Maarg Manthan · Topic 12.6

UNCLOS, Territorial Waters and Exclusive Economic Zone

Geography › Coral Reefs, Ocean Resources and Law of the Sea · Topic 12.6

The United Nations Convention on the Law of the Sea, UNCLOS, adopted in 1982 and in force since 1994, divides the sea into zones measured from the baseline: internal waters, territorial sea of 12 nautical miles, contiguous zone of 24, exclusive economic zone of 200, the continental shelf, the high seas and the international seabed Area. Each zone gives a coastal state different rights, from full sovereignty to resource rights only.

7 min read · UPSC Prelims · Geography · Coral Reefs, Ocean Resources and Law of the Sea

At a Glance

Territorial sea Up to 12 nautical miles; sovereignty
Contiguous zone Up to 24 nautical miles; enforcement
EEZ Up to 200 nautical miles; resource rights
Adopted / in force 1982 / 1994
India Ratified 1995; EEZ about 2 million sq km
Exam link UPSC Prelims, Geography: Coral Reefs, Ocean Resources and Law of the Sea

Where Does It Fit?

This is the last topic of the macro on the oceans’ resources and the law of the sea. The previous topics described the living and non-living resources, and this one explains the legal framework that decides who can use them. The next macro begins the study of India, starting with its location and geology. Previous topic: Energy and Biotic Resources of the Oceans. Next topic: India as a Geographical Unit and Its Frontiers.

What Is UNCLOS and Why Was It Needed?

In short: UNCLOS is the constitution of the oceans, setting out which state can do what, how far from its coast.

For centuries, the sea was governed by custom, in which states claimed a narrow belt of coastal water, the range of a cannon, and the rest was free. After the Second World War, states claimed larger areas for oil, fish and security, and competing claims grew. The United Nations held three conferences, and the Convention was adopted in 1982 at Montego Bay, Jamaica. It entered into force on 16 November 1994, after 60 ratifications, and has now been joined by over 165 states and the European Union. India ratified it in 1995. The United States follows most of its rules as customary law, but has not ratified it. The Convention created three bodies: the International Tribunal for the Law of the Sea, ITLOS, in Hamburg, the International Seabed Authority in Kingston, as in copper, cobalt Regulator International Seabed Authority,…">Ocean Deposits and Mineral Resources, and the Commission on the Limits of the Continental Shelf.

What Are the Maritime Zones?

Zone	Limit from the baseline	Rights of the coastal state
Internal waters	Landward of the baseline: bays, ports, rivers	Full sovereignty; no right of innocent passage
Territorial sea	Up to 12 nautical miles	Sovereignty over water, seabed and airspace; foreign ships have the right of innocent passage, which is the right to pass quickly and peacefully, without harming the coastal state’s peace and security; submarines must surface and show their flag
Contiguous zone	Up to 24 nautical miles	Power to prevent and punish violations of customs, fiscal, immigration and sanitary laws; not sovereignty
Exclusive economic zone (EEZ)	Up to 200 nautical miles	Sovereign rights to explore, use, conserve and manage the living and non-living resources, and jurisdiction over artificial islands, marine research and the environment; other states keep freedom of navigation, overflight and laying cables
Continental shelf	Natural prolongation of the land, at least 200 nautical miles, and in some cases up to 350 nautical miles or 100 nautical miles beyond the 2,500 m depth line	Sovereign rights over the seabed and subsoil resources such as oil and minerals; claims beyond 200 miles are submitted to the Commission
High seas	Beyond the EEZ	Open to all states: freedom of navigation, fishing, overflight and research; no state can claim sovereignty
The Area	The seabed beyond national jurisdiction	Common heritage of mankind, managed by the International Seabed Authority

The baseline is usually the low-water line along the coast, and straight baselines may be drawn across deeply indented coasts. One nautical mile is 1.852 km, so 12 nautical miles is about 22 km and 200 is about 370 km. Archipelagic states, such as Indonesia and the Philippines, can draw baselines around the outermost islands. Straits used for international navigation allow transit passage, which is stronger than innocent passage. Rocks that cannot support human habitation or economic life have no EEZ, as in Article 121, a rule that is central to disputes over small islets. The Convention also provides for hot pursuit of a ship that breaks the law, and for compulsory dispute settlement through ITLOS, the International Court of Justice or arbitration. The straits and chokepoints that these rules cover are discussed in Bays, Gulfs, Straits and Isthmuses.

How Does UNCLOS Apply to India?

