This is a great game for your underwater party - it's called Sharks and Fish. First, fill a washing-up bowl with sand. Cut out lots of fish shapes, and a few shark shapes. Bury the shapes in the sand. Get your party guests to bury their hands in the sand and pull out a fish or a shark. If they pull out a fish, they get a prize. But if they're unlucky and get a shark, they have to do a forfeit. And if you're stuck for forfeit ideas, why not get them to sing the number one song, do an impression or recite the alphabet backwards. Or maybe set them a physical challenge like patting their head and rubbing their tummy at the same time, or eating a doughnut without licking their lips! Heh heh - have fun!