In the game, players command fleets of naval vessels attempting to invade the harbor of their opponent.

During the game's "strategy phase," players can only see the location of enemy fleets on the screen, and not what ships are within them.

Players take control of their respective flagships and attempt to sink the ship(s) in the opponent's fleet.

Combat ends and the game returns to the strategy phase when all ships in one player's fleet are destroyed.

Gameplay continues in this fashion until one of the players directs their aircraft carrier or troop transport into the opponent's home port, thus successfully invading it and winning the game.

Aircraft carriers and troop transports are slow to move and weakly armed, but are well armored and are necessary to capture the opponent's home port.

Battleships and destroyers are well-rounded escort vessels, while submarines and PT boats trade armor strength for speed and attack power.