Territorial sea

Also called: Territorial waters · Topic: India: Location, Size, Extent and Divisions · NCERT: Class 11, Ch 1 "India - Location"

Meaning

The territorial sea (also called territorial waters) is the belt of sea next to a country's coast, up to 12 nautical miles (about 22.2 km) from the baseline. Over this belt the country has full sovereignty (complete ownership and control) over the water, the seabed, the subsoil and the airspace above it.

It matters because it is the only sea zone that a country treats like its own land. Every other zone further out (the contiguous zone, the EEZ and the continental shelf) gives only limited rights.

Explanation

How the limit is measured

• Baseline: the official coastline from which every sea zone is measured.

• Normally the baseline is the low-water line, the line the sea reaches at low tide.

• The 12 nm line: every point on the outer limit is exactly 12 nautical miles from the nearest point of the baseline [3].

• Nautical mile: the mile used by ships and aircraft.
• 1 nautical mile = 1.852 km = 72,960 inches.
• 1 nautical mile equals one minute of latitude. A minute is 1/60 of a degree, so 60 nm = 1° of latitude.
• This lets a navigator turn a distance on a chart straight into latitude.

• A statute mile (the ordinary mile used on land) is shorter: 63,360 inches, about 1.6 km.

• Conversion: 12 nm × 1.852 km ≈ 22.2 km. (NCERT gives about 21.9 km.)

The law behind it

• India's law came first: 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 [3].

• It already used the 12 nm, 24 nm and 200 nm limits, before any world treaty existed [3].

• 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.
• The territorial sea and the contiguous zone are set out in its Part II.

What rights India has here

• Full sovereignty over four layers:
• the water of the sea belt;
• the seabed (the floor of the sea);
• the subsoil (the rock and minerals under the seabed);

• the airspace above the belt.

• One limit on this power: innocent passage.

• Innocent passage means foreign ships may sail through without stopping, as long as they do not harm India's peace, good order or security.
• Example: a cargo ship sailing quietly past the Gujarat coast is in innocent passage.

• A ship that fishes, spies or pollutes is not in innocent passage.

• Ships only, not aircraft: innocent passage covers ships only. A foreign aircraft needs India's permission to fly over the territorial sea.

Where it sits among the sea zones

Zone	Outer limit (from baseline)	Approx. km	Nature of India's rights
Territorial sea	12 nm	22.2	Full sovereignty, subject to innocent passage
Contiguous zone	24 nm	44.4	Policing only: customs, fiscal, immigration, sanitary, security
Exclusive economic zone (EEZ)	200 nm	370.4	Sovereign rights over resources only
Continental shelf	200 nm, or up to 350 nm	370–648	Rights over seabed and subsoil resources only

• Beyond all of these lie the high seas (water open to all states) and the International Seabed Area (the seabed no country owns).

Where it occurs

• Along India's whole mainland coast: on the Arabian Sea side (for example off Gujarat and Maharashtra) and on the Bay of Bengal side. The belt runs 12 nm out from the baseline [3].
• Around India's islands: the Andaman and Nicobar Islands (Bay of Bengal) and Lakshadweep (Arabian Sea) each have their own sea zones measured from their own coasts.

• The Andaman and Nicobar Islands lie close to the Malacca Strait shipping route, so their waters matter for security.

• Where neighbours' waters meet:

• Bay of Bengal (India–Bangladesh): the sea border was settled by an Arbitration Tribunal under Annex VII of UNCLOS. It gave its award on 7 July 2014, with the Permanent Court of Arbitration (The Hague) as registry. The award is final and binding on both countries [2].

• Palk Bay (India–Sri Lanka): fishermen often cross the sea border here.

• Worldwide: UNCLOS (in force since 1994) sets the same 12 nm limit for every coastal state that has signed it.

Don't confuse with

• Contiguous zone: runs from 12 nm to 24 nm. It gives only policing powers (customs, fiscal, immigration, sanitary, security), with no sovereignty.
• Exclusive economic zone (EEZ): runs up to 200 nm. It gives only resource rights. Other states keep freedom of navigation and overflight there, and may lay cables and pipelines. Sovereignty ends at 12 nm.
• Continental shelf (legal meaning): gives rights only over the seabed and subsoil, not the water above or the airspace. It can extend up to 350 nm with approval from the CLCS (Commission on the Limits of the Continental Shelf, the UN expert body that checks such claims) [4].
• Statute mile vs nautical mile: the territorial sea is measured in nautical miles (1.852 km), not statute miles (about 1.6 km).

Prelims Hooks

• Territorial sea = 12 nm ≈ 22.2 km (NCERT: about 21.9 km). It is the only sea zone with full sovereignty, including the airspace.
• 1 nautical mile = 1.852 km = one minute of latitude. 60 nm = 1° of latitude.
• 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.
• Innocent passage trap: it applies to ships only. Foreign aircraft need permission to fly over the territorial sea.
• India's law came before UNCLOS: Maritime Zones Act, Act No. 80 of 1976, in force on 15 January 1977 [3]. UNCLOS was adopted in 1982 (Montego Bay), came into force in 1994 and was ratified by India in 1995.
• Baseline = normally the low-water line. Every zone is measured from it [3].

Mains Points

• Sovereignty and security (GS-I/GS-III):
• The territorial sea is where India's full law applies at sea. India can act against a ship that fishes, spies or pollutes, because such a ship loses the right of innocent passage.
• The contiguous zone (up to 24 nm) works as a buffer. A smuggler can be caught before reaching the 12 nm line.

• The island territorial seas around the Andaman and Nicobar Islands (near the Malacca Strait) and Lakshadweep need constant guarding against illegal fishing, smuggling and spying.

• A rules-based approach to sea borders:

• India fixed its 12 nm limit by law in 1976, ahead of UNCLOS [3]. It accepted the 2014 India–Bangladesh award as final and binding [2].

• This supports a rules-based order in the Indian Ocean.

• Problems that remain:

• Fishermen cross sea borders, for example with Sri Lanka in the Palk Bay.
• Overfishing puts pressure on coastal waters.
• Both call for a balanced Blue Economy policy (using the ocean's wealth while protecting the ocean) and for agreements with neighbouring countries.

Related concepts

• Maritime zones of India
• Exclusive economic zone
• United Nations Convention on the Law of the Sea

Read more

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