A cay (also spelled key, but both are pronounced alike as "key" href="http://articles.gourt.com/en/IPA">IPA /ki:/) is a small, low island consisting mostly of sand or coral. The word is used almost exclusively in the Caribbean, though it is sometimes used in the context of other tropical environments, such as the Great Barrier Reef and especially in the Florida Keys.

Sand cays are formed when tidal action, wind and sea birds deposit, over a long period of time, coral debris and sand onto reef flats, usually on the leeward side of the reef, but occasionally on the windward side. weather affects the formation of cays greatly; large tides would bring much more debris onto the cay and thus make it larger, while a hurricane could completely obliterate a cay.

An example of a coral cay is Heron Island.

Landforms

Cay | Cayo