27 mai 2018 · A beach is a repository of sediments unconsolidated ranging from sand and gravel, excluding the mud as it is not an alluvial plain or coast mangrove, which extends from the base of the dune or the limit where the vegetation ends to a depth where sediments no longer move. This depth varies between beach and beach depending on bathymetry, geomorphology and waves. The Barceloneta beach is the.