining where the boundary lies”. Ghana notes that such activities of Côte d’Ivoire include “its alterations of maps and its designation of new concession blocks to the east of the historical equidistance line”.

• 204. Côte d’Ivoire maintains that the burden of proof for a tacit agreement lies with the State which claims it—Ghana in this case—and that the conditions for recognition of a tacit agreement on maritime delimitation are “particularly strict”. According to Côte d’Ivoire, this explains why the argument of tacit agreement has generally been rejected by judicial bodies.

• 205. In this regard, Côte d’Ivoire refers to Maritime Dispute (Peru v. Chile), the only case in which the existence of a tacit agreement concerning a maritime boundary was recognized. In Côte d’Ivoire’s view, the crucial factor in recognition of a tacit agreement in that case was the existence of a treaty between the Parties which expressly referred to that tacit agreement. However, Côte d’Ivoire notes that in the present case Ghana does not claim that any express confirmation exists. According to Côte d’Ivoire, although the jurisprudence does not always require the existence of a treaty, the absence of a written instrument makes proof of a tacit agreement particularly difficult for the State claiming its existence.

• 206. Côte d’Ivoire maintains that Ghana has failed to meet the high standard of proof required for recognition of a tacit agreement on maritime delimitation. Côte d’Ivoire notes that “Ghana’s argument that there is a ‘customary equidistance line’ between the Parties is based almost exclusively on their oil activities”, in particular relative alignment of concessions and seismic cooperation. Côte d’Ivoire indicates, however, that international courts and tribunals are “extremely reluctant, and even refuse, to take into consideration oil practice, however intensive, for the purposes of delimiting the maritime boundary”. In Côte d’Ivoire’s view, “[o]il practice can follow an agreement, be it express or tacit, reflect or support it, but it cannot constitute an agreement”. Consequently, the [Page 458] party that invokes the agreement must first prove it before referring to concessions as “confirmatory effectivités”.

• 207. Côte d’Ivoire also argues that petroleum conduct says nothing about any of the other sovereign rights, jurisdiction and duties of the coastal State in the exclusive economic zone or over the continental shelf. Accordingly, in Côte d’Ivoire’s view, Ghana’s attempt to “extrapolate from this limited petroleum conduct an all-purpose maritime boundary dividing the seabed and the water column of the exclusive economic zones and the continental shelf” is not tenable. Moreover, Côte d’Ivoire asserts that even the petroleum conduct itself is not as clear as Ghana claims and has been contested by Côte d’Ivoire.

• 208. In response to Ghana’s argument regarding the critical date, Côte d’Ivoire notes that it did not see the critical date “as a matter that could assist the Chamber”. For Côte d’Ivoire, “it is hard to say when a dispute arises in the case of an undelimited international maritime boundary”. Côte d’Ivoire observes that although Ghana puts the date as February 2009, which “they no doubt consider to be the most favourable date for them”, the date selected could well have been 1988, as Côte d’Ivoire suggested in the Rejoinder, 1992, 2011, or 2014, when the case was submitted to arbitration. Côte d’Ivoire thus contends that the critical date test is hardly helpful in a case such as this one and that the Special Chamber does not need to determine the critical date.

  * * *

• 209. The Special Chamber notes that the Parties disagree as to whether the standard of proof for the existence of a tacit agreement has been met in the present case. It will give its conclusions on that in the following paragraphs.

• 210. The Special Chamber further notes the different positions of the Parties about the critical date. However, it is of the view that the activities of both Parties in the maritime area under consideration have not changed over the years. For that reason, the Special Chamber does not consider that the notion of critical date is relevant in the present case.

H. Conclusions of the Special Chamber on the existence of a tacit agreement

• 211. The Special Chamber has already indicated that Ghana claims in this case that there is a tacit agreement between the Parties with [Page 459] respect to a maritime boundary delimiting the territorial sea, exclusive economic zone and continental shelf both within and beyond 200 nm and that the boundary follows an equidistance line. The Special Chamber must therefore determine whether there is a tacit agreement between the Parties on a maritime boundary.

• 212. At the outset, the Special Chamber recalls the observation made by the ICJ in Territorial and Maritime Dispute between Nicaragua and Honduras in the Caribbean Sea (Nicaragua v. Honduras): “Evidence of a tacit legal agreement must be compelling. The establishment of a permanent maritime boundary is a matter of grave importance and agreement is not easily to be presumed” (Judgment, ICJ Reports 2007 (II), p. 659, at p. 735, para. 253).

• 213. The Special Chamber notes that the evidence adduced by Ghana shows that the Parties’ oil activities, such as the granting of oil concessions, seismic surveys, and drilling operations, have been carried out along the line which Ghana refers to as the “customary equidistance boundary”. The Special Chamber further notes that the oil concession maps submitted to it attest to the above facts. The Special Chamber acknowledges that the practice has been consistent and mutual over a long period of time, although it is not free of controversy or doubt.

• 214. In this regard, the Special Chamber takes note of the claim made by Côte d’Ivoire that it requested on several occasions, including first in 1992 and then in 2009 and 2011, that the Parties should refrain from any unilateral activity in the area to be delimited. In the view of the Special Chamber, Côte d’Ivoire’s requests cast doubt on Ghana’s claim that the Parties’ oil practice has been unequivocal over more than five decades. In any event, as far as the Parties’ oil practice is concerned, whether or not its character is unequivocal is not the main consideration of the Special Chamber.

• 215. The Special Chamber considers that the oil practice, no matter how consistent it may be, cannot in itself establish the existence of a tacit agreement on a maritime boundary. Mutual, consistent and long-standing oil practice and the adjoining oil concession limits might reflect the existence of a maritime boundary, or might be explained by other reasons. As the ICJ stated in Territorial and Maritime Dispute between Nicaragua and Honduras in the Caribbean Sea (Nicaragua v. Honduras):

  A de facto line might in certain circumstances correspond to the existence of an agreed legal boundary or might be more in the nature of a provisional line or of a line for a specific, limited purpose, such as sharing a scarce resource. Even if there had been a provisional line found convenient for a period of time, this is to be distinguished from an international boundary.

  (Judgment, ICJ Reports 2007 (II), p. 659, at p. 735, para. 253)

  [Page 460] As the ICJ also stated with respect to oil concession limits in Sovereignty over Pulau Ligitan and Pulau Sipadan (Indonesia/Malaysia): “[t]hese limits may have been simply the manifestation of the caution exercised by the Parties in granting their concessions” (Judgment, ICJ Reports 2002, p. 625, at p. 664, para. 79). Thus the proof of the existence of a maritime boundary requires more than the demonstration of longstanding oil practice or adjoining oil concession limits.

• 216. The Special Chamber observes that Ghana indeed argues that the oil practice of the Parties shows not only the limits of their oil concessions but also the existence of their maritime boundary by referring, inter alia, to the particular way a boundary line is depicted on oil concession maps, the Parties’ correspondence concerning seismic surveys in the vicinity of the alleged boundary, and the words employed in the Parties’ legislation.

• 217. As far as oil concession maps are concerned, the Special Chamber is not convinced that these maps show not only the limits of oil concessions but also maritime boundaries as Ghana claims. The Special Chamber notes that a number of oil concession maps proffered by Ghana depict a broken line, starting from the land boundary terminus and extending beyond the seaward limits of the oil concession, with the names of one or both Parties on each side of the line. In the absence of a clear reference to an international maritime boundary on the maps, it is difficult to accept such depiction of a line as an indication of an international maritime boundary.

