The United Nations Convention on the Law of the Sea (UNCLOS), also called the Law of the Sea Convention or the Law of the Sea Treaty, is an international treaty that establishes a legal framework for all marine and maritime activities. As of October 2024, 169 sovereign states and the European Union are parties to the convention. Some states have refused to recognise the convention. The convention resulted from the third United Nations Conference on the Law of the Sea (UNCLOS III), which took place between 1973 and 1982. UNCLOS replaced the four treaties of the 1958 Convention on the High Seas. UNCLOS came into force in 1994, a year after Guyana became the 60th nation to ratify the treaty. In 2023, agreement was reached on a High Seas Treaty to be added as an instrument of the convention, to protect ocean life in international waters. This would provide measures including marine protected areas and environmental impact assessments. While the secretary-general of the United Nations receives instruments of ratification and accession and the UN provides support for meetings of states party to the convention, the United Nations Secretariat has no direct operational role in the implementation of the convention. A UN specialized agency, the International Maritime Organization, does play a role, however, as do other bodies such as the International Whaling Commission and the International Seabed Authority (ISA), which was established by the convention itself.
Background United Nations Convention on the Law of the Sea replaces the older "freedom of the seas" concept, dating from the 17th century. According to this concept, national rights were limited to a specified belt of water extending from a nation's coastlines, usually 3 nautical miles (5.6 km; 3.5 mi) (three-mile limit), according to the "cannon shot" rule developed by the Dutch jurist Cornelius van Bynkershoek. All waters beyond national boundaries were considered international waters: free to all nations, but belonging to none of them (the mare liberum principle propounded by Hugo Grotius). In the early 20th century, some nations expressed their desire to extend national claims: to include mineral resources, to protect fish stocks, and to provide the means to enforce pollution controls. The League of Nations called a 1930 conference at The Hague, but no agreements resulted. Using the customary international-law principle of a nation's right to protect its natural resources, Harry S. Truman in 1945 extended United States control to all the natural resources of its continental shelf. Other nations were quick to follow suit. Between 1946 and 1950, Chile, Peru, and Ecuador extended their rights to a distance of 200 nautical miles (370 km; 230 mi) to cover their Humboldt Current fishing grounds. Other nations extended their territorial seas to 12 nautical miles (22 km; 14 mi). By 1967, only 25 nations still used the old three nautical mile limit, while 66 nations had set a 12-nautical-mile (22 km) territorial limit and eight had set a 200-nautical-mile (370 km) limit. As of 15 July 2011, only Jordan still uses the 3-mile (4.8 km) limit. That limit is also used in certain Australian islands, an area of Belize, some Japanese straits, certain areas of Papua New Guinea, and a few British Overseas Territories, such as Gibraltar. UNCLOS does not deal with matters of territorial disputes or to resolve issues of sovereignty, as that field is governed by rules of customary international law on the acquisition and loss of territory. The United Nations Sustainable Development Goal 14 has a target regarding conservative and sustainable use of oceans and their resources in line with UNCLOS legal framework.
UNCLOS I
In 1958, the United Nations held its first Conference on the Law of the Sea (UNCLOS I) at Geneva, Switzerland. UNCLOS I resulted in four treaties concluded in 1958:
Convention on the Territorial Sea and Contiguous Zone, entry into force: 10 September 1964 Convention on the Continental Shelf, entry into force: 10 June 1964 Convention on the High Seas, entry into force: 30 September 1962 Convention on Fishing and Conservation of Living Resources of the High Seas, entry into force: 20 March 1966 Although UNCLOS I was considered a success, it left open the important issue of breadth of territorial waters.
UNCLOS II In 1960, the United Nations held the second Conference on the Law of the Sea ("UNCLOS II"); however, the six-week Geneva conference did not result in any new agreements. Generally speaking, developing nations and third world countries participated only as clients, allies, or dependents of the United States or the Soviet Union, with no significant voice of their own.
UNCLOS III
The issue of varying claims of territorial waters was raised in the UN in 1967 by Arvid Pardo of Malta, and in 1973 the Third United Nations Conference on the Law of the Sea convened in New York. In an attempt to reduce the possibility of groups of nation-states dominating the negotiations, the conference used a consensus process rather than majority vote. With more than 160 nations participating, the conference lasted until 1982. The resulting convention came into force on 16 November 1994, one year after the 60th state, Guyana, ratified the treaty. The convention introduced a number of provisions. The most significant issues covered were setting limits, navigation, archipelagic status and transit regimes, exclusive economic zones (EEZs), continental shelf jurisdiction, deep seabed mining, the exploitation regime, protection of the marine environment, scientific research, and settlement of disputes. The convention set the limit of various areas, measured from a carefully defined baseline. (Normally, a sea baseline follows the low-water line, but when the coastline is deeply indented, has fringing islands or is highly unstable, straight baselines may be used.) The areas are as follows:
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