Maritime delimitation presupposes an area of overlapping entitlements. Instead of focusing solely on the geomorphological and geological elements of the entitlement, this chapter surveys the State practice in order to contextualize the determination of overlapping entitlements to the continental shelf beyond 200 nm. Factors including the outer limits of the continental shelf, maritime delimitation within 200 nm, and the existence of multiple claims to the same continental shelf beyond 200 nm may play out in the determination of the overlapping entitlements to the continental shelf beyond 200 nm. Moreover, two scenarios wherein the existence of overlapping entitlements is doubtful are also examined. The first concerns the situation where two different parties invoke the two continental shelf criteria under Article 76 of the United Nations Convention on the Law of the Sea in a confined maritime area, which underlies the disputes of the Nicaragua v. Colombia cases. The other concerns the "zone-locked" scenario, in which a State’s access to the continental shelf beyond 200 nm is closed off by a maritime boundary within 200 nm.

This chapter discusses in detail the establishment of the entitlement to the continental shelf beyond 200 nautical miles under the United Nations Convention on the Law of the Sea. The meaning of natural prolongation, which is historically significant yet nebulous, has been transformed by Article 76, and its interpretation has to be examined in the context of application of Article 76 by coastal States and the Commission on the Limits of the Continental Shelf. The Bangladesh/Myanmar case clarified the meaning of natural prolongation, but its reasoning fell short of giving the notion any effect as a treaty term. In addition, other elements constitutive of the entitlement to the continental shelf beyond 200 nm, including the foot of the continental slope, the outer limits of the continental shelf, and the coasts are analyzed and their role in the process clarified.

This chapter explains the legal uncertainties arising in the continental shelf delimitation beyond 200 nautical miles. Given the special characters of the entitlement to the continental shelf beyond 200 nm in terms of its substantive, procedural, and institutional attributes, a great measure of uncertainty is introduced into the delimitation of the extended maritime areas, in particular with regard to the competence of international courts and tribunals and the applicable delimitation methodology. Clarification and refinement of these issues are vital for the pursuit of an equitable solution to maritime boundary-making and the stability of the law of maritime delimitation.