As with all single screen solar powered games by Bandai, this game makes efficient use of its single screen so that it can show two different scenes. First you are shown a ship that drops a depth charge that damages your submarine at the bottom.
The
next scene shows the inside of the submarine where water is starting to run
in. Your job is to stop the leaks with your bear hands, the water leaks in at
four different places and it is really difficult to judge which leak you should
stop first, running from left to right and back again without thinking doesn't
seems to be the a bad strategy here strangely enough.
After
you've stopped 500 points worth of leaks, your submarine is repaired and ready
to do battle with the ship that bombed you in the first place. You can send
torpedoes up to sink it, the ship is still dropping depth charges which if it
hits you sends you back to the scene in the submarine again. There is a shark
in between the submarine and the ship which neutralizes your torpedoes, but
lets the depth charges pass. A fun game.