Part II: Analysis of Dispute Concerning Delimitation of the Maritime Boundary between Ghana and Côte d’Ivoire in the Atlantic Ocean

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An overview of the Ghana/Côte d’Ivoire judgment is provided in the first part of this post. The purpose of this second part is to highlight issues of practical significance which flow from the judgment.

In two important ways, the Ghana/Côte d’Ivoire judgment has demonstrated the functionality of dispute resolution processes under Part XV of UNCLOS, both in the context of maritime delimitation disputes and more generally.

Consistency with international delimitation jurisprudence

First, the ITLOS Special Chamber evidenced a desire to contribute to the development of consistent delimitation jurisprudence, and confirmed that the ‘equidistance/relevant circumstances method’ is now standard in a delimitation process – regardless of whether the coasts of claiming States parties are opposite or adjacent to one another. Importantly, it adhered to the three-step methodology identified and employed by the International Court of Justice (ICJ) in Black Sea. It did so by drawing a provisional equidistance line between the relevant coasts, considering the factors which might warrant adjustment of that line, and then applying an ex-post facto (dis)proportionality test to verify that the delimitation line was equitable. Notably, the Special Chamber maintained consistency with recent maritime delimitation jurisprudence by underscoring the primacy of criteria associated with coastal geography (concavity, coastal length, etc.) and ignoring factors related to offshore oil activities or the presence of seabed resources in the relevant area.

Also in accordance with international judicial practice is the Special Chamber’s decision to uphold its own jurisdiction [paras 76-88; 482-495; 545-554] and delimit the outer continental shelf areas beyond 200nm, notwithstanding the absence of recommendations from the Commission on the Limits of the Continental Shelf. Other courts and tribunals have indicated that a lack of relevant Commission recommendations does not deprive them of the competence to determine delimitations. For example, in Bangladesh/Myanmar, ITLOS upheld its jurisdiction over outer continental shelf-designations, and went on to effect delimitation.

States’ obligations under UNCLOS

Second, the Ghana/Côte d’Ivoire judgment provides valuable analysis of States’ UNCLOS obligations with regard to unilateral petroleum activities in disputed maritime areas. It indicates that, prior to an international judgment attributing the disputed area to the complaining State, the initiating State’s unilateral actions on the EEZ or continental shelf of that area will not have breached the former’s sovereign rights if the latter can show that it acted in good faith and with the honest belief that those areas were within its territory [para 592]. Consequently, the initiating State’s international responsibility will not be engaged; there will be no duty to provide reparations for harm caused.

It is suggested here that the Special Chamber’s reasoning might spell trouble for other maritime boundary disputes, especially in oil-rich regions. If misinterpreted, the finding that an initiating State bears no international responsibility for alleged violations of the other claiming State’s alleged rights could encourage more unilateralism in areas with seabed resources. A claiming State may seek to move faster towards oil development and production in the disputed area, with a view to creating a fait accompli which renders nugatory or of no effect the final decision of a court or tribunal.

This raises a question of practical significance: What would be the most meaningful remedy for a State pursuing legal action against another State’s unilateral oil activities in the disputed maritime area? The Special Chamber’s reasoning suggests that the most practical response is to trigger compulsory resolution under Part XV of UNCLOS and request provisional measures as a means of restraining oil activities. With regard to provisional measures in the context of unilateral seismic exploration surveys in disputed maritime areas, the ICJ held in Aegean Sea (a pre-UNCLOS case of 1976) that seismic operations may constitute a violation of the ‘sovereign right of a State to explore its natural resources’ [Aegean Sea (1976) paras 30-33]. However, the ICJ concluded that provisional measures were not justified, since seismic surveys are unlikely to cause irreparable harm to the rights at issue [Aegean Sea (1976) paras 30-33]. The Special Chamber maintained consistency with this judicial practice: it required Ghana to refrain from disclosing exploration data to private-sector companies to the detriment of Côte d’Ivoire and to suspend the drilling of new wells in the disputed area [Order of 25 April 2015, para 108(b)], but it did not order Ghana to suspend all ongoing or future seismic surveys. Therefore, in the absence of agreed maritime boundaries, unilateral seismic surveys do not immediately raise questions of irreparable infringement of the claimant party’s rights; nor do they justify the prescription of interim protection measures (such as immediate cessation of seismic activities). Presumably, this is due to the perception that seismic testing on seabed, subsoil and superjacent waters has a lower intrusiveness threshold than the drilling of wells.

Nevertheless, it has been established that any form of drilling causes irreparable and irreversible damage to the seabed. According to the Order of 25 April 2015, no form of compensation could ever restore such damage [Order of 25 April 2015, para 90]. In this respect, the Special Chamber’s reasoning closely followed the decision of the Guyana/Suriname Tribunal, which considered that ‘activities of the kind that lead to a permanent physical change, such as exploitation of oil and gas reserves … may hamper or jeopardise the reaching of a final agreement on delimitation’ [Guyana/Suriname (2007) paras 267-470]. Therefore, drilling will justify the prescription of provisional measures of protection, on the basis that this activity so modifies the continental shelf’s physical characteristics, that irreparable prejudice is caused and financial compensation can never be sufficient.

Also important in this regard is the Special Chamber’s decision to prescribe the suspension of new drilling through its Order. Ghana’s oilfield projects were unaffected if already in the development and production phases. This finding suggests that the right to interim protection for a complaining State could be weakened by the other claiming State’s advanced petroleum development operations in the disputed area. Indeed, if such operations have progressed to the point of drilling, an adjudicating body may find, as the Special Chamber did, that suspension of all operations poses an ‘undue burden’ on the initiating party and risks harming the marine environment through ‘deterioration of equipment’ [Order of 25 April 2015, paras 99-100]. Thus, when considering an application for provisional measures, the court or tribunal must inevitably consider the preservation of both States’ sovereign and economic rights. This may be adjudged in its final judgment on merits.

