Placer

Placer is a term used by Portuguese and Spanish navigators and cartographers to refer to a certain kind of submerged bank or reef. Commonly the bottom of such a reef is sandy, but there are some where the bottom is muddy or stoney. Although most reefs designated as placer are flat and shallow, exceptionally there are some that do not share those characteristics and are known as placer acantilado. A placer usually provides an anchorage for seagoing vessels.