ANTI-SUB PATROL is a tactical pursuit game where you, as head of a squadron of destroyer escorts, attempt to rid the waters of two submarines who, at the same time, are trying to destroy you. You are equipped with sonar, a course finder, and unlimited depth charges. The subs, on the other hand, are capable of silent running, evasive maneuvers, or firing torpedoes.
If everything began well, you should receive a STAND BY signal from fleet command. You start out with three destroyers under your command, which you deploy one at a time. Your goal is to find and destroy an enemy sub hidden somewhere on the display grid.