• 218. The Special Chamber recalls that Côte d’Ivoire, in authorizing Ghanaian licensees to enter into its maritime area in order to conduct seismic surveys, specifically refers to the Ivorian territorial waters near the “maritime boundary between Ghana and Côte d’Ivoire”. Ghana considers this to be Côte d’Ivoire’s explicit recognition of a maritime boundary between the two States. However, the Special Chamber cannot accept Ghana’s argument, as the mere use of the term “maritime boundary” cannot prove the existence of an “agreed” maritime boundary any more than a map depicting a line in a particular way does.

• 219. As regards the decree of 29 July 1957, the Special Chamber cannot accept, for the reasons set out above, Ghana’s argument that it is the first example of legislation recognizing the existence of the maritime boundary between the Parties. With respect to Presidential Decree 70–618, the Special Chamber finds it difficult to accept, for the reasons set out above, that it constitutes compelling evidence establishing a tacit agreement on a maritime boundary. Nor can the Special [Page 461] Chamber accept that the 1977 Law of Côte d’Ivoire recognizes the “principle of equidistance” as the most appropriate method of delimitation of Côte d’Ivoire’s maritime boundary with Ghana. Article 8 of the 1977 Law expressly provides that the equidistance line is to be used, “if necessary”, and there is no indication in the Act that the use of such a line is necessary in the delimitation of a maritime boundary between Côte d’Ivoire and Ghana.

• 220. The Special Chamber considers that the Parties have been aware of the distinction between oil concession limits and the maritime boundary. The awareness that oil concession limits and the maritime boundary are distinct is clearly reflected in the Parties’ attempts to delimit their maritime boundary by negotiation, first in 1988, then in 1992, and eventually from 2008 to 2014. It is also reflected in the Parties’ submissions to the CLCS. In the Special Chamber’s view, Côte d’Ivoire has been particularly cautious in making sure that the limits of its oil concession blocks are distinct from those of its maritime jurisdiction, as the provision in its oil concession contracts states. Nor was Ghana unaware of such a distinction, as its letter to Tullow in 2011 testifies.

• 221. As regards the bilateral exchanges in 1988 and 1992, the Special Chamber notes that the Parties agree that they took place but differ as to their exact content and significance to the present dispute. In the Special Chamber’s view, the fact that these bilateral exchanges took place at all is relevant, because it shows that the Parties recognized the need to delimit a maritime boundary between them.

• 222. The subsequent bilateral negotiations at the Commission on Maritime Border Demarcation from 2008 to 2014 confirm the Parties’ recognition of the absence of a maritime boundary between them. In this regard, the Special Chamber recalls the argument advanced by Ghana that the purpose of the bilateral exchanges and negotiations was simply to “formalize” what the Parties had already agreed “in practice and principle”. In the Special Chamber’s view, even if it may have been the intention of Ghana, there is no evidence to indicate that it was also Côte d’Ivoire’s intention. On the contrary, Côte d’Ivoire has made a distinction between oil concession limits and a maritime boundary.

• 223. Moreover, a close examination of the minutes of the meetings of the Commission on Maritime Border Demarcation shows that the purpose of the meeting was more than simply formalizing what had already been agreed. At those meetings, the Parties engaged in substantive discussion on various aspects of delimitation, in particular on the delimitation method to be applied.

• [Page 462] 224. The Special Chamber considers that the Parties’ submissions to the CLCS are another indication of the absence of any agreement between them on a maritime boundary. The submissions, including the amended submission of Côte d’Ivoire, clearly stated, in identical terms, that Ghana or Côte d’Ivoire has overlapping maritime claims with adjacent States and has not signed any delimitation agreements with any of its neighbouring States to date. They also include a provision that the submission of information to the CLCS is without prejudice to delimitation of the maritime boundary with neighbouring States. Ghana’s submission specifically refers to the “Republic of Côte d’Ivoire” as one of the neighbouring States, and Côte d’Ivoire’s submission likewise refers to the “Republic of Ghana”.

• 225. The Special Chamber observes that States often offer and award oil concessions in an area yet to be delimited. It is not unusual for States to align their concession blocks with those of their neighbouring States so that no areas of overlap arise. They obviously do so for different reasons, but not least out of caution and prudence to avoid any conflict and to maintain friendly relations with their neighbours. To equate oil concession limits with a maritime boundary would be equivalent to penalizing a State for exercising such caution and prudence. It would be contrary to article 74, paragraph 3, and article 83, paragraph 3, of the Convention, which require States, pending agreement on delimitation, in a spirit of understanding and cooperation, not to jeopardize or hamper the reaching of the final agreement. It would also entail negative implications for the conduct of States in the area to be delimited elsewhere.

• 226. The Special Chamber has another reason not to accept Ghana’s argument for the existence of a tacit agreement on a maritime boundary. The boundary the Special Chamber has to delimit is a single maritime boundary delimiting the territorial sea, exclusive economic zone and the continental shelf. In the Special Chamber’s view, evidence relating solely to the specific purpose of oil activities in the seabed and subsoil is of limited value in proving the existence of an all-purpose boundary which delimits not only the seabed and subsoil but also superjacent water columns. As the ICJ stated in Maritime Dispute (Peru v. Chile), “the all-purpose nature of the maritime boundary … means that evidence concerning fisheries activity, in itself, cannot be determinative of the extent of that boundary” (Judgment, ICJ Reports 2014, p. 3, at p. 45, para. 111).

• 227. The Special Chamber recalls in this regard that the Parties did not provide a clear answer to the question it posed with respect to fisheries and other maritime activities. The conduct of the Parties with [Page 463] respect to matters other than oil concessions and operations seems to confirm the uncertainty as to the maritime boundary, and add little, if anything, to the proof of the existence of a tacit agreement.

• 228. In light of the foregoing, the Special Chamber concludes that there is no tacit agreement between the Parties to delimit their territorial sea, exclusive economic zone and continental shelf both within and beyond 200 nm.

A. Delimitation of the territorial sea

• 248. The Parties disagree on the delimitation of their territorial seas.

• 249. Ghana argues that article 15 of the Convention “stipulates the primacy of agreement, and failing that the application of the principle [Page 467] of equidistance”. It explains that “[d]eparture from the equidistance principle is possible only where necessary by reason of historic title or other ‘special circumstances’”.

• 250. Ghana further argues that, “[a]lthough not formalized in a maritime delimitation treaty, since the late 1950s Ghana and Côte d’Ivoire have mutually recognised and agreed and given effect to a boundary in the territorial sea (and beyond) based on equidistance that commences at BP 55”. It is of the view that “[t]he compelling evidence before the Special Chamber, coupled with the settled practice, reflects a binding commitment within the meaning of Article 15 of the 1982 Convention”.

• 251. Ghana contends that “[i]n the absence of any historic title or other special circumstance—and none exist here—there is no ground for departing from this historically-agreed line, as reflected in the consistent conduct of Ghana and Côte d’Ivoire for over 50 years”. It adds that “[t]here are … no geographic or geologic features that call for a departure from an equidistance-based boundary”.

• 252. Ghana further contends that “there is no basis in fact or law for a territorial sea boundary based on either of the two methods of delimitation advanced by Côte d’Ivoire”. It emphasizes that “[t]he bisector method has only been used in very limited and unusual circumstances, where the conventional approach is manifestly inappropriate or impossible to apply”.

• 253. Côte d’Ivoire submits that article 15 of the Convention “advocates using the equidistance line or the median line for delimitation of the territorial sea, but the basic rule may be subject to exceptions if special circumstances exist”.

