United Nations Convention on the Law of the Sea

The United Nations Convention on the Law of the Sea, adopted in 1982 and entering into force in 1994, is the constitutional framework for all activities conducted in and on the ocean. It defines the maritime zones — internal waters, territorial sea, contiguous zone, exclusive economic zone, continental shelf, and the high seas — and sets out the rights and duties of states and ships within each zone. It establishes the principle of freedom of navigation on the high seas whilst balancing coastal state rights to regulate their adjacent waters. For a master on an ocean voyage, UNCLOS determines the legal regime applicable to the vessel at any given position. Within the territorial sea (up to 12 nautical miles from the baseline), foreign ships have the right of innocent passage — transit that is continuous and expeditious and not prejudicial to coastal state peace or security. In the EEZ (up to 200 nautical miles), the coastal state has sovereign rights over natural resources but ships retain freedom of navigation. UNCLOS also establishes the duty to render assistance to persons in distress at sea — a positive obligation on the master of any vessel that is in a position to assist — and creates the framework for SAR co-operation. The Convention's dispute settlement mechanisms, including the International Tribunal for the Law of the Sea (ITLOS), provide a means of resolving flag state disagreements over enforcement actions.