ABSTRACT
Pouring oil on to water used to be an acceptable method of preventing trouble: nowadays it is a source of international friction. Concessions to coastal State jurisdiction come gradually, by negotiation in international fora, subject to qualifications ensuring an equitable balance of interests. Applicable international law was enforceable by the flag State, generally on the vessel’s return to it, but there was until after World War II little law relating to preventing oil pollution. The Territorial Sea Convention limits the coastal State to taking ‘the necessary steps’ to prevent non-innocent passage therein, though requiring foreign ships to comply with its laws regulating, inter alia, transport and navigation. The High Seas Convention codified freedom of navigation thereon; ships remain subject only to the jurisdiction of their State of registration, whose flag they fly. The remaining weaknesses of the international legal system for enforcement of conventions to prevent oil pollution by vessels lie in the predominant position thereunder of the flag State.
