From the instructions: Take control of a little guy in scuba gear as he explores the sea from his boat, looking for hidden treasures! As you swim about (avoiding the assorted marine-life), you will find clams on the ocean bed. When they open their shells, swoop down and grab their pearls! Return these pearls to the ship to earn points. Watch out for you air level - you'll need to return to the boat when it gets low, but the boat doesn't stay still - it moves!