According to 33 USCS § 2105 (1), the term artificial reef means “a structure which is constructed or placed in waters covered under this title for the purpose of enhancing fishery resources and commer [..]

A submerged structure placed on the seabed deliberately to mimic some characteristics of a natural reef

Any man-made structure that is submerged, or partially submerged, at any stage of the tidal cycle. It may be placed by design for a multitude of purposes, eg piers, jetties, coastal defence, fishery e [..]

An underwater structure made of artificial substances (such as concrete or metal) that mimics oyster reefs and provides habitat for aquatic species that live on or around aquatic reefs.