Territorial Waters Law and Legal Definition

The territorial waters are sea waters of a state near the shoreline of a body of fresh or salt water that are regarded as under jurisdiction of the state. Territorial waters are the inland waters, waters between the mean of high tide and low tide, and all water that extend seaward, typically to 12 nautical miles (22 km) from the coast, under the United Nations Convention on the Law of the Sea.

Territorial waters claimed by one state are often disputed by another state. Territorial waters have often been subject to arbitrary extension in order to give a state authority over such activities such as offshore oil exploration, fishing rights and to prevent pirate radio broadcasting. Merchant ships of all flags have the right of “innocent passage” in a nation’s territorial waters; the rights of nonbelligerent foreign warships in this zone, and the extent of the jurisdiction of the coastal nation’s courts over ships passing through and incidents in the zone, have historically been controversial.