The Practical Realization of the Continental Shelf Limit

Abstract

The first steps in establishing the case for a possible continental shelf claim beyond 200 nautical miles (M) were covered in the previous chapter. The requirement for an initial assessment of existing data and information before proceeding with the practical stage of new data acquisition and assessment to determine the actual legal limit of the continental margin is clear. This chapter deals with the three possible cases: (case A) no extended continental shelf, (case B) foot of the slope plus 60 M, and (case C) limits based on the foot of the slope and sediment thickness. Finally, the chapter deals with the delimitation of the two possible outer limit lines that are required to be implemented by coastal States, provided their continental margins extend up to or beyond those two limiting lines. Figure 17.1 illustrates how those limits could be combined to form a coastal State's continental shelf limit. . . . The continental shelf of a coastal State comprises the sea-bed and subsoil of the submarine areas that extend beyond its territorial sea throughout the natural prolongation of its land territory to the outer edge of the continental margin, or to a distance of 200 nautical miles (M) from the baselines from which the breadth of the territorial sea is measured where the outer edge of the continental margin does not extend up to that distance. . . . This provision, in principle, provides every coastal State with a continental shelf extending at least 200 M seaward. In practice, there are a number of constraints which result in the situation where a coastal State's entitlement to a continental shelf does not extend beyond 200 M. Let us therefore consider the procedure that each coastal State should follow to enable it to reach this conclusion. If a coastal State's entitlement to a continental shelf does not extend beyond 200 M measured from the territorial sea baseline, it can be assumed that the maritime zone calculated out to that distance will be subsumed within an exclusive economic zone regime, provided the coastal State claims such a zone, under part V of UNCLOS.