• 254. Côte d’Ivoire further submits “that special circumstances exist and they make it necessary for the Chamber to delimit the territorial sea using a method other than the equidistance line”. It is of the view that “[t]he ‘bisector method’ is the most appropriate method in the present case” and requests the Special Chamber “to delimit the Ivorian-Ghanaian maritime boundary in the territorial sea, the exclusive economic zone and the continental shelf up to 200 nautical miles according to a 168.7° azimuth line from boundary post 55”.

• 255. Côte d’Ivoire argues that it “bases its position on the existence of particular geographic and geomorphological characteristics which warrant the application of the bisector method”. It further argues that “the same geographic and geomorphological circumstances are applicable to delimitation of the territorial sea and of the maritime areas beyond the territorial sea”.

• 256. Côte d’Ivoire submits, “on a subsidiary basis, that if the Chamber were to opt for the equidistance/relevant circumstances [Page 468] method, … [objective] circumstances do exist in the present case and necessitate the adjustment of the provisional equidistance line in order to achieve an equitable result”.

  * * *

• 257. The Special Chamber summarizes the submissions of the Parties in respect of the delimitation of their territorial seas as follows. Both Parties, in their final submissions, ask the Special Chamber to draw a single maritime boundary delimiting their territorial seas, exclusive economic zones and continental shelves both within and beyond 200 nm. Ghana bases its request for the delimitation of the territorial seas on the application of the equidistance methodology while referring to article 15 of the Convention. Côte d’Ivoire, in turn invoking special circumstances, argues in favour of the application of the angle bisector methodology for the delimitation of the territorial sea as it does for the exclusive economic zones and the continental shelves. The Special Chamber notes that the same disagreement over the appropriate delimitation methodology exists between the Parties in respect of the delimitation of the exclusive economic zones and the continental shelves within and beyond 200 nm.

• 258. The Special Chamber notes that the Parties have not put forward comprehensive arguments concerning the delimitation of the territorial sea on the basis of article 15 of the Convention. Ghana merely stated that neither historic titles nor special circumstances exist and that there is therefore no ground for departing from the “historically-agreed line”. It also stated that there are no geographic or geological features that call for a departure from an equidistance boundary. In respect of the delimitation of the exclusive economic zone and the continental shelf within and beyond 200 nm, Ghana equally advocated the “historically-agreed line” or the equidistance line. Côte d’Ivoire in turn argued that “special circumstances exist” which make it appropriate to use for the delimitation of the territorial sea the bisector methodology which it also advocated for the exclusive economic zone and the continental shelf within and beyond 200 nm. The Special Chamber notes that the “special circumstances” referred to by Côte d’Ivoire were exemplified only in the context of the delimitation of the exclusive economic zone and the continental shelf within and beyond 200 nm.

• 259. The Special Chamber interprets the submissions of both Parties to the effect that it should use the same delimitation methodology for the whole delimitation process, namely the methodology developed for the delimitation of exclusive economic zones and continental shelves.

• [Page 469] 260. It is for that reason that the Special Chamber will address the question of the appropriate delimitation methodology when it deals with the delimitation of the exclusive economic zones and continental shelves of the Parties. Nevertheless, the Special Chamber emphasizes that under the Convention different rules apply to the delimitation of territorial seas and the delimitation of exclusive economic zones and continental shelves.

• 261. The Special Chamber notes that the delimitation of the territorial sea is governed by article 15 of the Convention, which reads:

  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 baseline 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.

• 262. The Special Chamber considers it important to note that in delimiting the territorial sea it has to be borne in mind that the rights of the coastal States concerned are not functional but territorial since they entail sovereignty over the seabed, the superjacent waters and the air column above. This has been emphasized by the ICJ in Maritime Delimitation and Territorial Questions between Qatar and Bahrain (Qatar v. Bahrain) (Merits, Judgment, ICJ Reports 2001, p. 40, at p. 93, paras. 173-4). However, neither Ghana nor Côte d’Ivoire raised sovereignty-related considerations in respect of the delimitation of the territorial sea between them. The Special Chamber notes that the Parties, in requesting the Special Chamber to delimit a single maritime boundary for their territorial seas, exclusive economic zones and continental shelves, have implicitly agreed that the same delimitation methodology be used for these maritime spaces.

• 263. On this basis, the Special Chamber considers it appropriate to use the same methodology for the delimitation of the Parties’ territorial seas, exclusive economic zones and continental shelves within and beyond 200 nm.

B. Delimitation of the territorial sea, the exclusive economic zone and the continental shelf within 200 nm

C. Delimitation of the continental shelf beyond 200 nm

D. Disproportionality test

• 528. The Special Chamber will now proceed to the third stage of the delimitation procedure, namely the disproportionality test.

• 529. Ghana, relying on the decision of the ICJ in Maritime Delimitation in the Black Sea, states that

  [t]he third and final step of the process is to consider whether the delimitation line developed by application of the first two steps “lead[s] to any significant disproportionality by reference to the respective coastal lengths and the apportionment of areas that ensue”.

  It argues that

  [t]he case law prescribes that the disproportionality test consists of comparing the ratio of the Parties’ relevant coasts to the ratio of the allocated portions of the relevant maritime area to determine if they are significantly disproportionate.

• 530. In Ghana’s view, “[t]he ratio of the lengths of the Parties’ relevant coasts is 2.55 to 1” and “[t]he overlapping projections of these coasts cover a maritime area of 189,547 sq. km”.

• 531. Côte d’Ivoire maintains that “the test of non-disproportionality … is the third stage of the equidistance/relevant circumstances method”. Referring to the decision of the ICJ in Maritime Dispute (Peru v. Chile), Côte d’Ivoire further maintains with regard to that test that it has to be seen “whether the equidistance line adjusted according to the relevant circumstances ‘produces a result which is significantly disproportionate in terms of the lengths of the relevant coasts and the division of the relevant area’”.

• 532. Côte d’Ivoire submits that “the Ivorian relevant coasts are 4.2 times longer than those of Ghana; so that is 4.2 to 1 in favour of Côte d’Ivoire”. Côte d’Ivoire further submits that

  [t]he relevant area measures approximately 75,742 M² in total (including the maritime areas within 200 nautical miles and the continental shelf beyond), assuming its lateral limits are equidistance on the Liberian side and a line perpendicular to the coast of Ghana, starting from the promontory of Cape Three Points.

  * * *

• 533. The third stage in applying the equidistance/relevant circumstances methodology requires verification that the delimitation line constructed by application of the first two stages of this methodology does not lead to an inequitable result owing to a marked disproportion [Page 524] between the ratio of the respective coastal lengths and the ratio of the relevant maritime area allocated to each Party. In this respect, the Special Chamber follows the approach of the ICJ in Maritime Delimitation in the Black Sea (Romania v. Ukraine) (Judgment, ICJ Reports 2009, p. 61, at p. 103, para. 122), which was also adopted in the Judgment of the Tribunal in the dispute concerning Delimitation of the maritime boundary in the Bay of Bengal (Bangladesh/Myanmar) (Judgment, ITLOS Reports 2012, p. 4, at p. 123, para. 477). The Special Chamber notes that in conducting the disproportionality test, the relevant area encompasses the entire area under dispute identified in paragraphs 381-6 above (see Delimitation of the maritime boundary in the Bay of Bengal (Bangladesh/Myanmar), Judgment, ITLOS Reports 2012, p. 4, at p. 125, para. 493; Bay of Bengal Maritime Boundary Arbitration between Bangladesh and India, Award of 7 July 2014, para. 490).

• 534. As was stated in paragraph 386, the size of the relevant area has been calculated to be approximately 198,723 square kilometres. The Special Chamber is bound to emphasize that under the particular circumstances of this case this figure can only be an approximation. This is due to the fact that the outer limits of the continental shelf beyond 200 nm have not yet been finally established under article 76, paragraph 8, of the Convention. Nevertheless the Special Chamber finds that this figure is sufficient to conduct the disproportionality test.

