As discussed in previous chapters, in the international law of the sea, human activities in the ocean are regulated according to multiple jurisdictional zones. Thus the spatial distribution of jurisdiction of States is the foundation of oceans governance. In determining the spatial extent of coastal State jurisdiction, a question that may arise is the situation where the jurisdiction of two or more coastal States overlaps. In this case, delimitation of the overlapping marine spaces is at issue. It will deal with rules of international law with regard to maritime delimitation. This chapter will focus mainly on the following issues:
The spatial ambit of coastal State jurisdiction over marine spaces in the law of the sea is, in principle, defined on the basis of distance from the coast. In this regard, a question which may arise is how it is possible to delimit marine spaces where the jurisdictions of two or more coastal States overlap. Without rules on maritime delimitation in spaces where coastal State jurisdictions overlap, coastal States cannot enjoy the legal uses of maritime spaces effectively. Hence the law of maritime delimitation is of paramount importance in the law of the sea. In this regard, particular attention must be drawn to two issues.