Island
An island or isle is any piece of sub-continental land that is surrounded by water. Very small islands such as emergent land features on atolls can be called islets, skerries, cays or keys. An island in a river or a lake island may be called an eyot or ait, and a small island off the coast may be called a holm. A grouping of geographically or geologically related islands is called an archipelago, such as the Philippines.
Okinotorishima
Under the United Nations Convention on the Law of the Sea, an island is "a naturally formed area of land, surrounded by water, which is above water at high tide". It states that "rocks which cannot sustain human habitation or economic life of their own shall have no exclusive economic zone." Japan signed the Convention in 1983; the Convention came into force in 1994–1996 for Japan.