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 the international agreement that resulted from the third United Nations Conference on the Law of the Sea (UNCLOS III), which took place from 1973 through 1982. The Law of the Sea Convention defines the rights and responsibilities of nations in their use of the world's oceans, establishing guidelines for businesses, the environment, and the management of marine natural resources. The Convention, concluded in 1982, replaced four 1958 treaties. UNCLOS came into force in 1994, a year after Guyana became the 60th state to sign the treaty. To date, 162 countries and the European Community have joined in the Convention. However, it is uncertain as to what extent the Convention codifies customary international law.

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:

Internal waters

Covers all water and waterways on the landward side of the baseline. The coastal state is free to set laws, regulate use, and use any resource. Foreign vessels have no right of passage within internal waters.

Territorial waters

Out to 12 nautical miles (22 kilometres; 14 miles) from the baseline, the coastal state is free to set laws, regulate 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. "Innocent passage" is defined by the convention as passing through waters in an expeditious and continuous manner, which is not "prejudicial to the peace, good order or the security" of the coastal state. Fishing, polluting, weapons practice, and spying are not "innocent", and submarines and other underwater vehicles are required to navigate on the surface and to show their flag. Nations can also temporarily suspend innocent passage in specific areas of their territorial seas, if doing so is essential for the protection of its security.

Archipelagic waters

The convention set the definition of Archipelagic States in Part IV, which also defines how the state can draw its territorial borders. A baseline is drawn between the outermost points of the outermost islands, subject to these points being sufficiently close to one another. All waters inside this baseline are designated Archipelagic Waters. The state has full sovereignty over these waters (like internal waters), but foreign vessels have right of innocent passage through archipelagic waters (like territorial waters).

Contiguous zone

Beyond the 12 nautical mile limit, there is a further 12 nautical miles from the territorial sea baseline limit, the contiguous zone, in which a state can continue to enforce laws in four specific areas: customs, taxation, immigration and pollution, if the infringement started within the state's territory or territorial waters, or if this infringement is about to occur within the state's territory or territorial waters.^[4] This makes the contiguous zone a hot pursuit area.

Exclusive economic zones (EEZs)

These extend from the edge of the territorial sea out to 200 nautical miles (370 kilometres; 230 miles) from the baseline. Within this area, the coastal nation has sole exploitation rights over all natural resources. In casual use, the term may include the territorial sea and even the continental shelf. The EEZs 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, and by 1970 it was technically feasible to operate in waters 4000 metres deep. Foreign nations have the freedom of navigation and overflight, subject to the regulation of the coastal states. Foreign states may also lay submarine pipes and cables.

Continental shelf

The continental shelf is defined as the natural prolongation of the land territory to the continental margin’s outer edge, or 200 nautical miles from the coastal state’s baseline, whichever is greater. A state’s continental shelf may exceed 200 nautical miles until the natural prolongation ends. However, it may never exceed 350 nautical miles (650 kilometres; 400 miles) from the baseline; or it may never exceed 100 nautical miles (190 kilometres; 120 miles) beyond the 2,500 meter isobath (the line connecting the depth of 2,500 meters). Coastal states have the right to harvest mineral and non-living material in the subsoil of its continental shelf, to the exclusion of others. Coastal states also have exclusive control over living resources "attached" to the continental shelf, but not to creatures living in the water column beyond the exclusive economic zone.

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 and the Common heritage of mankind principle.^[5]

Landlocked states are given a right of access to and from the sea, without taxation of traffic through transit states.

[edit]Part XI and the 1994 Agreement

Part XI of the Convention provides for a regime relating to minerals on the seabed outside any state's territorial waters or EEZ (Exclusive Economic Zones). It establishes an International Seabed Authority (ISA) to authorize seabed exploration and mining and collect and distribute the seabed mining royalty.

The United States objected to the provisions of Part XI of the Convention on several grounds, arguing that the treaty was unfavorable to American economic and security interests. Due to Part XI, the United States refused to ratify the UNCLOS, although it expressed agreement with the remaining provisions of the Convention.

From 1983 to 1990, the United States accepted all but Part XI as customary international law, while attempting to establish an alternative regime for exploitation of the minerals of the deep seabed. An agreement was made with other seabed mining nations and licenses were granted to four international consortia. Concurrently, the Preparatory Commission was established to prepare for the eventual coming into force of the Convention-recognized claims by applicants, sponsored by signatories of the Convention. Overlaps between the two groups were resolved, but a decline in the demand for minerals from the seabed made the seabed regime significantly less relevant. In addition, the decline of Socialism and the fall of Communism in the late 1980s had removed much of the support for some of the more contentious Part XI provisions.

In 1990, consultations were begun between signatories and non-signatories (including the United States) over the possibility of modifying the Convention to allow the industrialized countries to join the Convention. The resulting 1994 Agreement on Implementation was adopted as a binding international Convention. It mandated that key articles, including those on limitation of seabed production and mandatory technology transfer, would not be applied, that the United States, if it became a member, would be guaranteed a seat on the Council of the International Seabed Authority, and finally, that voting would be done in groups, with each group able to block decisions on substantive matters. The 1994 Agreement also established a Finance Committee that would originate the financial decisions of the Authority, to which the largest donors would automatically be members and in which decisions would be made by consensus.

On February 1, 2011, the Seabed Disputes Chamber of the International Tribunal for the Law of the Sea (ITLOS) issued an advisory opinion concerning the legal responsibilities and obligations of States Parties to the Convention with respect to the sponsorship of activities in the Area in accordance with Part XI of the Convention and the 1994 Agreement.^[6] The advisory opinion was issued in response to a formal request made by the International Seabed Authority following two prior applications the Authority's Legal and Technical Commission had received from the Republics of Nauru and Tonga regarding proposed activities (a plan of work to explore for polymetallic nodules) to be undertaken in the Area by two State-sponsored contractors (Nauru Ocean Resources Inc. (sponsored by the Republic of Nauru) and Tonga Offshore Mining Ltd. (sponsored by the Kingdom of Tonga). The advisory opinion set forth the international legal responsibilities and obligations of Sponsoring States AND the Authority to ensure that sponsored activities do not harm the marine environment, consistent with the applicable provisions of UNCLOS Part XI, Authority regulations, ITLOS case law, other international environmental treaties, and Principle 15 of the UN Rio Declaration