• 535. The Special Chamber will now establish whether the equidistance line has caused a significant disproportion by reference to the ratio of the lengths of the coastlines of the Parties and the ratio of the relevant maritime area allocated to each Party.

• 536. As already established in paragraph 379 above, the length of the relevant Ghanaian coast is 139 kilometres and that of Côte d’Ivoire is 352 kilometres. The ratio of the length of the relevant coasts of the Parties is approximately 1:2.53 in favour of Côte d’Ivoire.

• 537. The Special Chamber notes that its delimitation line allocates approximately 65,881 square kilometres to Ghana and 132,842 square kilometres to Côte d’Ivoire. The ratio of the allocated areas is approximately 1:2.02 in favour of Côte d’Ivoire. The Special Chamber finds that this ratio does not lead to any significant disproportion in the allocation of maritime areas to the Parties relative to the respective lengths of their relevant coasts.

• 538. The Special Chamber concludes that, taking into account all the circumstances of the present case, the result achieved by the application of the delimitation line adopted in paragraphs 481 and 527 of the Judgment does not entail such disproportionality as to create an unequitable result.

E. Conclusion on delimitation

• 539. All coordinates and azimuths used by the Special Chamber in this Judgment are given by reference to WGS 84 as a geodetic datum.

• 540. The single maritime boundary for the territorial sea, the exclusive economic zone and the continental shelf within and beyond 200 nm starts at BP 55+ with the coordinates 05° 05′ 23.2″ N, 03° 06′ 21.2″ W and is defined by turning points A, B, C, D, E, F with the coordinates set out in paragraph 401 and connected by geodetic lines. From turning point F, the single maritime boundary continues as a geodetic line starting at an azimuth of 191° 38′ 06.7″ (see para. 481) until it reaches the outer limits of the continental shelf.

A. Introduction

• 541. The Special Chamber now turns to the issue of the international responsibility of Ghana.

• 542. Côte d’Ivoire submits that Ghana’s conduct in the disputed part of the continental shelf violated international law, the Convention, and the Order for the prescription of provisional measures of 25 April 2015.

• 543. In response, Ghana submits that the allegations made by Côte d’Ivoire are unfounded, emphasizing that it acted in compliance with international law at all times and complied faithfully with the Order of the Special Chamber of 25 April 2015.

• 544. Côte d’Ivoire invokes three different grounds for its claim that Ghana is internationally responsible. First, it bases its claim upon an alleged violation of Côte d’Ivoire’s sovereign rights by Ghana by conducting or licensing hydrocarbon activities in an area over which Côte d’Ivoire claims to have sovereign rights; second, it invokes a violation of article 83 of the Convention; and, third, it claims that Ghana acted contrary to its obligations as set out in the Order of the Special Chamber of 25 April 2015. The Special Chamber will deal with each of these claims and the arguments exchanged between the Parties in this respect in turn.

B. Jurisdiction of the Special Chamber to decide on international responsibility of Ghana

• 545. Before deciding on international responsibility, the Special Chamber has to ascertain that it has jurisdiction to entertain the claim [Page 526] invoking Ghana’s international responsibility. The Special Chamber notes that Ghana does not question the Special Chamber’s jurisdiction to decide on the claims of Côte d’Ivoire concerning Ghana’s alleged international responsibility. Considering that jurisdiction is the very [Page 527] basis of its judicial functions, the Special Chamber holds that it has to ascertain its jurisdiction proprio motu although such jurisdiction has not been disputed by Ghana. The Special Chamber will first ascertain whether the Special Agreement of 3 December 2014 provides for [Page 528] jurisdiction to decide on claims for international responsibility in this case.

• 546. The Special Chamber would like to underline at the outset that jurisdiction to adjudicate over the alleged violation of the provisional measures prescribed by its Order of 25 April 2015 (see final submission no 3 of Côte d’Ivoire) belongs to the inherent competence of the Tribunal. Accordingly, the question as to whether the Special Chamber has jurisdiction to decide on the international responsibility of Ghana arises only in respect of final submission no 2 of Côte d’Ivoire.

• 547. The Special Chamber notes that in the Special Agreement the Parties recorded “their agreement to submit to a special chamber of the International Tribunal for the Law of the Sea the dispute concerning the delimitation of their maritime boundary in the Atlantic Ocean”, thus describing and at the same time limiting the scope of the dispute. The Minutes of Consultations agreed between Ghana and Côte d’Ivoire on 3 December 2014 (see para. 5) describe the scope of the dispute in identical terms. The first question to be decided is whether the words “dispute concerning the delimitation of their maritime boundary in the Atlantic Ocean” also embrace a dispute on international responsibility deriving from hydrocarbon activities in the disputed area.

• 548. The Special Chamber concedes that the word “concerning” may be understood to include within the scope of the dispute other issues which are not part of delimitation but are closely related thereto. It is evident that the dispute between Ghana and Côte d’Ivoire on international responsibility arose out of the delimitation dispute between them. However, in the view of the Special Chamber, it would stretch the meaning of the words “dispute concerning the delimitation of their maritime boundary” too much to interpret it in such a way that it included a dispute on international responsibility.

• 549. The position that it is not possible to include final submission no 2 of Côte d’Ivoire on international responsibility in the original dispute on delimitation is, in the view of the Special Chamber, supported if consideration is given to the Notification under article 287 and Annex VII, article 1, of 19 September 2014 of Ghana, which described the mandate of the dispute-settlement mechanism. It reads:

  the establishment of the single maritime boundary between Ghana and Côte d’Ivoire in the Atlantic Ocean delimiting the territorial sea, exclusive economic zone (“EEZ”) and continental shelf, including the continental shelf beyond 200 nautical miles.

• [Page 529] 550. On the basis of these considerations, the Special Chamber concludes that its jurisdiction to decide on final submission no 2 of Côte d’Ivoire concerning the alleged international responsibility of Ghana is not covered by the Special Agreement by which the dispute concerning delimitation was submitted to it.

• 551. Therefore, the Special Chamber will now ascertain whether the Parties, following institution of the proceedings, have implied by their conduct in the pleadings on the merits that they accepted the jurisdiction of the Special Chamber to deal with the claim concerning Ghana’s international responsibility.

• 552. International jurisprudence has accepted that the jurisdiction of an international court or tribunal may be broadened by the conduct of parties in the proceedings (forum prorogatum). The ICJ, in the Armed Activities on the Territory of the Congo case, summarized the relevant jurisprudence on forum prorogatum as follows:

  The attitude of the respondent State must … be capable of being regarded as “an unequivocal indication” of the desire of that State to accept the Court’s jurisdiction in a “voluntary and indisputable” manner (Corfu Channel (United Kingdom v. Albania), Preliminary Objection, Judgment, 1948, ICJ Reports 1947-1948, p. 27); Application of the Convention on the Prevention and Punishment of the Crime of Genocide (Bosnia and Herzegovina v. Yugoslavia (Serbia and Montenegro), Provisional Measures, Order of 13 September 1993, ICJ Reports 1993, p. 342, para. 34 … ).

