Pee in the Boat
Two men are adrift in a lifeboat for days. While rummaging through the boat's provisions, one of the men stumbles across an old lamp. When he touches it, a genie comes forth. This particular genie, however, states that she can deliver only one wish, not the standard three. Without giving much thought, one man blurts out, "Make the entire ocean into beer!"
The genie claps her hands and the entire sea turns into brew. The other man looks disgustedly at the one who made the wish. After a long, tension-filled moment, he says, "Nice going! Now we're going to have to pee in the boat."