Hit the beach ball back and forth with your opponent. You will lose a point if the ball drops to the water on your side, or if you hit it out of bounds. The same goes for your opponent. The first to eleven points wins, but you must win by two.
Play against eight opponents in tourney mode, or just choose quick play. If you beat the game, you can change your dolphin's color by clicking 'next opponent' after defeating Wendy the White.