Maritime Zones Under the UNCLOS

 

The United Nations Convention for the Law of the Sea (UNCLOS) is a treaty that defines the law of the sea. It became effective from 16 November 1982. The full text of the UNCLOS is available at the United Nations website (or click here for a PDF copy).

Under Article 5 of the UNCLOS, the reference point for the maritime zones is the low-water mark where dry land ends at low tide. This is called the baseline.

Article 5 — Normal baseline. Except where otherwise provided in this Convention, the normal baseline for measuring the breadth of the territorial sea is the low-water line along the coast as marked on large-scale charts officially recognised by the coastal State. 

THE TERRITORIAL SEA

Under Article 3 of the UNCLOS, the coastal state can have up to 12 nautical miles of territorial sea reckoned from the baseline. In other words, 12 nautical miles from the shore is territorial sea.

Article 3 — Breadth of the territorial sea. Every State has the right to establish the breadth of its territorial sea up to a limit not exceeding 12 nautical miles, measured from baselines determined in accordance with this Convention.

Under Article 2 of the UNCLOS, the coastal state has sovereignty over the territorial sea, its sea bed and subsoil, as well as the air space above it.

THE CONTIGUOUS ZONE

Under Article 33 of the UNCLOS, the coastal state has control of the zone contiguous to its territorial sea, called the contiguous zone. The contiguous zone is measured from the baseline and can extend up to 24 nautical miles. Because the territorial sea consists of the first 12 nautical miles, the contiguous zone is therefore only 12 nautical miles from where the territorial sea ends.

Article 33 — Contiguous zone. (2) The contiguous zone may not extend beyond 24 nautical miles from the baselines from which the breadth of the territorial sea is measured.

Under the first paragraph of Article 33 of the UNCLOS, the coastal state will exercise control over the contiguous zone as may be necessary to prevent infringement of its customs, fiscal, immigration or sanitary laws and regulations within its territory or territorial sea OR to punish infringement of the above laws and regulations committed within its territory or territorial sea.

THE EXCLUSIVE ECONOMIC ZONE

Under Article 57 of the UNCLOS, the coastal state can have up to 200 nautical miles of exclusive economic zone (EEZ). The EEZ is measured from the baseline. Because the first 24 nautical miles from the baseline consists of the territorial sea and the contiguous zone, the EEZ will extend 176 nautical miles from where the contiguous zone ends.

Article 57 — Breadth of the exclusive economic zone. The exclusive economic zone shall not extend beyond 200 nautical miles from the baselines from which the breadth of the territorial sea is measured.

Under Article 56 of the UNCLOS, the coastal state will have sovereign rights over its EEZ for the purpose of exploring and exploiting, conserving and managing the natural resources, whether living or non-living, of the waters superjacent to the seabed and of the seabed and its subsoil, and with regard to other activities for the economic exploitation and exploration of the zone, such as the production of energy from the water, currents and winds. In addition, the state will also have jurisdiction in the EEZ for the establishment and use artificial islands, installations and structures; marine scientific research; and the protection and preservation of the marine environment, among others.

It is very important, however, to emphasise that under the UNCLOS, other states are free to pass through another state's EEZ. This is called the freedom of navigation and overflight under Article 87, which also includes laying of submarine cables and pipelines.