sentences:  Australian survivors detect an incomprehensible Morse code signal coming from the presumed dead West Coast of the United States.The American nuclear submarine, USS "Sawfish", now under Royal Australian Navy command, is ordered to sail north and make contact with the sender of the Morse signal.The submarine is commanded by Capt Dwight Towers (Gregory Peck), who leaves behind a new friend, the alcoholic Moira Davidson (Ava Gardner).