A Semester at Sea ship is attacked and sunk by a mutated two-headed shark, and the survivors seek refuge on a deserted atoll. The coeds, however, are no longer safe when the atoll starts flooding.

The world’s greatest killing machine is three times as deadly when a mutated shark threatens a cruise ship. As the shark eats its way from one end of the ship to the next, the passengers fight the deadly predator using anything they can find.

A beautiful island is home to thousands of species of aquatic life. Now there is a new species: the 5-Headed Shark is all heads and teeth. Shaped like a demented starfish, this monster terrorizes the open ocean before invading the beaches of Puerto Rico, endangering the once peaceful island paradise.

What is supposed to be a marriage boot camp on a remote island turns into the ultimate test for survival when a 6-headed shark starts attacking the beach. Trapped with minimal weapons they try to fight off the shark, but quickly discover that no one is safe in the water or on land.