You play as a fleet commander and your task is to escort a convoy from one end of the map to the other within a set time limit, with at least half the convoy vessels surviving the U-boat wolfpack hiding in the depths.

The fleet commander has six destroyers for protecting the convoy and clearing the sea of submarines. The ships are equipped with sonar to discover the submarines and a number of depth charges and torpedoes to destroy them with. Only a limited amount of moves may be made during each turn.