  (Armed Activities on the Territory of the Congo (New Application: 2002) (Democratic Republic of the Congo v. Rwanda), Jurisdiction and Admissibility, Judgment, ICJ Reports 2006, p. 6, at pp. 18-19, para. 21)

• 553. As mentioned above (see para. 545), Ghana has not objected to the Special Chamber deciding on the allegation that it is internationally responsible. On the contrary, in its Reply as well as at the hearing, Ghana argued against the claim made by Côte d’Ivoire. Ghana denied that it had breached general international law or its obligations under the Convention or those set out in the Order of the Special Chamber of 25 April 2015. In its final submissions Ghana requested the Special Chamber to reject Côte d’Ivoire’s submissions concerning Ghana’s international responsibility as unfounded in substance. This conduct leads the Special Chamber to conclude that Ghana accepted its jurisdiction to decide on the claim of international responsibility on the merits.

• 554. Therefore, the Special Chamber finds that it has jurisdiction to decide on Côte d’Ivoire’s claim against Ghana on the latter’s alleged international responsibility as well as on reparation.

• [Page 530] 555. The Special Chamber adds that articles 286 and 288 of the Convention, according to which the jurisdiction of the dispute-settlement bodies under Part XV of the Convention concerns the interpretation and application of the Convention, do not bar it from deciding on international responsibility. Although the Convention does not contain rules concerning international responsibility, article 293, paragraph 1, of the Convention provides for the possibility to have recourse to other rules of international law. Article 293, paragraph 1, of the Convention reads: “[a] court or tribunal having jurisdiction under this section shall apply this Convention and other rules of international law not incompatible with this Convention”.

• 556. Following the jurisprudence of the Tribunal (see M/V “Virginia G” (Panama/Guinea–Bissau), Judgment, ITLOS Reports 2014, p. 4, with reference to earlier jurisprudence of the Tribunal), the Special Chamber will revert to general international law when deciding on issues concerning international responsibility. The Special Chamber also recalls in this context article 304 of the Convention, which reads:

  The provisions of this Convention regarding responsibility and liability for damage are without prejudice to the application of existing rules and the development of further rules regarding responsibility and liability under international law.

• 557. As to the identification of the rules of general international law on international responsibility, the Special Chamber reiterates the Tribunal’s statement in its Judgment in the M/V “SAIGA” (No 2) Case, where it stated:

  It is a well-established rule of international law that a State which suffers damage as a result of an internationally wrongful act by another State is entitled to obtain reparation for the damage suffered from the State which committed the wrongful act and that “reparation must, as far as possible, wipe out all the consequences of the illegal act and reestablish the situation which would, in all probability, have existed if that act had not been committed”

  (Factory at Chorzów, Merits, Judgment No 13, 1928, PCIJ, Series A, No 17, p. 47).

  (M/V “SAIGA” (No 2), (Saint Vincent and the Grenadines v. Guinea), Judgment, ITLOS Reports 1999, p. 10, at p. 65, para. 170)

• 558. The Special Chamber observes that the Seabed Disputes Chamber of the Tribunal stated in its Advisory Opinion that several of the ILC Articles on Responsibility of States for Internationally Wrongful Acts are considered to reflect customary international law (see Responsibilities and obligations of States with respect to activities in the Area, Advisory Opinion, 1 February 2011, ITLOS Reports 2011, p. 10, [Page 531] at p. 56, para. 169). The Special Chamber adds that article 1 of the ILC Articles on Responsibility of States for Internationally Wrongful Acts also reflects customary international law. This article reads: “[e]very internationally wrongful act of a State entails the international responsibility of that State”.

• 559. Accordingly, the Special Chamber will decide on the alleged international responsibility of Ghana on the basis of the relevant customary international law, as reflected in several articles of the ILC Articles on Responsibility of States for Internationally Wrongful Acts.

• 560. The first step in deciding on a claim for the international responsibility of Ghana is to ascertain whether it has violated international law, to which the Special Chamber will now turn.

C. Violation of sovereign rights

• 561. In its final submissions, Côte d’Ivoire requests the special Chamber “to declare and adjudge that the activities undertaken unilaterally by Ghana in the Ivorian maritime area constitute a violation of: … the exclusive sovereign rights of Côte d’Ivoire over its continental shelf, as delimited by this Chamber”. Côte d’Ivoire submits that Ghana’s unilateral activities in this respect engage the latter’s responsibility.

• 562. In support of its claim, Côte d’Ivoire refers to the principle whereby “States should refrain from any unilateral economic activity in a disputed area pending a definitive delimitation”. Côte d’Ivoire refers to “three unchallenged foundations” of its argument on sovereign rights, namely that “the rights pertaining to the exploration and exploitation of the continental shelf are exclusive rights; … those rights exist ipso facto and ab initio; [and] the delimitation does not have the effect of creating them but of clarifying their scope”.

• 563. For Côte d’Ivoire, the “principle of exclusivity” of sovereign rights “requires that the exploration and exploitation of the continental shelf are conducted either by the coastal State itself, whether on its behalf or with its authorization, or with its express consent”. Côte d’Ivoire argues that exclusivity is an “inherent feature” of these rights.

• 564. Côte d’Ivoire argues that “the rights to the exploration and exploitation of the continental shelf … are timeless, a quality to which the term ‘ab initio’ also refers”. Côte d’Ivoire invokes the North Sea Continental Shelf cases in support of its submission concerning the inherent character of sovereign rights, and argues that “a logical consequence” of the “inherence of sovereign rights” is that “the exclusive [Page 532] rights to the continental shelf can be violated even when the delimitation line is still to be defined”.

• 565. Côte d’Ivoire maintains that the “delimitation judgment does not therefore create sovereign rights; it merely clarifies their geographic scope with the force of res judicata”. Côte d’Ivoire contends that its inherent rights to its continental shelf “predate” the Special Chamber’s Judgment on the merits and that therefore such Judgment “is not a precondition to the engagement of responsibility”. It explains, however, that a “judgment on the merits is certainly a precondition to the implementation of responsibility”, because it is only following the Judgment “that Côte d’Ivoire and Ghana will know the precise limit of their sovereign rights”.

• 566. Regarding the material scope of sovereign rights over the continental shelf, Côte d’Ivoire notes the finding of the Special Chamber in its Order of 25 April 2015 stating that these rights include “all rights necessary for or connected with the exploration of the continental shelf and the exploitation of its natural resources”. In this regard, it observes that, since seismic exploration is an activity “necessary for and connected with the exploration of the continental shelf”, it “constitutes a violation of sovereign rights if it has not been conducted with the express consent of the coastal State”.

• 567. Côte d’Ivoire submits that “international jurisprudence recognizes the principle whereby unilateral activities carried out or authorized by a coastal State in a contested marine area, under certain circumstances, engage the responsibility of those performing them when they violate the sovereign rights of another State”. According to Côte d’Ivoire, “[s]uch is the case of activities carried out in spite of the objections of the other State concerned, in an area which comes under the sovereign rights of that State, and the extent of which has been definitively established by the judgment or award relating to the delimitation”. Côte d’Ivoire refers to several international judicial decisions which, it submits, “recognize the principle of State responsibility for activities in a disputed area”.

• 568. Côte d’Ivoire states that “Ghana has engaged in extensive unilateral activities, both exploration and exploitation, in the disputed area” and that “[t]he oil exploration activities conducted by Ghana in the majority of the blocks located entirely or partially in the disputed area consist not only of seismic studies, but also of operations which are physically harmful to the continental shelf”.

• 569. According to Côte d’Ivoire, “Ghana was fully aware of the existence of a delimitation dispute, well before it commenced its activities in the disputed area” and “Ghana was fully informed of [Page 533] Côte d’Ivoire’s opposition to oil exploration activities’ being carried out in the disputed area”. Côte d’Ivoire argues that Ghana’s “activities potentially affect the sovereignty or sovereign rights of Côte d’Ivoire and run the risk of irreparable harm” and that “the internationally wrongful act on the part of Ghana is established even regardless of the delimitation to be decided”.

