Jack Chester, an overworked air traffic controller, takes his family on vacation to the beach. Things immediately start to go wrong for the Chesters, and steadily get worse. Jack ends up in a feud with a local yachtsman, and has to race him to regain his pride and family's respect.

This third film in the series follows a group of marine biologists attempting to capture a young great white shark that has wandered into Florida's Sea World Park. However, later it is discovered that the shark's 35-foot mother is also a guest at Sea World. What follows is the shark wreaking havoc on the visitors in the park.