Maritime Zones, Exclusive Economic Zone and UNCLOS Provisions

The United Nations Convention on the Law of the Sea (UNCLOS), adopted in 1982 and in force since 1994, establishes the legal framework for all ocean spaces. It defines distinct maritime zones measured from officially recognized baselines: internal waters, the territorial sea, the contiguous zone, the exclusive economic zone (EEZ), the continental shelf, and the high seas.

Baselines and Internal Waters

Baselines serve as the starting line for measuring the breadth of all maritime zones. Coastal states apply two main methods to determine these lines.

Normal and Straight Baselines

• Normal Baseline: Drawn along the low-water line of the coast, as marked on large-scale charts officially recognized by the coastal state.
• Straight Baseline: Applied in areas where the coastline is deeply indented or cut into, or where there is a fringe of islands along the coast in its immediate vicinity.
• Archipelagic Baseline: Special straight baselines drawn by archipelagic states (like Indonesia and the Philippines) joining the outermost points of the outermost islands.

Internal Waters

• Internal waters encompass all waters landward of the baseline, including bays, ports, rivers, estuaries, and landlocked coastal lakes.
• The coastal state exercises complete sovereignty over internal waters, identical to its land territory.
• Foreign vessels have no automatic right of innocent passage through internal waters, except where a straight baseline encloses waters not previously considered internal.

Territorial Sea and Contiguous Zone

Territorial Sea

• Extends seaward up to 12 nautical miles (1 NM = 1.852 km) from the baseline.
• The coastal state exercises full sovereignty over the water column, the seabed, subsoil, and the superjacent airspace.
• Right of Innocent Passage: Foreign civilian and commercial ships enjoy the right of innocent passage through the territorial sea.
• Passage is innocent so long as it is not prejudicial to the peace, good order, or security of the coastal state.
• Submarines and underwater vehicles navigating the territorial sea must travel on the surface and show their flag.

Contiguous Zone

• Extends seaward up to 24 nautical miles from the baseline (an additional 12 nautical miles beyond the territorial sea).
• Coastal states do not possess complete sovereignty here, but exercise specific preventive and punitive jurisdiction.
• The coastal state can enforce laws to prevent and punish infringements of its customs, fiscal, immigration, and sanitary (sanitation) laws committed within its territory or territorial sea.

Exclusive Economic Zone (EEZ) and Continental Shelf

Exclusive Economic Zone (EEZ)

• Extends seaward up to 200 nautical miles from the baseline (or 188 nautical miles from the outer limit of the territorial sea).
• Sovereign Rights: The coastal state holds exclusive sovereign rights to explore, exploit, conserve, and manage natural resources, both living (fisheries) and non-living (oil, gas, minerals) in the waters superjacent to the seabed, the seabed, and its subsoil.
• Economic Production: The coastal state has sovereign rights for activities like producing energy from water, currents, and winds.
• Jurisdiction: The coastal state has jurisdiction over the establishment and use of artificial islands, offshore installations, marine scientific research, and marine environmental protection.
• Freedoms for Other States: All foreign states enjoy the freedom of navigation, overflight, and the laying of submarine cables and pipelines in the EEZ.

Continental Shelf

• Comprises the seabed and subsoil of submarine areas that extend beyond the territorial sea throughout the natural prolongation of its land territory to the outer edge of the continental margin.
• Set at a minimum of 200 nautical miles from the baseline, even if the physical shelf is narrower.
• If the geological continental margin extends beyond 200 nautical miles, a state can claim an Extended Continental Shelf up to 350 nautical miles from the baseline (or up to 100 nautical miles from the 2,500-meter isobath).
• Extended shelf claims must be submitted to and approved by the Commission on the Limits of the Continental Shelf (CLCS).
• The coastal state exercises exclusive sovereign rights over sedentary living species and non-living mineral resources of the seabed and subsoil.

High Seas and the International Seabed Area

The High Seas

• Covers all parts of the sea that are not included in the EEZ, territorial sea, internal waters, or archipelagic waters of any state.
• Open to all states, coastal or landlocked.
• Freedoms include navigation, overflight, scientific research, construction of artificial installations, and fishing (subject to conservation obligations).
• Reserved exclusively for peaceful purposes.
• Flag-state jurisdiction applies: ships on the high seas are generally subject to the exclusive authority of the country whose flag they fly.

