Constraining the Continental Shelf beyond 200 Nautical Miles in Maritime Delimitation Cases

Recent international jurisprudence reveals a tendency to constrain the continental shelf beyond 200 nautical miles (NM) in two principal respects. First, in relation to entitlement, courts have progressively limited the role of natural prolongation, treating it as subordinate to, or loosely applying it alongside, the distance criterion. This interpretation narrows the conditions under which a State may establish rights beyond 200 NM, thereby constraining the substantive scope of entitlement envisaged by Article 76 of the United Nations Convention on the Law of the Sea (UNCLOS) and the practice of the Commission on the Limits of the Continental Shelf. Second, regarding delimitation, judicial bodies have relied on the notion of a single continental shelf to extend the same equitable boundary line used within 200 NM seaward, effectively subordinating the outer shelf to the inner shelf. These developments restrict both the legal and spatial reach of outer continental shelf claims, reshaping the interpretation of the continental shelf beyond 200 NM in ways that appear increasingly difficult to reconcile with the natural prolongation-based framework established under Article 76 UNCLOS.