Maritime Zones and the Law of the Sea

A ladder of zones, each granting less control than the one before it

The United Nations Convention on the Law of the Sea (UNCLOS), finalised in 1982 and in force from 1994, sets out a series of maritime zones measured outward from a coastal state's baseline (broadly, its low-water coastline), and the exam-relevant discipline is keeping the exact distance and the exact degree of control attached to each zone straight, since a question routinely tests one zone's true figure by attaching it to a different zone's name.

• The territorial sea extends up to 12 nautical miles from the baseline. Within it, the coastal state holds full sovereignty, extending to the seabed, subsoil and airspace above, subject to one universal limitation: the right of innocent passage, which lets a foreign ship (not aircraft) pass through without stopping, so long as the passage does not threaten the coastal state's peace, security or good order. A statement denying this right of innocent passage to other states, or extending it to foreign aircraft, is testing this exact limitation.
• The contiguous zone extends to 24 nautical miles from the baseline (that is, a further 12 nautical miles beyond the territorial sea), where the coastal state's control narrows to specific enforcement purposes only: preventing and punishing infringement of its customs, fiscal, immigration and sanitary laws, not the full sovereignty of the territorial sea.
• The Exclusive Economic Zone (EEZ) extends to 200 nautical miles from the baseline. Here the coastal state does not hold full sovereignty either, only sovereign rights over exploring, exploiting, conserving and managing the zone's living and non-living natural resources (fisheries, oil, gas, minerals), while other states retain freedom of navigation and overflight through it.
• The continental shelf, as a legal zone under UNCLOS, is a distinct concept from the same term's use in physical geography for the seabed's bathymetric gradient (covered in the Geography spine's own note on the ocean floor). Legally, it comprises the seabed and subsoil extending to the outer edge of the continental margin, or to 200 nautical miles where that margin does not reach that far, and can extend further, up to 350 nautical miles (or 100 nautical miles beyond the 2,500-metre depth contour), with the UN Commission on the Limits of the Continental Shelf's approval. The coastal state's rights here cover the seabed and subsoil's resources specifically, distinct from the EEZ's water-column resources like fisheries.

A question that states "all three" of the territorial sea (12 nm), the right of innocent passage, and the EEZ (200 nm) as correct is testing whether these figures and rights have been kept straight rather than blurred into one generic "India's waters" idea, since each is independently, precisely true.

India's own law predates UNCLOS itself by six years

India gave these zones domestic legal effect through the Territorial Waters, Continental Shelf, Exclusive Economic Zone and Other Maritime Zones Act, 1976, notably enacted before UNCLOS was even opened for signature in 1982, reflecting the customary international law and state practice already emerging around these zones at the time; India ratified UNCLOS itself only later, in 1995, after the Convention entered into force. The 1976 Act mirrors the distances above in domestic law: Section 3 fixes the territorial sea at 12 nautical miles, Section 5 the contiguous zone at 24 nautical miles, and Section 7 the EEZ at 200 nautical miles, with the Union holding sovereign rights over the EEZ's resources. A statement suggesting India's maritime zones were only legally recognised once India ratified UNCLOS is testing this sequencing: the domestic Act came first.

Quick revision points

• Ladder from the baseline outward: territorial sea (12 nm, full sovereignty, subject to innocent passage) → contiguous zone (24 nm, limited customs/fiscal/immigration/sanitary enforcement only) → EEZ (200 nm, sovereign rights over resources, not full sovereignty) → continental shelf (legal concept: to the margin's edge or 200 nm, extendable to 350 nm with UN CLCS approval).
• Right of innocent passage applies to foreign ships through the territorial sea only, not aircraft, and not through internal waters.
• India's Territorial Waters, Continental Shelf, EEZ and Other Maritime Zones Act, 1976 predates UNCLOS's 1982 signing; India ratified UNCLOS only in 1995. The Act's own Sections 3, 5 and 7 fix the 12/24/200 nautical-mile figures in domestic law.