If you like really bad shark movies, then you must see 2-Headed Shark Attack. It has Brooke Hogan, Carmen Electra and Charlie O'Connell. It's so awesomely bad and can be found on Netflix.
From IMDb: "Survivors escape to a deserted atoll after a Semester at Sea ship is sunk by a mutated two-headed shark. But when the atoll starts flooding, no one is safe from the double jaws of the monster as it eats fresh delicious women and men." www.imdb.com/title/tt2043757/