If the above analysis is correct, then at which stage of unilateral oil and gas operations should the complaining State seek provisional protection measures? Previous judgments of international tribunals, along with the relevant academic literature, suggest that provisional measures are legally and factually justified only in relation to drilling (which necessarily has a higher impact threshold than seismic surveys). However, the fact remains that any drilling – be it exploratory, appraisal- or development-related – causes irreversible damage and permanent modification of the continental shelf, which no form of compensation can remedy. In such circumstances, provisional measures would not preserve the parties’ alleged rights pendente litis. It appears, therefore, that the optimum moment to seek interim protection is before commencement of drilling operations. If the complaining State received no pre-drilling notice from the initiating State, it could invoke this factor during a trial on merits as a violation of the latter’s due diligence obligations under Articles 74(3) and 83(3) of UNCLOS. Inevitably, however, this would never restore the continental shelf.

Effect of maritime delimitation disputes on oil projects’ profitability

Finally, the Ghana/Côte d’Ivoire case demonstrates that maritime delimitation disputes may adversely affect the profitability of oil and gas discoveries. There is no doubting the present dispute’s economic impact on Ghana and its concessionaries. Ghana had approved development of the TEN oilfields in 2013, even though the location of its maritime boundary with Côte d’Ivoire remained contested. As discussed, the Special Chamber did not order full suspension of the TEN fields (which had already advanced to 50 percent completion-stage, with over 2 billion USD invested by Tullow Oil and other commissionaires). Nonetheless, it ordered Ghana to refrain from drilling additional wells in the disputed maritime areas – including the TEN fields – until full resolution of the dispute. Thus, the Ghanaian concessionaries, having already drilled ten wells, were unable to drill the further fourteen required for full development of the oilfield. The rate of oil production significantly decreased.

In addition, once a reservoir has commenced production, additional wells are often required in order to maintain pressure and achieve necessary production rates. Loss of petroleum revenue is further incurred if there can be no drilling of new wells required for maintenance of pressure. This scenario played out in Ghana/Côte d’Ivoire when Côte d’Ivoire considered the eleventh well (Nt07) drilled in TEN to constitute a violation of the Order’s moratorium on new drilling. However, the Special Chamber accepted Ghana’s argument that the well did not constitute new drilling; it was required as a water-injector for improving production of existing wells.


The ITLOS Special Chamber’s judgment in Ghana/Côte d’Ivoire came down overwhelmingly in favour of a single multi-purpose boundary, both within and beyond the 200nm limit, based on the principle of equidistance. It refuted the existence of a tacit agreement as to the maritime boundary, but upheld an unadjusted equidistance boundary line favouring Ghana. Thus, the location of all ongoing oilfield-development projects in the area in question remained under Ghana’s control and jurisdiction. The judgment illuminated the application of the three-stage methodological approach to maritime delimitation in adjacent geographical situations, thus enriching the doctrine of maritime boundary delimitation within a successful body of law developed by the ICJ and other international tribunals. At the same time, and in view of the Special Chamber’s Provisional Measures Order of 2015, the legal reasoning and conclusions of the judgment are significant, in that they shed light on States’ rights and obligations under UNCLOS in respect of undelimited maritime areas, and also on the potential to respond meaningfully to unilateral, resource-related activities in disputed waters through recourse to provisional measures of protection.

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Nicholas A. Ioannides says

October 20, 2017

Dear Con and Elizabeth,

many thanks for this interesting and thorough post.

I agree with your commentary on the judgment and I'd like to elaborate on a highly problematic, in my view, finding of the Special Chamber, namely the fact that there was no violation of Article 83(3) LOSC.

To begin with, an obligation to refrain from activities detrimental to a state's sovereign rights should be distinguished from the self-restraint/due diligence duties stipulated in Articles 74(3) and 83(3) LOSC for it is not necessary to have a violation of sovereign rights in order to determine that there is a breach of the aforementioned provisions.

Consequently, irrespective of the fact that the Chamber found no violation of the Ivorian sovereign rights, it should have resolved that unilateral drillings performed by Ghana in an undelimited/disputed area clearly constituted a circumvention of the obligation to refrain from activities that might cause an irreparable damage to the seabed and might jeopardize or hamper the reaching of the final agreement according to Article 83(3) LOSC.

Judge Paik in his Separate Opinion attempted to clarify these issues and highlighted the risks such finding might entail with respect to other regions in the world.

Let's hope that subsequent judgments addressing this matter will not follow this approach, which seriously undermines the core of the said provisions.

Constantinos Yiallourides says

October 21, 2017

Dear Nicholas

Many thanks for your comment.

Indeed, the Special Chamber could have done more to clarify this crucial issue. Unilateral drilling in disputed maritime areas should, at face value, be in breach of the due diligence obligations provided for in Articles 74(3) and 83(3) of UNCLOS.

A possible justification of the Special Chamber's approach is that the judges were more concerned with the determination of the maritime boundary between the parties and with the facilitation of the speedy implementation of the ruling without triggering a renewed round of disputation concerning the calculation of compensation due to Côte d'Ivoire and without burdening Ghana (the prevailing party) with additional costs.

On a positive note, the Special Chamber’s finding that Côte d’Ivoire never requested Ghana to enter into provisional arrangements of practical nature, hence Côte d’Ivoire was barred from claiming that Ghana had violated its obligations under Article 83(3) of UNCLOS ‘to make every effort’ to enter into such arrangements, means that States involved in maritime boundary disputes are prompted to seek such provisional arrangements as opposed to unilateral actions.