The game is presented as a submarine command simulation with navigational and tactical displays. The player steers the boat, manages speed and depth, searches for targets, identifies ships, and conducts torpedo attacks.

Missions are built around patrol operations. Success depends on approaching carefully, conserving fuel and torpedoes, coordinating the crew, and diving or maneuvering to evade escorts after an attack. Progression is tied to completing patrol objectives rather than a conventional character-level system.

Use patience instead of attacking every contact. Identify targets before firing, preserve torpedoes for valuable or vulnerable ships, and keep an escape route in mind.

After an attack, change depth and course promptly to reduce the effectiveness of pursuing escorts. Conserve fuel during patrols and avoid exposing the submarine unnecessarily when the tactical situation is unclear.