Maritime zones of India

Topic: India: Location, Size, Extent and Divisions · NCERT: Beyond NCERT

Meaning

Maritime zones of India are the belts of sea and seabed, all measured outwards from India's baseline, where India has rights. Under the Maritime Zones Act 1976 and UNCLOS there are four of them: the territorial sea (12 nm), the contiguous zone (24 nm), the exclusive economic zone or EEZ (200 nm) and the continental shelf (200 nm, or up to 350 nm where the continental margin goes further).

India's rights get weaker as you move out from the coast. India has full sovereignty near the coast, but only resource rights further out. These zones give India a sea area of more than 2.2 million sq km [1]. That area holds fish, oil, gas and minerals, and it has to be guarded for security.

Explanation

Measuring the zones: baseline and nautical mile

• Baseline: the official coastline from which every zone is measured.
• Normally it is the low-water line (the line the sea reaches at low tide).

• Each zone limit is a line on which every point is the stated distance from the nearest point of the baseline [5].

• Nautical mile (nm): the mile used at sea by ships and aircraft.

• 1 nm = 1.852 km = 72,960 inches.
• 1 nm = one minute of latitude (a minute is 1/60 of a degree). So 60 nm = 1° of latitude, and a navigator can read distance straight off a chart.

• The ordinary land mile (statute mile) is shorter: about 1.6 km (63,360 inches).

• Quick conversions: 12 nm ≈ 22.2 km (NCERT: about 21.9 km) · 24 nm ≈ 44.4 km · 200 nm ≈ 370.4 km · 350 nm ≈ 648 km.

The legal framework

• Maritime Zones Act 1976: full name The Territorial Waters, Continental Shelf, Exclusive Economic Zone and Other Maritime Zones Act, 1976. It is Act No. 80 of 1976. It was enacted on 25 August 1976 and came into force on 15 January 1977 [5].

• India passed this law before UNCLOS existed, but it already used the same limits of 12, 24 and 200 nm [5].

• UNCLOS (United Nations Convention on the Law of the Sea): the world treaty that sets the rules for using the oceans.

• Adopted in 1982 at Montego Bay (Jamaica). It came into force in 1994, and India ratified it in 1995.
• Part II covers the territorial sea and contiguous zone. Part V covers the EEZ. Part VI covers the continental shelf.

The four zones, from the coast outwards

Zone	Outer limit	Approx. km	India's rights
Territorial sea	12 nm	22.2	Full sovereignty, subject to innocent passage
Contiguous zone	24 nm	44.4	Policing for customs, fiscal, immigration, sanitary and security purposes
EEZ	200 nm	370.4	Sovereign rights over resources only
Continental shelf	200 nm, or the margin's edge up to 350 nm	370–648	Rights over the seabed and subsoil only

• Territorial sea (0–12 nm):
• India treats this belt like its own land. It controls the water, seabed, subsoil and the airspace above.

• Innocent passage means foreign ships may pass through without stopping, as long as they do not harm India's peace, good order or security.

  • A cargo ship sailing quietly past the Gujarat coast is in innocent passage. A ship that fishes, spies or pollutes is not.
  • This right covers ships only. Foreign aircraft need permission to fly over.

• Contiguous zone (12–24 nm) [5]:

• India has policing powers only, not sovereignty:
  • customs, to stop smuggling of goods;
  • fiscal, to collect taxes and duties;
  • immigration, to stop illegal entry of people;
  • sanitary, to protect health, for example by quarantine;
  • security, to protect the country.

• Why it exists: India can catch a smuggler before the smuggler crosses the 12 nm line.

• Exclusive economic zone (up to 200 nm) [5]:

• India has sovereign rights: only India may explore, use, conserve and manage the resources.
  • Living resources: fish, prawns and other marine life.
  • Non-living resources: oil, natural gas and minerals.
  • Other economic uses: energy from wind, waves and currents.

• Other states keep freedom of navigation and overflight, and may lay submarine cables and pipelines.

• Continental shelf (legal meaning):

• It is the seabed and subsoil beyond the territorial sea. It is the natural prolongation (the underwater continuation) of India's land. It reaches either the outer edge of the continental margin (where the continent's rock ends and the deep ocean floor begins), or 200 nm if the margin ends before that [5].
• Extended continental shelf: if the margin goes beyond 200 nm, a state can claim seabed rights up to 350 nm.
  • First, it must send scientific proof to the CLCS (Commission on the Limits of the Continental Shelf: the UN expert body that checks such claims).
• The water above the shelf beyond 200 nm is still the high seas.

Beyond national limits

• High seas: all the water beyond every country's EEZ. It is open to all states, and no country owns it.
• International Seabed Area ("the Area"): the seabed beyond every country's continental shelf.
• UNCLOS calls its minerals the "common heritage of mankind".
• It is managed by the International Seabed Authority (ISA), based in Kingston, Jamaica.

Where it occurs

• Coasts: the zones run along India's whole west coast (Arabian Sea) and east coast (Bay of Bengal).
• Island territories:
• The Andaman and Nicobar Islands (Bay of Bengal) and Lakshadweep (Arabian Sea) add a large share of the EEZ.
• Each island creates its own 200 nm circle, so a long island chain gives a very large sea area.

