The LOS was needed due to the weakness of the older 'freedom of the seas' concept, dating from the 17th century: national rights were limited to a specified belt of water extending from a nation's coastlines, usually 3 miles (4.8 km) from the 'cannon shot' rule. All water beyond national boundaries was considered international waters- free to all nations but belonging to none of them.
Into the 20th century many nations expressed a need to extend national claims: to include mineral resources, to protect fish stocks and to have the means to enforce pollution controls. The first nation to undermine the 'freedom of the seas' was the USA, in 1945 President Truman unilaterally extended his nation's control to cover all the natural resources of their continental shelf. Other nations were quick to emulate the USA, in 1946-1950 Argentina, Chile, Peru and Ecuador all extended their sovereign rights to cover a 200 mile (320 km) area - so as to cover their Humboldt Current fishing grounds. Other nations extended their territorial seas to 12 miles (19 km). By 1967 only twenty-five nations still used the old three mile limit, 66 nations had set a 12 mile territorial limit and eight had set a 200 mile limit.
The issue was raised in the UN in 1967 by Arvid Pardo and in 1973 the Third United Nations Conference on the Law of the Sea was convened in New York to write a new treaty covering the oceans. The conference lasted until 1982 and over 160 nations participated. The convention came into force on November 14, 1994, one year after the sixtieth state, Guyana, signed it.
The convention introduced a number of provisions, the most significant issues covered were - setting limits; navigation; exclusive economic zones (EEZ); 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 territorial waters to 12 miles, in which area the controlling state is free to set laws, regulate any use and use any resource. Vessels were given the right of 'innocent passage' through any territorial waters, with strategic straits allowing the passage of military craft as 'transit passage', in that naval vessels are allowed to maintain postures that would be illegal in territorial waters. Beyond the 12 mile limit there was a further 24 mile limit, the 'contiguous zone', in which area a state could continue to enforce laws regarding activities such a smuggling or illegal immigration.
The exclusive economic zones (EEZ) extended the exploitation rights of coastal nations to 200 miles from shore, covering all natural resources. The EEZ were introduced to halt the increasingly heated clashes over fishing rights, although oil was also becoming important. The success of an offshore oil platform in the Gulf of Mexico in 1947 was soon repeated elsewhere in the world, by 1970 it was technically feasible to operate in waters 4000 metres deep.
Aside from its provisions defining ocean boundaries, the convention establishes general obligations for safeguarding the marine environment and protecting freedom of scientific research on the high seas, and also creates an innovative legal regime for controlling mineral resource exploitation in deep seabed areas beyond national jurisdiction, through an International Seabed Authority.
Opened for signature - December 10, 1982
Parties - (137) Algeria, Angola, Antigua and Barbuda, Argentina, Australia, Austria, The Bahamas, Bahrain, Bangladesh, Barbados, Belgium, Belize, Benin, Bolivia, Bosnia and Herzegovina, Botswana, Brazil, Brunei, Bulgaria, Burma, Cameroon, Cape Verde, Chile, China, Comoros, Democratic Republic of the Congo, Cook Islands, Costa Rica, Côte d'Ivoire, Croatia, Cuba, Cyprus, Czech Republic, Djibouti, Dominica, Egypt, Equatorial Guinea, European Union, Fiji, Finland, France, Gabon, The Gambia, Georgia, Germany, Ghana, Greece, Grenada, Guatemala, Guinea, Guinea-Bissau, Guyana, Haiti, Honduras, Iceland, India, Indonesia, Iraq, Ireland, Italy, Jamaica, Japan, Jordan, Kenya, South Korea, Kuwait, Laos, Lebanon, Luxembourg, The Former Yugoslav Republic of Macedonia, Madagascar, Malaysia, Maldives, Mali, Malta, Marshall Islands, Mauritania, Mauritius, Mexico, Federated States of Micronesia, Monaco, Mongolia, Mozambique, Namibia, Nauru, Nepal, Netherlands, New Zealand, Nicaragua, Nigeria, Norway, Oman, Pakistan, Palau, Panama, Papua New Guinea, Paraguay, Philippines, Poland, Portugal, Romania, Russia, Saint Kitts and Nevis, Saint Lucia, Saint Vincent and the Grenadines, Samoa, Sao Tome and Principe, Saudi Arabia, Senegal, Serbia and Montenegro, Seychelles, Sierra Leone, Singapore, Slovakia, Slovenia, Solomon Islands, Somalia, South Africa, Spain, Sri Lanka, Sudan, Suriname, Sweden, Tanzania, Togo, Tonga, Trinidad and Tobago, Tunisia, Uganda, Ukraine, United Kingdom, Uruguay, Vanuatu, Vietnam, Yemen, Zambia, Zimbabwe
Countries that have signed, but not yet ratified - (33) Afghanistan, Belarus, Bhutan, Burkina Faso, Burundi, Cambodia, Canada, Central African Republic, Chad, Colombia, Republic of the Congo, Denmark, Dominican Republic, El Salvador, Ethiopia, Hungary, Iran, North Korea, Lesotho, Liberia, Libya, Liechtenstein, Malawi, Morocco, Niger, Niue, Qatar, Rwanda, Swaziland, Switzerland, Thailand, Tuvalu, United Arab Emirates