They just cannot shake that shark. In this third fishy sequel to Steven Spielberg's classic "Jaws," Lorraine Gary returns, as Roy Scheider's widow from the original flick. When her son, the current police chief of shark-plagued Amity, is also killed by the beast, mom heads to the Bahamas to be with her surviving son. Lance Guest and Mario Van Peebles co-star as marine biologists who want to help but it's up to mom and Michael Caine as her new beach-bum lover to catch the vengeful great white shark with the big mouth.