The Area and Common Heritage of Mankind

• “The Area” refers to the seabed, ocean floor, and subsoil beyond the limits of national jurisdiction.
• Declared as the Common Heritage of Mankind under Part XI of UNCLOS.
• No state or entity can claim sovereignty or sovereign rights over any part of the Area or its resources.
• Exploration and commercial extraction of polymetallic nodules and seafloor massive sulphides are organized and controlled by the International Seabed Authority (ISA), based in Kingston, Jamaica.

Institutional Framework Under UNCLOS

UNCLOS established three dedicated international institutions to administer ocean governance, boundary claims, and disputes.

Key International Bodies

• International Tribunal for the Law of the Sea (ITLOS): An independent judicial body established in Hamburg, Germany, to adjudicate disputes arising out of the interpretation and application of the Convention.
• International Seabed Authority (ISA): An autonomous organization based in Kingston, Jamaica, through which state parties organize and control all mineral-related activities in the Area.
• Commission on the Limits of the Continental Shelf (CLCS): A scientific body based at the UN Headquarters in New York that examines data submitted by coastal states claiming an outer continental shelf beyond 200 nautical miles.

Indian Legal and Strategic Framework

India enacted domestic legislation and ratified global treaties to govern its maritime boundaries and harness oceanic resources.

Domestic Legislation and Constitutional Status

• Article 297 of the Constitution of India vests all lands, minerals, and other things of value underlying the ocean within territorial waters, continental shelf, and EEZ in the Union of India.
• The Territorial Waters, Continental Shelf, Exclusive Economic Zone and Other Maritime Zones Act, 1976 gives domestic statutory effect to the maritime zones of India.
• The Maritime Zones of India (Regulation of Fishing by Foreign Vessels) Act, 1981 regulates commercial foreign fishing fleets within India’s EEZ.
• The Admiralty (Jurisdiction and Settlement of Maritime Claims) Act, 2017 vests admiralty jurisdiction in coastal High Courts over maritime claims.

India’s Maritime Extent

• India has a coastline of 7,516.6 km (mainland: 5,422.6 km; island territories: 2,094 km).
• India’s EEZ covers an area of approximately 2.37 million square kilometers.
• India was granted Pioneer Investor status in 1987 by the ISA and allocated an exploration site of 75,000 square kilometers in the Central Indian Ocean Basin for polymetallic nodule mining.
• India has submitted claims to the CLCS to extend its continental shelf in the Arabian Sea and the Bay of Bengal beyond 200 nautical miles.

Key Facts

• UNCLOS was adopted on December 10, 1982, at Montego Bay, Jamaica, and entered into force on November 16, 1994.
• UNCLOS replaced four 1958 Geneva Conventions covering the Territorial Sea, Continental Shelf, High Seas, and Fishing.
• One nautical mile equals 1,852 meters (1.852 km), derived from one minute of latitude along the Earth’s meridian.
• The International Seabed Authority (ISA) was established under the 1982 UNCLOS and its 1994 Agreement on Implementation.
• The BBNJ Agreement (Biodiversity Beyond National Jurisdiction), also known as the High Seas Treaty, was formally adopted in 2023 under UNCLOS to protect marine biological diversity in areas beyond national jurisdiction.
• Landlocked states retain the right of access to and from the sea and enjoy freedom of transit through the territory of transit states under Part X of UNCLOS.
• The Right of Hot Pursuit allows a coastal state’s warship or military aircraft to pursue a foreign ship that violates its domestic laws into the high seas if the pursuit began in its internal waters, territorial sea, or contiguous zone.
• Artificial islands, installations, and structures in the EEZ do not possess the legal status of islands; they have no territorial sea of their own and their presence does not alter maritime boundary delimitation.
• Sedentary species are defined under UNCLOS as organisms which, at the harvestable stage, either are immobile on or under the seabed or are unable to move except in constant physical contact with the seabed or subsoil.