Player controls the submarine which is fully maneuverable beneath the surface. If it comes to the left edge of the
screen, it will emerge on the right edge. Torpedoes can be fired upward at ships on the surface, or at enemy submarines.
Tugboat ships in first lane must be avoided. If a torpedo hit them it will bounce back to the submarine.
The player's submarine has a limited energy and torpedoes supply, so both must be frequently replenished. This can be achieved with collecting the help of a supply that appears occasionally. The player must intercept the package before it hits the surface or get destroyed from enemy torpedo.