shoal


shoal (http://definr.com/shoal)

     adj : full of submerged reefs or sandbanks or shoals; "reefy
           shallows"; "shoaly waters" [syn: reefy, shelfy, shelvy,
            shoaly]
     n 1: a sandbank in a stretch of water that is visible at low tide
     2: a stretch of shallow water [syn: shallow]
     3: a large group of fish; "a school of small glittering fish
        swam by" [syn: school]
     v 1: make shallow; "The silt shallowed the canal" [syn: shallow]
     2: become shallow; "the lake shallowed over time" [syn: shallow]