• The Andaman and Nicobar Islands also sit close to the Malacca Strait shipping route.

• Size of the EEZ: more than 2.2 million sq km [1]. That is roughly two-thirds of India's land area (about 3.28 million sq km).

• Other sources give about 2.02 or 2.37 million sq km, because they calculate it in different ways.

• Mumbai High: offshore oil and gas in the Arabian Sea, off the Maharashtra coast. It lies in the continental shelf / EEZ.

• Extended shelf claim:
• India filed a partial submission with the CLCS on 11 May 2009. It kept the right to file a separate claim later for the southern Bay of Bengal [6].
• On 3 April 2025, India filed an amended partial submission for the Western Offshore Region, covering the Central Arabian Sea and the Northern Arabian Sea [6][7].
• The CLCS put the amended submission on the agenda of its 64th session (New York, 7 July – 8 August 2025) [7].

• Myanmar, Bangladesh, Oman and Pakistan have sent notes to the UN about India's submissions [6].

• Central Indian Ocean Basin (CIOB): this lies in the International Seabed Area, beyond India's own zones.

• India holds rights here, under an ISA contract, to explore polymetallic nodules (potato-sized lumps on the deep ocean floor that contain many metals).

• Area: 75,000 sq km. First estimates: about 380 million metric tonnes of nodules, holding copper, nickel, cobalt and manganese [1].

• Deep Ocean Mission: approved in 2021 and run by the Ministry of Earth Sciences, with ₹4,077 crore for 2021–2026 [3].

• It is building a manned submersible (a small deep-diving craft) to take three people to 6,000 m depth.

• It is also building a mining system to collect nodules from 6,000 m in the Central Indian Ocean [1][2].

• India–Bangladesh (Bay of Bengal): a tribunal set up under Annex VII of UNCLOS gave its award on 7 July 2014. The Permanent Court of Arbitration (The Hague) acted as the registry. The award is final and binding [4].

• Palk Bay: fishermen from India and Sri Lanka cross the sea border here.

Don't confuse with

• Territorial sea vs EEZ: in the territorial sea India has full sovereignty, including the airspace. In the EEZ it has only sovereign rights over resources, and other states can still sail, fly over and lay cables there. Sovereignty ends at 12 nm.
• Contiguous zone vs territorial sea: the contiguous zone (12–24 nm) gives only policing powers (customs, fiscal, immigration, sanitary, security). It gives no sovereignty and no resource rights.
• Legal continental shelf vs EEZ: shelf rights cover only the seabed and subsoil, and can reach 350 nm. The EEZ covers the water and seabed but stops at 200 nm. (The continental shelf as a physical landform is a separate idea.)
• Nautical mile vs statute mile: a nautical mile is 1.852 km (one minute of latitude). A statute mile is about 1.6 km and is used on land.

Prelims Hooks

• Order from the baseline outwards: territorial sea (12 nm) → contiguous zone (24 nm) → EEZ (200 nm) → extended continental shelf (up to 350 nm) → high seas / International Seabed Area.
• Only the territorial sea gives full sovereignty, including the airspace. Innocent passage is for ships only, not aircraft.
• India's Act came before UNCLOS: Act No. 80 of 1976, in force from 15 January 1977 [5]. UNCLOS was adopted in 1982 (Montego Bay), came into force in 1994, and India ratified it in 1995.
• Trap: in India's EEZ, other states keep freedom of navigation, overflight and laying cables and pipelines. Only resource rights belong to India.
• Extended shelf claim: filed with the CLCS on 11 May 2009, then amended on 3 April 2025 for the Arabian Sea [6].
• India–Bangladesh sea boundary: settled by a UNCLOS Annex VII tribunal award on 7 July 2014, with the PCA as registry [4].

Mains Points

• The EEZ is a resource base (GS-III):
• At more than 2.2 million sq km, the EEZ supports fisheries and coastal jobs, and offshore oil at Mumbai High [1].
• Copper, nickel and cobalt from the CIOB nodules are needed for batteries and the move to clean energy.
• The Deep Ocean Mission is how India is trying to reach these resources [1][3].

• Problems include overfishing and the risk that deep-sea mining harms marine life. India needs a balanced Blue Economy policy: using the ocean's wealth while protecting the ocean.

• The islands matter for strategy and security:

• The Andaman and Nicobar Islands and Lakshadweep make the EEZ much larger.
• The Andaman and Nicobar Islands sit close to the Malacca Strait.

• Guarding these waters against illegal fishing, smuggling and spying is the job of the contiguous zone and EEZ powers.

• India settles sea borders through international law:

• India accepted the 2014 award on the Bangladesh border as final and binding [4].
• It sent its extended-shelf claims (2009 and 2025) to the CLCS [6].
• This supports a rules-based order in the Indian Ocean. But claims still overlap with Myanmar, Bangladesh, Oman and Pakistan [6], and Indian and Sri Lankan fishermen still cross the border in the Palk Bay.

Related concepts

• Territorial sea
• Exclusive economic zone
• United Nations Convention on the Law of the Sea

Read more

• Maritime zones: territorial sea, contiguous zone, EEZ and continental shelf