Sharks and Minnows
Sharks and Minnows is another oldie but goodie. One person is the shark, and the rest of the players are minnows. The shark camps out in the middle of the pool, and when cued, the minnows dive in and try to make it past the shark. The game's over when all of the minnows have been snagged, and the first person caught becomes the shark in the next round.