The 1958 Geneva Conventions
Concerning the delimitation of the territorial seas, Article 12(1) of the TSC provides the triple rule of ‘agreement – equidistance (median line) – special circumstances':
Where the coasts of two States are opposite or adjacent to each other, neither of the two States is entitled, failing agreement between them to the contrary, to extend its territorial sea beyond the median line every point of which is equidistant from the nearest points on the baselines from which the breadth of the territorial seas of each of the two States is measured. The provisions of this paragraph shall 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 with this provision.
That triple rule can also be seen in Article 6 of the 1958 Convention on the Continental Shelf:
- Where the same continental shelf is adjacent to the territories of two or more States whose coasts are opposite each other, the boundary of the continental shelf appertaining to such States shall be determined by agreement between them. In the absence of agreement, and unless another boundary line is justified by special circumstances, the boundary is the median line, every point of which is equidistant from the nearest point of the baselines from which the breadth of the territorial sea of each State is measured.
- Where the same continental shelf is adjacent to the territories of two adjacent States, the boundary of the continental shelf shall be determined by agreement between them. In the absence of agreement, and unless another boundary line is justified by special circumstances, the boundary shall be determined by application of the principle of equidistance from the nearest point of the baselines from which the breadth of the territorial sea of each State is measured.
The triple rule calls for three comments.
First, one may wonder whether the reference to ‘agreement' could have been omitted as self-evident. As explained earlier, however, maritime delimitation is not a unilateral act. Accordingly, the reference to ‘agreement' may be at least useful to highlight the international character of maritime delimitation.
Second, a question arises with regard to the relationship between the element of ‘equidistance' and that of ‘special circumstances'. Provided that there is a hierarchy between these two elements, it may be possible to interpret equidistance as a principle and special circumstances as an exception, or, by contrast, special circumstances as a principle and equidistance as an exception. Should there be no hierarchy in those elements, equidistance and special circumstances can be regarded as one combined rule. As will be seen, the Court of Arbitration in the 1977 Anglo-French Continental Shelf case adopted this interpretation. In any case, it is difficult to find an authoritative answer in the framework of the Geneva Conventions.
The third issue concerns the concept of special circumstances, which is intended to avoid inequitable results from a mechanical application of the equidistance method. Nonetheless, the Geneva Conventions do not give a clear meaning for special circumstances. Hence, the specifics of special circumstances must be clarified through the development of jurisprudence and State practice in the field of maritime delimitation.
With regard to delimitation of the contiguous zone, Article 24(3) of the TSC provides a delimitation rule different from that governing the territorial sea and the continental shelf:
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 contiguous zone beyond the median line every point of which is equidistant from the nearest points on the baselines from which the breadth of the territorial sea of the two States is measured.
It follows that the pure equidistance method is applicable to the delimitation of contiguous zones. The omission of any reference to special circumstances is likely to be explained by the limited powers attributed to coastal States in such zones. The TSC contains no rule relating to the delimitation of internal waters. Considering that coastal States possess even more extensive powers in their internal waters than in their territorial sea, it appears to be possible to apply, by analogy or a fortiori, the same triple rule.
The 1982 UN Convention on the Law of the Sea
The LOSC differs from the 1958 Geneva Conventions in three respects.
First, the law applicable to the continental shelf was separated from that of territorial sea delimitation. While, under Article 15 of the LOSC, the delimitation of the territorial sea is governed by the traditional triple rule, the delimitation of the continental shelf follows a different rule.
Second, the delimitation of the contiguous zone is no longer mentioned in the text of the LOSC. Consequently, the rule applicable to the contiguous zone became unclear.
Third, Articles 74(1) and 83(1) of the LOSC formulate identical rules for the delimitation of the continental shelf and of the EEZ:
The delimitation of the exclusive economic zone [the continental shelf] between States with opposite and 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.
In the drafting of these provisions, there was disagreement between the supporters of ‘equidistance' and the supporters of ‘equitable principles'. The confrontation between the two groups was also linked to another difficult issue concerning peaceful settlement of disputes. While the supporters of ‘equidistance' were, as part of the package, in favour of establishing a compulsory, third-party system for the settlement of delimitation disputes, the supporters of ‘equitable principles' generally rejected the idea of compulsory judicial procedures. Owing to the confrontation between the two schools of thought, as late as one year before the adoption of the LOSC, no agreement had yet been reached with respect to the rule applicable to the delimitation of the EEZ and to the continental shelf. In order to break this deadlock, President Koh proposed a draft article which would bring about a compromise and, on 28 August 1981, the draft was incorporated into the Draft Convention. With a few modifications suggested by the Drafting Committee and approved by the Plenary Conference on 24 September 1982, the texts became, finally, Articles 74(1) and 83(1) of the LOSC. The ICJ has recognised that the provisions reflect customary international law.
These provisions require four observations.
First, Articles 74(1) and 83(1) omit any reference to a method of delimitation. In the absence of any method of delimitation, these provisions are likely to remain meaningless in specific situations. As will be seen, however, the interpretation of Articles 74(1) and 83(1) has changed through the development of jurisprudence relating to maritime delimitations. Currently international courts and tribunals take the view that the equidistance method is incorporated into these provisions.
Second, the concept of ‘equitable solution' is highly obscure. Hence this reference may be too vague to be very useful.
Third, it appears that the reference to Article 38 of the Statute of the ICJ as a whole is not of much use in determining the applicable law because Article 38 simply enumerates the sources of international law. Furthermore, decisions ex aequo et bono, i.e. extra-legal considerations set out in Article 38(2), seem to be less relevant. There is scope to argue that the references in Articles 74 and 83 should have been limited to Article 38(1).
Fourth, Article 311(1) of the LOSC stipulates that it shall prevail, as between States Parties, over the 1958 Geneva Conventions. Article 311(5) further provides that ‘this Article does not affect international agreements expressly permitted or preserved by other Articles of this Convention'. This provision is applicable to Article 6 of the Geneva Convention on the Continental Shelf, since Article 83 of the LOSC refers to Article 38 of the ICJ Statute. It would follow that Article 6 of the Geneva Convention applies between Parties to both the Geneva Convention and the LOSC.