In this game your goal is to win more battle rounds than the computer within the set amount of time. In each round, you can choose your strategy of either destroying the red fleet or taking out the red sub. You must do this before the red sub does the same to you. Choose the level of difficulty (Admiral or Ensign) with and set the duration that the game will be played with . Press to start the game.

Use the joystick to move your sub and . Press to submerge and to surface. Press the button to fire torpedoes. You can only shoot a maximum of eight torpedoes before you have to reload your firing tube. The center arrow indicator tells which direction your traveling and how fast.

Each type of ship in the enemy fleet takes a different number of hits to sink. Use the sonar screen above to determine your position and the positions of the two fleets. The top green bar indicates the strength of the red sub and the lower green bar is the status of your sub. If either goes completely red, that sub is sunk. As you take on damage, certain aspects of your sub will fail, like the target assist computer or torpedo reloads. You can submerge to either escape from being torpedoed, or to sneak up on the enemy submarine. However, you cannot fire torpedoes unless you're on the surface.

The white bar indicates how much time is left in this particular round of play.