Some geologists consider a beach to be just this shoreline feature of deposited material, but William Bascom (1980) has argued that a beach is the entire system of sand set in motion by waves to a depth of ten meters (30+ feet) or more off ocean coasts. Submerged, longshore bars are therefore also part of the beach. In the Bascom approach, beaches can be viewed either:
small systems in which the rock material moves onshore, offshore, or alongshore by the forces of waves and currents; or