• 570. Côte d’Ivoire submits that the appropriate reparation for the violation of its sovereign rights has two aspects. First, in respect of “the wrongful act … of the gathering and analysis of exclusive information, restitutio in integrum is the most appropriate form of reparation”. Côte d’Ivoire notes the finding of the Special Chamber in its Order of 25 April 2015 “that ‘the exclusive right to access to information about the resources of the continental shelf is … among’ the sovereign rights”.

• 571. Second, Côte d’Ivoire submits that reparation by equivalence or compensation “should be envisaged both for the loss of hydrocarbon production and for any damage that Ghana’s activities may have caused to rocks and deposits”.

• 572. In its final submissions, Côte d’Ivoire requests the Special Chamber “to invite the Parties to carry out negotiations in order to reach agreement on the terms of the reparation due to Côte d’Ivoire”, and

  to state that, if they fail to reach an agreement within a period of 6 months as from the date of the Judgment to be delivered by the Special Chamber, said Chamber will determine those terms of reparation on the basis of additional written documents dealing with this subject alone.

• 573. In its final submissions, Ghana requests the Special Chamber to adjudge and declare that “Côte d’Ivoire’s claim alleging violation of … Côte d’Ivoire’s sovereign rights is rejected”. Invoking factual and legal grounds, Ghana denies that its activities have violated Côte d’Ivoire’s sovereign rights.

• 574. Ghana describes Côte d’Ivoire’s submission on the violation of sovereign rights as “unsupported by authority, principle or the evidence”. Ghana submits that “it can hardly be said that State A violates State B’s sovereign rights by undertaking activities in a maritime area which both States treated as belonging to State A, even if some of the area is later awarded to State B”.

• 575. According to Ghana, the propositions “that the sovereignty of a State entails exclusive sovereign rights over the State’s territory” and “that a judicial determination of a disputed boundary is declarative, not constitutive” do not support “the far-reaching conclusion that Côte d’Ivoire seeks to draw”.

• [Page 534] 576. Ghana considers that “as a general principle, [it] is not disputed” that a State’s sovereign rights “include exclusive rights to exploit the natural resources of the territorial sea, over which it has sovereignty, and to do so on its continental shelf, over which it has sovereign rights”. Ghana considers that this position “is reflected in paragraph 61 of the Order of 25 April 2015”.

• 577. In respect of the North Sea Continental Shelf cases relied on by Côte d’Ivoire, Ghana’s position is that

  there is a “considerable difference” between the proposition that … a State is not obliged to proclaim its rights over the continental shelf within 200 M (or territorial sea), and the proposition that a State can act inconsistently with such claimed rights and then assert them retrospectively—with financial consequences—over an area which it has belatedly declared to be in dispute.

• 578. Ghana describes the proposition that “a judicial determination of a disputed boundary is declarative, not constitutive” as “uncontroversial as a general principle” and states “that a disputed maritime area is not to be treated as terra nullius until a tribunal rules on the location of the maritime boundary”.

• 579. Ghana further argues:

  If … Articles 77, 81 and 193 of UNCLOS are automatically violated by any State which conducts activities in a disputed maritime area, then one would expect to see international courts and tribunals finding such violations in every boundary case in which such activities have been undertaken, yet none has ever done so.

• 580. Ghana maintains that the courts and tribunals referred to by Côte d’Ivoire in this context “have not treated maritime boundary awards as rendering the parties liable for activities in the area when it was disputed” and that they “have consistently declined to punish a State for good-faith use of territory which is ultimately awarded to its neighbour”.

• 581. Ghana submits that “even if there were … a rule against unilateral activity in a disputed area, that is not the sort of activity that we are dealing with here”. According to Ghana, its activities “in the relevant area are not, and have never been ‘unilateral’”, they “have been conducted openly and with Côte d’Ivoire’s cooperation”, “in accordance with a common understanding of a customary boundary”. Ghana further submits that “[u]ntil 2009, when Côte d’Ivoire proposed a new maritime boundary line, there was no ‘disputed area’”. Ghana contends that “it is very difficult for a State to say that its rights have been violated by things which another State has done with its consent”.

• [Page 535] 582. Regarding Côte d’Ivoire’s claim for restitutio in integrum for the violation of its sovereign rights, Ghana contends that Côte d’Ivoire “has failed to establish the existence of the right to information which it seeks to protect” and that there is “no legal basis for the Special Chamber to order Ghana to provide the very extensive list of information which Côte d’Ivoire now seeks”. While Ghana states that the Special Chamber considered the right to information to “be ‘plausibly’ among the rights of the coastal State over its continental shelf”, it notes “Côte d’Ivoire’s failure to cite any relevant authority in support of the existence of such a right”.

• 583. In respect of Côte d’Ivoire’s claim for compensation for the violation of its sovereign rights, Ghana states that “[t]he exploitation activities carried out by Ghana have proceeded for many years, with the knowledge and acquiescence of Côte d’Ivoire” and notes that “[t]he same or similar physical changes to the marine environment would take place if any part of the disputed area lay within the territory of Côte d’Ivoire”. According to Ghana, “[i]t would be absurd to compensate Côte d’Ivoire … for physical changes to the seabed brought about by oil production works which Côte d’Ivoire itself wants to pursue in the very same way”. Accordingly, Ghana submits that “[t]he only financial loss which Côte d’Ivoire will have suffered, if awarded any part of the disputed area, is the loss of net revenues derived from oil production in that area (having regard to the costs)”.

• 584. Ghana notes that Côte d’Ivoire has accepted that such issues should be reserved for negotiation between the Parties.

  * * *

• 585. The Special Chamber notes that the arguments advanced by the two Parties touch upon several distinct but interrelated factual and legal issues. As far as facts are concerned, the Parties disagree as to when Ghana should have been aware that a delimitation dispute with Côte d’Ivoire existed and, when it was aware, as to the scope of the disputed area. The Parties further disagree about the legal consequences of such knowledge. Although the Parties agree upon the nature of the rights of coastal States in respect of the continental shelf off their coast, they disagree about the consequences to be drawn therefrom. The Parties further agree upon the legal nature of a judgment on delimitation but again disagree on the consequences to be drawn therefrom in the present case. Finally, the Parties disagree on the manner in which the compensation claimed should be calculated. The Special Chamber will deal with each of these issues in turn as necessary.

• [Page 536] 586. The Special Chamber notes that, although Côte d’Ivoire informed Ghana of a delimitation dispute, the precise date when such information was provided remains unclear. It is not necessary for the Special Chamber to establish this date for the purposes of the present case. The Special Chamber also notes that over time Côte d’Ivoire suggested different methods of delimitation, the consequence of which was that the scope of the maritime area under dispute differed for each of the proposals. In February 2009, Côte d’Ivoire proposed a delimitation based on a meridian. In May 2010, it proposed a different meridian and, in November 2011, Côte d’Ivoire changed its position and advocated the application of the angle bisector method. The line developed in 2011 was again modified in May 2014. The application of these different methods of delimitation resulted in disputed areas the location and size of which differed.

• 587. However, the Special Chamber also notes Côte d’Ivoire’s statements that the hydrocarbon activities of Ghana in the disputed area had increased since 2009 and that Ghana had undertaken drilling in the TEN field from 26 January 2009 until 26 August 2014. The TEN field borders the blocks for mineral resource activities licensed by Côte d’Ivoire and is situated in all the maritime areas which Côte d’Ivoire had qualified as being disputed.

• 588. Therefore, the Special Chamber is of the view that Ghana, when carrying out hydrocarbon activities in the TEN field, was or should have been aware that such activities were taking place in an area also claimed by Côte d’Ivoire.

