The use of the term “territorial waters” herein is that generally applied in international law to the strip of water where the open sea washes the edge of the land territory of a state, within which strip the state has certain jurisdiction over its own nationals and those of other states. It does not include more extensive strips of water over which some states have asserted jurisdiction for certain purposes over their own nationals or in which, by treaty, adjoining states have asserted jurisdiction over the nationals of both.

There is no generally accepted rule of international law which may be regarded as universally applicable with respect to the right of dominion or jurisdiction over a particular belt of ocean adjacent to a country. It may be said at the beginning, however, that most countries have abandoned the old theory of Mare Clausum, under which coastal waters were sometimes fixed at sixty miles, one hundred miles, two days' journey, etc., from the shore, and under which claims were also made by agreement between two or more countries over an ocean common to them. In the decision of the Permanent Court of Arbitration at the Hague (1910), a member of the Tribunal referred to Selden's doctrine of Mare Clausum and to certain ancient treaties based upon it as “wild, obsolete claims over the common ocean which all nations have of old abandoned with the progress of an enlightened civilization.” In the early nineteenth century Russia claimed the Behring Sea as Mare Clausum. This was protested by Great Britain and the United States of America, and in treaties in 1824 and 1825 with the United States of America and Great Britain respectively, Russia recognized that “jurisdiction in the said Sea should be regarded as the reach of a cannon shot from the shore.” It may be of interest to note, however, that the theory is not entirely dead, for within even recent years Russia has applied it to the White Sea, with such effect that Norwegian sealing ships can no longer operate in this area.