The International Law of the Sea is a specialist topic within public international law concerning the control and use of the sea. It has a long history in customary international law, though in more recent times much of it has been codified in the 1982 United Nations Convention on the Law of the Sea (UNCLOS) and related treaties. This module provides the important knowledge and understanding of the non-navigational rights and duties of coastal States and other States in each of the maritime zones in the law of the sea, along with an in depth exposition of the political, economic and military reasons underlying the present rules in UNCLOS. It examines the challenges from the changing uses of the sea and the sorts of adaptive rules that might in future be needed, as well as the dispute settlement system of UNCLOS and its variants in related treaties. In placing its main focus on the zonal divisions of the world’s oceans (exclusive economic zone, high seas, continental shelf, etc), the module considers moreover key thematic/sectoral issues in the law of the sea over the last half century, e.g., fisheries, deep seabed mining and dispute settlement.