Persistent exposure of ocean life to a toxic goo used in offshore drilling spawns a colossal, nearly bulletproof shark that can even move on land. It destroys the oil rig that caused the disaster and then heads for Los Angeles, feasting on divers and threatening to derail a beachside bikini contest.
Dr. Catherine Carmichael, Sarah Lieving, a marine biologist, hires Skipper Chuck, Tim Abell, a local captain with a penchant for drinking, to take her out to Traymore Industries’ oil rig to investigate what happened. Meanwhile, two female lifeguards scheme for drinks and casual sex, and a kite surfer is swallowed by the rising threat—the mighty, almost impervious predator now stalking the coast.
Carmichael collects a water sample and confronts the CEO of Traymore, who invites her for drinks and dinner as part of the uneasy corporate atmosphere surrounding the disaster. In a later interview with the sole survivor from the rig incident, she learns that highly harmful chemicals were used to bore through the rock, and that a shark had pulled the rig down.
Carmichael then asserts to the CEO that a “hydrolizing agent” may have caused the rig to crumble. Simultaneously, the Navy reports a submarine has disappeared, and a search plane spots the super shark circling the sea. At a bar, the two female lifeguards are joined by a male lifeguard as they await the anticipated bikini contest. Out on the open water, Carmichael and Skipper Chuck are circled by the creature until Carmichael, trusting a hunch, tells Chuck to switch off the radio, and the shark mysteriously departs. She theorizes that the fish was drawn to radio waves and the signals that disturbed radio reception.
The bikini contest winner and the runner-up are swallowed on the shore, along with the photographer who had the radio playing, amplifying the sense of a predator exploiting human distractions. The CEO reveals he knows Carmichael has been fired for harassing oil company executives and offers her a briefcase full of money to disappear; she accepts. A despondent Carmichael is later found drunk in a bar by Skipper Chuck, who learns that her brother died in the Exxon Valdez disaster. She passes out and wakes up on Chuck’s boat, shaken but still determined.
Carmichael and Skipper Chuck grow emotionally closer as they seek help from the military, which has devised a remote-controlled walking tank to battle the threat. With a boombox and external speaker used as bait, the super shark is lured to the beach, where the tank’s efforts fail to stop it. In a last, desperate move, Carmichael drops a bomb made of C-4 explosives into the beast’s mouth, and the creature is blown to pieces, ending the terror once and for all.