• 589. On the basis of this consideration, the Special Chamber must now establish whether hydrocarbon activities carried out by a State in a disputed area before the area in question has been delimited by adjudication may give rise to international responsibility when these activities are carried out in a part of the area attributed by the judgment to the other State.

• 590. The Special Chamber agrees with the statements of the two Parties that the sovereign rights which coastal States enjoy in respect of the continental shelves off their coasts are exclusive in nature and that coastal States have an entitlement to the continental shelves concerned without the need to make a relevant declaration. However, the Special Chamber disagrees with both Parties as to the meaning of a judgment on the delimitation of a continental shelf. The Parties both consider such a judgment only to be of a declaratory nature but they disagree as to the consequences to be drawn from such a qualification.

• 591. The Special Chamber emphasizes that in a case of overlap both States concerned have an entitlement to the relevant continental shelf [Page 537] on the basis of their relevant coasts. Only a decision on delimitation establishes which part of the continental shelf under dispute appertains to which of the claiming States. This means that the relevant judgment gives one entitlement priority over the other. Such a decision accordingly has a constitutive nature and cannot be qualified as merely declaratory.

• 592. In the view of the Special Chamber, the consequence of the above is that maritime activities undertaken by a State in an area of the continental shelf which has been attributed to another State by an international judgment cannot be considered to be in violation of the sovereign rights of the latter if those activities were carried out before the judgment was delivered and if the area concerned was the subject of claims made in good faith by both States.

• 593. In this context, the Special Chamber takes note of the convergent decision of the ICJ in Territorial and Maritime Dispute (Nicaragua v. Colombia) which stated:

  The Court observes that Nicaragua’s request for this declaration [concerning Colombia’s violation of Nicaragua’s rights in the disputed area] is made in the context of proceedings regarding a maritime boundary which had not been settled prior to the decision of the Court. The consequence of the Court’s Judgment is that the maritime boundary between Nicaragua and Colombia throughout the relevant area has now been delimited as between the Parties. In this regard, the Court observes that the Judgment does not attribute to Nicaragua the whole of the area which it claims and, on the contrary, attributes to Colombia part of the maritime spaces in respect of which Nicaragua seeks a declaration regarding access to natural resources. In this context, the Court considers that Nicaragua’s claim is unfounded.

  (Judgment, ICJ Reports 2012, p. 624, at p. 718, para. 250)

• 594. On the basis of the foregoing, the Special Chamber finds the argument advanced by Côte d’Ivoire that the hydrocarbon activities carried out by Ghana in the disputed area constitute a violation of the sovereign rights of Côte d’Ivoire is not sustainable, even assuming that some of those activities took place in areas attributed to Côte d’Ivoire by the present Judgment. Therefore, the Special Chamber finds that Ghana did not violate the sovereign rights of Côte d’Ivoire.

• 595. As a consequence of the above, the Special Chamber considers it unnecessary to deal with Ghana’s argument that Ghana’s hydrocarbon activities took place east of the “customary equidistance line” and therefore cannot engage international responsibility and were consented to by Côte d’Ivoire, since the Special Chamber has already established that this line has no legal relevance (see paras. 228 and 246 above).

D. Violation of article 83 of the Convention

• 596. The Special Chamber will now turn to the alleged violation of article 83 of the Convention. It notes that this claim by Côte d’Ivoire is based upon two different approaches, one invoking a violation of article 83, paragraph 1, and the other invoking article 83, paragraph 3, of the Convention.

• 597. Article 83 of the Convention reads:

  • 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.

  • 2. If no agreement can be reached within a reasonable period of time, the States concerned shall resort to the procedures provided for in Part xv.

  • 3. Pending agreement as provided for in paragraph 1, the States concerned, in a spirit of understanding and cooperation, shall make every effort to enter into provisional arrangements of a practical nature and, during this transitional period, not to jeopardize or hamper the reaching of the final agreement. Such arrangements shall be without prejudice to the final delimitation.

  • 4. Where there is an agreement in force between the States concerned, questions relating to the delimitation of the continental shelf shall be determined in accordance with the provisions of that agreement.

E. Alleged violation by Ghana of the provisional measures prescribed by the Special Chamber

• 635. In its final submissions, Côte d’Ivoire “requests the Special Chamber … to declare and adjudge that Ghana has violated the provisional measures prescribed by [the Special] Chamber by its Order of 25 April 2015” (hereinafter “the Order”). Côte d’Ivoire further requests the Special Chamber “by way of reparation, to declare that by failing to comply with the Order imposed on it, Ghana has committed an internationally wrongful act engaging its responsibility”.

• 636. According to Côte d’Ivoire, Ghana “has violated the Order … on at least two counts”. It specifies that, “[f]irst, Ghana has disregarded the provisional measure prohibiting it from performing any ‘new drilling’, prescribed in paragraph 108, sub-paragraph (1)(a)” of the Order. Côte d’Ivoire maintains that

  [t]he most reasonable interpretation of paragraph 108(1)(a) of the Order … leads to the observation that Ghana must ensure that no new drilling occurs in the disputed area, in the sense of any action consisting of crushing the rock, which was not ongoing as at 25 April 2015.

  It disputes Ghana’s “highly restrictive” interpretation of the obligations imposed on it by the measure prescribed by the Order, an interpretation according to which Ghana considers that this measure prohibits it solely from drilling new wells.

• 637. Côte d’Ivoire alleges that “the drilling activities have been continued in the TEN field” and that the stepping up of Ghana’s activities in the TEN block, where Ghana has authorized drilling to be carried out in order to ensure that the financial returns are obtained as quickly as possible, is worthy of note. It claims that the “reports on the activities of the two drilling rigs present in the disputed area refer to 15 activity campaigns … on the TEN field between 25 April 2015 and 30 September 2016”, including the drilling of well Nt07. Côte d’Ivoire adds that “[t]he second drilling phase on this well started on 13 July 2015 and ended on 5 August” and that “during that drilling campaign nearly 1,400 further metres’ depth of rock were drilled, within a period of 24 days of continuous drilling”.

• 638. Côte d’Ivoire adds that Ghana “has also disregarded its obligation to cooperate, prescribed as a provisional measure by the Special Chamber in paragraph 108, sub-paragraph (1)(e) of its Order”. It specifies that “the Agent of Côte d’Ivoire on three occasions requested the Agent of Ghana to send information concerning the activities carried out in the disputed area, so as to have confirmation that they [Page 547] were in conformity with the Order of the Special Chamber” and refers, in particular, to the letter of 27 July 2015 which the Agent of Côte d’Ivoire sent to the Agent of Ghana on this matter. Côte d’Ivoire adds that it “repeated this request … during a bilateral meeting held on 10 September 2015 in Accra, precisely on the subject of the steps taken to comply with the provisional measures”.

• 639. Côte d’Ivoire claims that Ghana nevertheless systematically refused to transmit to Côte d’Ivoire documents relating to the activities which it was carrying out in the disputed area, the reason being that it was neither required nor reasonably necessary to send them. It affirmed that Ghana “agreed to furnish these documents only after the matter had been referred to the President of the Special Chamber by Côte d’Ivoire and he had adopted a decision in this respect on 23 September 2016”.

• 640. Ghana, in its final submissions, requests the Special Chamber to “adjudge and declare that … Côte d’Ivoire’s claim alleging violation [by Ghana] of the Special Chamber’s Order of 25 April 2015 is rejected”.

• 641. Ghana maintains that it “has complied with its obligations under this part of the Order in full”.

