The United Nations Convention on the Law of the Sea (UNCLOS) is a comprehensive international treaty, often called the "constitution for the oceans," that establishes a legal framework for all marine and maritime activities. The Convention was signed on December 10, 1982, and entered into force on November 16, 1994, following the Third UN Conference on the Law of the Sea (UNCLOS III) held between 1973 and 1982. It was created to replace the older, fragmented concept of "freedom of the seas" and the four 1958 Geneva Conventions, solving the problem of escalating, unilateral maritime claims by nations seeking to control resources and manage pollution.
The Convention, which contains over 300 Articles grouped into 17 Parts, works by defining distinct maritime zones. A coastal state's sovereignty extends up to 12 nautical miles in its Territorial Sea, subject only to the right of innocent passage for foreign vessels. The state has exclusive rights over all natural resources, both living and non-living, within its Exclusive Economic Zone (EEZ), which extends up to 200 nautical miles from the baseline. The area beyond national jurisdiction, known as the High Seas, is open to all states.
UNCLOS established three key institutions: the International Tribunal for the Law of the Sea (ITLOS) to adjudicate disputes, the International Seabed Authority (ISA) to regulate mineral activities in the deep seabed (The Area), and the Commission on the Limits of the Continental Shelf (CLCS). The original treaty's Part XI was modified by the 1994 Agreement to address concerns regarding deep seabed mining. A significant recent development is the Agreement on Biodiversity Beyond National Jurisdiction (BBNJ Agreement), or High Seas Treaty, finalized in March 2023 and adopted in June 2023, which addresses the conservation of marine life in the High Seas, filling a gap in the original Convention.