A man stranded on an island builds a raft to try to escape to another island where people may be living hopeing to get help back to the America. The man was terribly afraid of sharks so upon approaching another island, he spots a man and calls out to him, "are there any sharks in the water?" the second man calls back "no".
The first man then proceeds to leap into the water so as to swim ashore, halfway there he yells out to the man on the island..."why arn't there any sharks in the water?"
The man replys, "Because the alligators ate them."