Throughout the various conferences addressing the law of the sea, states shaped and reshaped legal concepts relating to the oceans. They invented the ‘continental shelf’, ‘transit passage’, the ‘exclusive economic zone’, ‘archipelagic waters’ and the ‘seabed’. They reformulated the contiguous zone and fishing limits. And with a single stroke of a pen, they shrank the high seas by a third. Then, in 1994, just before the 1982 convention was about to enter into force, the UN General Assembly, prodded along by the United States, passed the ‘Implementation Agreement’, which amended the seabed regime set out within it. Now, over four decades after signature, new geopolitical forces will inevitably generate pressure for further changes to the law governing the sea.

This chapter will examine rules governing marine spaces beyond the limits of national jurisdiction, namely, the high seas and the Area. The high seas are essentially characterised by the principle of freedom of the seas, and order in the high seas is ensured primarily by the flag State. Thus, the principle of the exclusive jurisdiction of the flag State and its exceptions are key issues underlying international law governing the high seas. However, the Area is governed by the principle of the common heritage of mankind. This principle is innovative because it may bring new viewpoints beyond the State-to-State perspective in the law of the sea. Against that background, this chapter will discuss in particular the following issues: (1) the principle of freedom of the high seas, (2) the principle of the exclusive jurisdiction of the high seas, (3) the problems associated with flags of convenience, (4) the peacetime exceptions to the principle of the exclusive jurisdiction of the flag State on the high seas, (5) the raison dtre of the principle of the common heritage of mankind, and (6) the 1994 Implementation Agreement