An American oil tanker captained by Capt. Steve Jarvis (Raymond Massey) is sunk in the North Atlantic Ocean by a German U-boat. Along with First Officer Joe Rossi (Humphrey Bogart), they make it to a lifeboat loaded with other crewmen. When the U-Boat crew starts filming their plight, they respond with rude gestures, and their lifeboat is rammed by the sub. The survivors swim to a raft and are finally rescued after eleven days adrift.