Definitions for "INTERTIDAL"
Strip of coast that is covered or uncovered by the tide.
The zone between high and low tide lines - see also foreshore.
pertaining to the region above the low water mark of low tide and below the high water mark of high tide. This region is covered by water for a portion of every day and is above water for the remainder of every day.
Keywords:  beach, region, sometimes, water
The region of the beach that is sometimes, but not always, under water