A military ship crashes and two divers go searching for it only to be killed along with their captain, by a large tiger shark that was a passenger on the ship and created by the Navy. When one of the bodies washes ashore, an autopsy shows a large fish killed him, causing local authorities to want to close the beach and postpone the local Regatta. the Mayor ignores their warning, and the shark reins terror down upon the beaches of Hampton Bay, Florida.