The last thing you want to see when you're out on the water is a shark swimming around looking for lunch. A woman was out surfing in Australia when she spotted a shark, and immediately starts paddling towards land like a madwoman! She's having fun though, laughing the whole way to the shore.
This next guy didn't find his situation as humorous. Dimitri Maramenides was out kiteboarding, when suddenly the wind was gone, leaving him stranded in shark-infested waters with no one around. Finally, a boat comes by but can't help him. They offer to call the coast guard, to which Dimitri says no, but just a couple seconds later he feels a bump against his leg, and suddenly he's not so confident anymore.