A port of the 1975 PC-50X Game Submarine, similar type games were also in the arcade and are ports themselves from Electromechanical games. Choose either the Submarine (Blue) or Destroyer (Green) and attempt to shoot each other with missiles. Submarine can also hit the Escort (Red) ship that is protected by the Destroyer. Plunging down the controller fires, Push Left / Right for Left and Right movement on screen respectively. Game ends when one side reaches 15 points.