In this popcorn sci-fi action thriller, three genetically mutated, super-intelligent sharks stalk the marooned members of an underwater research facility. A B-movie cast struggles gamely with the hopelessly mundane dialogue, but director Renny Harlin's submerged Cliffhanger remains afloat through sheer nerve, technical prowess and some truly spectacular shock moments involving computer-generated special effects. The tricks of the trade invented by Steven Spielberg for Jaws are all present and correct, but merely placed on a far bigger hi-tech canvas. The result is a gory, trashy blockbuster that succeeds despite its waterlogged script.

Researchers on the undersea lab Aquatica have genetically altered the brains of captive sharks to develop a cure for Alzheimer's disease. But there's an unexpected side effect: the sharks got smarter, faster, and more dangerous. After a big storm damages their remote research facility, they must fight for their lives.