• 642. Ghana declares “[that] it has ensured that there is no new drilling in the disputed area” and that the only activity undertaken by the operators was the work carried out on wells which had already been drilled, which was necessary for them to go into production. Ghana maintains that these activities are permitted by virtue of the Order. From its point of view, the interpretation of the Order by Côte d’Ivoire does not take into account the spirit and letter of the Order which clearly indicates, in particular in paragraphs 99 and 100, that Ghana “was not required to suspend all ongoing activities in respect of which drilling had already taken place, including, specifically, exploration or exploitation activities”.

• 643. As regards the TEN field, Ghana explains that “all of the wells were planned and approved by Ghana well before this claim was commenced” and that “[t]he idea suggested by Côte d’Ivoire that there has been an artificial acceleration of drilling of a new well in 2015 to try to defeat the Special Chamber is wholly unjustified”. Ghana underlines that “prior to the Order, in the course of its ordinary activities, Tullow had already drilled eleven wells, of which ten were to be used for first oil production”. According to Ghana, the eleventh well, Nt07, was to serve as “a water injector well for improving production” and it had been “drilled to a very substantial depth”. Ghana explains that “[w]ater injectors are important to ensure that there is adequate production and [Page 548] that the reservoir is properly maintained”. As regards well Nt07, it alleges that it already existed and was thus not, contrary to Côte d’Ivoire’s claim, newly drilled.

• 644. Ghana maintains that it had also taken “steps to ensure that maritime safety was not compromised by the continuation of the permitted activities in the disputed area” and that these

  were entirely appropriate safety measures of a kind taken by all States engaged in petroleum operations to protect other maritime users, as well as the marine environment and the relevant equipment, from damage which may be caused by a collision or unduly close approach of other vessels.

• 645. As regards its obligation to cooperate, Ghana considers that it has “complied with the Order and has engaged in extensive cooperation with and reporting to Côte d’Ivoire since the issuance of the Order”. It notes that it has

  continued its cooperation with Côte d’Ivoire, despite its firm belief that Côte d’Ivoire’s claim to the “disputed area” is an unfounded attempt to interfere with Ghana’s lawful use of its own territory, to its significant detriment.

• 646. Ghana affirms that “[a]ll of the questions raised in Côte d’Ivoire’s letter of July 2015 were addressed at a meeting attended by agents of both Parties and numerous specialist representatives in September 2015, and in the work undertaken subsequent to that meeting”. Ghana adds that, in some cases, Côte d’Ivoire had requested “far more information than was reasonably necessary to understand the nature of the activities in the disputed area”, including daily reports thereon as well as other information.

  * * *

• 647. As regards the question as to whether Ghana has violated the provisional measures prescribed by the Order of the Special Chamber, the Special Chamber notes that, pursuant to article 290 of the Convention, its Order for the prescription of provisional measures is obligatory in nature, creating legal obligations with which parties have to comply. In this regard, the Special Chamber draws attention to paragraph 6 of article 290, according to which “[t]he parties to the dispute shall comply promptly with any provisional measures prescribed under this article”.

• 648. The Special Chamber observes that, in its Counter-Memorial, Côte d’Ivoire alleged that “Ghana has violated points (a), (c) and (e) of the provision” of the Order. Sub-paragraph (1)(a), (c) and (e), of paragraph 108 of the Order reads as follows:

  [Page 549] For these reasons,

  The Special Chamber,

  • (1) Unanimously

    Prescribes, pending the final decision, the following provisional measures under article 290, paragraph 1, of the Convention:

    • (a) Ghana shall take all necessary steps to ensure that no new drilling either by Ghana or under its control takes place in the disputed area as defined in paragraph 60;

      …

    • (c) Ghana shall carry out strict and continuous monitoring of all activities undertaken by Ghana or with its authorization in the disputed area with a view to ensuring the prevention of serious harm to the marine environment;

      …

    • (e) The Parties shall pursue cooperation and refrain from any unilateral action that might lead to aggravating the dispute.

  (Dispute Concerning Delimitation of the Maritime Boundary between Ghana and Côte d’Ivoire in the Atlantic Ocean (Ghana/Côte d’Ivoire), Provisional Measures, Order of 25 April 2015, ITLOS Reports 2015, p. 146, at p. 166, para. 108)

• 649. The Special Chamber notes that, in its Rejoinder and during the oral proceedings, Côte d’Ivoire did not maintain the argument concerning subparagraph 1(c) of the operative part of the Order.

• 650. As regards the provisional measures requiring Ghana to ensure that “no new drilling takes place … in the disputed area”, the Special Chamber notes that drilling has been carried out by Ghana or under its control in the disputed area. However, it observes that during the oral proceedings Ghana explained that the only activities it had undertaken were “ongoing activities in respect of which drilling had already taken place” and that the purpose of these activities was to ensure the proper production and maintenance of the oil deposits. The Special Chamber further notes that Ghana indicated that it had taken the necessary steps in terms of maritime safety in order to protect other users of the sea and of the marine environment.

• 651. According to the information communicated to it, the Special Chamber notes, however, that drilling activities had been carried out by Ghana or under its control on wells already drilled. These drilling activities constitute “ongoing activities … for which drilling has already been carried out” and are covered by paragraphs 99 and 100 of its Order of 25 April 2015. These paragraphs read as follows:

  • [Page 550] 99. Considering that, in the view of the Special Chamber, the suspension of ongoing activities conducted by Ghana in respect of which drilling has already taken place would entail the risk of considerable financial loss to Ghana and its concessionaires and could also pose a serious danger to the marine environment resulting, in particular, from the deterioration of equipment;

  • 100. Considering that, in the view of the Special Chamber, an order suspending all exploration or exploitation activities conducted by or on behalf of Ghana in the disputed area, including activities in respect of which drilling has already taken place, would therefore cause prejudice to the rights claimed by Ghana and create an undue burden on it.

• 652. The Special Chamber therefore concludes that, pursuant to the Order, no “new drilling” by Ghana or under its control has been carried out in the disputed area.

• 653. As regards the provisional measure requiring the Parties to pursue their cooperation, the Special Chamber notes that Ghana has contributed to cooperation on several occasions.

• 654. The Special Chamber observes that, during a bilateral meeting held on 10 September 2015, Ghana, in response to the letter of 27 July 2015 to the Agent of Ghana from the Agent of Côte d’Ivoire, addressed the questions concerning the activities carried out in the disputed area.

• 655. It also observes that, in response to the letter from the President of the Special Chamber sent to the Parties on 23 September 2016 (see para. 41), on 14 October 2016, Ghana presented additional information concerning the activities carried out in the disputed area, in accordance with paragraph 108, subparagraph (2), of the Order for the prescription of provisional measures dated 25 April 2015. It notes that this additional information was transmitted to Côte d’Ivoire.

• 656. The Special Chamber observes, however, that Ghana did not immediately provide all the information requested by Côte d’Ivoire and that it did so only after the President of the Special Chamber requested it to comply by letter dated 23 September 2016. The Special Chamber nevertheless considers that such conduct cannot reasonably be considered to constitute a violation of the measures prescribed in the Order of 25 April 2015.

• 657. Therefore, the Special Chamber is of the opinion that Ghana continued to cooperate and communicated to Côte d’Ivoire the information relating to the activities carried out in the disputed area, pursuant to the Order.

• 658. In the light of the above, the Special Chamber finds that Ghana did not violate the Order of 25 April 2015 of the Special Chamber prescribing provisional measures.

F. Conclusion on responsibility

• 659. On the basis of the above considerations, the Special Chamber concludes that none of the activities of Ghana engages its international responsibility. Therefore, the Special Chamber considers that there is no need to address the question of reparation.