(or territorial sea), a maritime zone bordering on the coast or inland waters of a country and constituting part of the country’s territory. The coastal country possesses sovereignty over the surface and depths of the territorial waters, as well as the airspace above them. Territorial waters are regulated by the 1958 Convention on the Territorial Sea and Contiguous Zone (ratified by the USSR on Oct. 20,1960) and by internal legislation of individual countries.
Territorial waters are marked off from the low-water line, either from the borders of inland waters or from baselines. International law does not permit the extension of territorial waters beyond 12 nautical miles. By 1975 about 100 countries had territorial waters extending up to 12 nautical miles. Twenty-two countries, taking advantage of the fact that the 1958 convention left open the question of the extent of territorial waters, unilaterally established wider territorial waters. For example, Brazil, Peru, Sierra Leone, Uruguay, and Ecuador have limits of 200 nautical miles. The USSR supports fixing 12-mile limits for territorial waters but at the same time is ready to recognize the sovereign right of a coastal country to prospect for and exploit fisheries and mineral resources in the sea zone contiguous to the territorial waters, which is called the economic zone. The regulation of these zones should, however, take into account the right of all countries, within the limits of such a zone, to the universally recognized freedoms of the high seas, including the freedom of navigation.
Ships of all countries have the right of innocent passage through territorial waters, provided that the conditions of the convention are observed—that is, the passage must not violate the security of the coastal country, submarines may pass through only if they are surfaced, and so on. A number of countries, including the USSR, have established that foreign military ships may pass through their coastal waters and enter inland waters only with advance permission from the government. The conduct by foreign ships of maritime trade and hydrographic work and research within territorial waters is forbidden by most countries, except under special arrangements.