The left and right arrow buttons move the boat in the appropriate direction.

The button with the arrow pointing up fires the missiles.

The button with an arrow pointing down releases depth charges.


You cannot use a missile or depth charge until the previous one has hit or missed an enemy.


The buttons labeled x1 and x2 allow you to select the game speed. You need to click one of them to start the game.

The P button pauses the game. To continue the game, press the x1 or x2 button.

The circle and arrow button allows you to restart the game.


The number in the upper left corner of the screen shows the total number of enemy units.

The number in the upper right corner of the screen shows the number of enemy units destroyed.

The number of hearts corresponds to the number of lives of your boat.