UNCLOS Rules on Territorial Sea, EEZ and Freedom of Navigation

Under international maritime law, particularly the United Nations Convention on the Law of the Sea (UNCLOS), 1982, coastal states have defined rights over different maritime zones extending from their coastlines.

Territorial Sea

Every coastal state can claim a territorial sea up to 12 nautical miles from its coast, measured from a legally defined baseline.

Within this zone, the state exercises full sovereignty, including over:

• The sea
• The airspace above it
• The seabed and subsoil

However, this sovereignty is subject to the Right of Innocent Passage, which allows foreign ships to pass through the territorial sea as long as they do not threaten the security of the coastal state or violate its laws.

Exclusive Economic Zone (EEZ)

Under UNCLOS, coastal states can claim an Exclusive Economic Zone (EEZ) extending up to 200 nautical miles from the same baseline used to measure the territorial sea.

Unlike the territorial sea, the state does not exercise full sovereignty in the EEZ. Instead, it enjoys sovereign rights for exploration, exploitation, conservation, and management of natural resources, including:

• Living resources (such as fish)
• Non-living resources (such as oil, gas, and minerals)

Continental Shelf

Countries may also claim rights over the continental shelf, which can extend up to 350 nautical miles from the baseline, depending on geological and technical criteria defined under UNCLOS.

In this zone, states have sovereign rights over seabed resources, but not full sovereignty over the waters above.

Freedom of Navigation

According to Article 87 of UNCLOS, all states enjoy the Freedom of Navigation and Overflight beyond the outer limit of the territorial sea.

In the reported case, the Iranian naval vessel IRIS Dena was operating about 20 nautical miles west of Galle in Sri Lanka, which lies within Sri Lanka’s EEZ but outside its territorial sea.

Therefore, under UNCLOS provisions, both IRIS Dena and the United States Navy submarine were not required to obtain permission to transit through Sri Lanka’s EEZ, as navigation in this zone remains open to all states.

Source: IE