The International Law of Maritime Boundary Delimitation

The law of the sea, in its essence, divides the seas into zones and specifies the rights and duties of states and ships flying their flags in those zones. Now that states are claiming extensive seaward jurisdiction both on the continental shelf and in the water column, attention has begun to shift from delimiting continental shelf boundaries or economic zone boundaries to the delimitation of a single maritime boundary which would serve both purposes. There are significant legal differences between the delimitation of a single maritime boundary and the delimitation of either a continental shelf boundary or an exclusive economic zone boundary. The legal criteria developed for shelf delimitation focus on geological and geographical factors, while the criteria relevant to the exclusive economic zone, although not very well developed, may be regarded as also encompassing historic usage and economic considerations. This Article examines the principles and rules of international law applicable to the delimitation of a single maritime boundary. There is no international agreement in force governing the delimitation of a single maritime boundary. Although many nations are parties to the Convention on the Continental Shelf, that Convention cannot directly provide a rule, even for states that are parties, because its delimitation provision relates only to the continental shelf and not to a single maritime boundary. And there is no agreement in force concerning the delimitation of exclusive economic zones. Thus, lacking any binding conventional law, recourse must be made to the principles and rules of customary international law.