Domestic law: the Territorial Waters, Continental Shelf, Exclusive Economic Zone and Other Maritime Zones Act, 1976, set India’s 12 nautical mile territorial sea, 24 nautical mile contiguous zone and 200 nautical mile EEZ. India’s EEZ is about 2 million square kilometres, one of the largest in the world, and the Andaman and Nicobar and Lakshadweep islands contribute a large share of it.
Extended shelf: India submitted a claim to the Commission on the Limits of the Continental Shelf in 2009 for the seabed beyond 200 nautical miles in the Bay of Bengal and the Arabian Sea.
Boundaries and disputes: India has settled maritime boundaries with Sri Lanka, the Maldives, Indonesia, Thailand, Myanmar and others. In 2014, the arbitral tribunal under UNCLOS settled the maritime boundary dispute with Bangladesh in the Bay of Bengal, awarding most of the disputed area to Bangladesh, and India accepted the verdict. In the Enrica Lexie case, an arbitral tribunal in 2020 held that the Italian marines were entitled to immunity, so Italy and not India could prosecute them, while India was entitled to compensation for the loss of life and damage.
South China Sea: the 2016 arbitral award, which rejected the legal basis of historic rights over most of the sea, has been supported by India, which has urged all parties to respect the ruling and to follow UNCLOS, as in Marginal Seas.

As an analytical point, the Convention transformed the oceans: more than a third of the sea became national jurisdiction in the form of EEZs, and with it the responsibility to manage fish, minerals and pollution. The next frontier is the area beyond national jurisdiction, where the deep seabed, as in Ocean Deposits and Mineral Resources, and high seas biodiversity, under the BBNJ Agreement which was due to come into force in January 2026, will test how far the principle of common heritage can be put into practice.

Why Is This Topic Important?

Facts Distances and rights asked every year
Disputes South China Sea and Bangladesh
India EEZ and blue economy

What Came Next?

The next macro begins the study of India, starting with its location, size and frontiers. Next topic: India as a Geographical Unit and Its Frontiers.

Key People and Terms

Baseline Line from which zones are measured
Innocent passage Peaceful passage through territorial sea
EEZ Exclusive economic zone
Contiguous zone Enforcement belt beyond territorial sea
Nautical mile 1.852 kilometres
ITLOS International Tribunal for the Law of the Sea

Exam Corner

Points to Remember

Territorial sea 12, contiguous zone 24, EEZ 200 nautical miles.
UNCLOS was adopted in 1982, in force 1994.
Innocent passage applies in the territorial sea.
The EEZ gives resource rights, not sovereignty.
India ratified UNCLOS in 1995.

Do Not Confuse With

Territorial sea and EEZ Sovereignty versus sovereign rights
Innocent passage and transit passage Territorial sea versus international straits
High seas and the Area Water column versus seabed

Memory Hook

Twelve is ours, twenty-four we police, two hundred we harvest; beyond that, the sea is everyone’s.

Mains Angle

Questions ask for zones, rights and India’s disputes. These points add depth.

Zones Graded rights
India EEZ and boundary awards
Frontier Seabed and high seas

A Question You May Face

An original practice question, not a past paper question.

“Explain the maritime zones under UNCLOS and discuss their significance for India’s blue economy and maritime security.”

How to Answer

Zones 12, 24, 200 miles.
Rights Sovereignty versus resource rights.
India EEZ, Bangladesh award.
Future Seabed and BBNJ.

GS Relevance

Prelims: zones with distances and rights, innocent passage, ITLOS, India's EEZ. GS Paper 2: international law and maritime disputes; GS Paper 3: blue economy.

Frequently Asked Questions

What is UNCLOS?

The United Nations Convention on the Law of the Sea is an international treaty adopted in 1982, which came into force in 1994. It sets out the rights and duties of states in the oceans, defining zones such as territorial sea, contiguous zone, exclusive economic zone and continental shelf, and sets up bodies to manage the seabed and settle disputes.

What are territorial waters?

Territorial waters, or the territorial sea, extend up to 12 nautical miles from the baseline of a coastal state. The state has sovereignty over the water, seabed and airspace, but foreign ships have the right of innocent passage, which means passing through peacefully and quickly.

What is the exclusive economic zone?

The exclusive economic zone extends up to 200 nautical miles from the baseline. The coastal state has sovereign rights to explore, use and manage the fish, oil, gas and other resources in the water and on the seabed, while other countries retain freedom of navigation, overflight and cable laying.

What is the difference between the territorial sea and the EEZ?

In the territorial sea, up to 12 nautical miles, a state has full sovereignty, including airspace, subject only to innocent passage. In the EEZ, up to 200 nautical miles, a state has only sovereign rights over resources and certain jurisdiction, and ships and aircraft of all countries can move freely.

What is the size of India's EEZ?

India's exclusive economic zone is about 2 million square kilometres, among the largest in the world, which includes the waters around the mainland and the Andaman and Nicobar and Lakshadweep islands. It was set up by the 1976 Maritime Zones Act and is recognised under UNCLOS, which India ratified in 1995.

PYQ Practice — Statement Analysis

1 The territorial sea extends up to 12 nautical miles from the baseline.

True

The coastal state has sovereignty there.

2 In the EEZ, a coastal state has full sovereignty as in its territorial sea.

False

It has sovereign rights over resources only.

3 The contiguous zone extends up to 24 nautical miles.