Billy Deep and his sister Sheena are spending another summer in the Caribbean on their uncle's floating lab. They are great swimmers. But even great swimmers ge... » 

Billy Deep and his sister Sheena are spending another summer in the Caribbean on their uncle's floating lab. They are great swimmers. But even great swimmers get into trouble. This year there's something really scary going on under the sea. The fish all seem to be growing - bigger and bigger into monster-sized sea creatures. «