A crucial subplot involves Michael Caine's character smuggling drugs onto the island. The scenes were shot, then deleted during post-production because it took away from the film's main premise involving the shark. It's fully detailed in the film's novelization.
The original script features a cameo for Richard Dreyfuss's character from the original Jaws (1975), marine biologist Matt Hooper. In Hooper's scene, he calls the Brodys and is greeted on the phone by Thea, who knows him as "Uncle Matt". Hooper is established as being close to Michael and Carla, who calls him "my second favorite marine biologist", and he gives them his condolences about Sean's death. Hooper and Michael discuss their careers, the late Martin Brody, and Hooper's once spending Christmas with the family with Martin dressed as Santa Claus. The scene ends when Michael heads off to summon Ellen to the phone to talk to Hooper.
When Michael returns home to his mother's after his brother is killed, in her living room are several guests, including Lee Fierro. Fierro played Mrs. Kintner in the first Jaws (1975) and her son 'Alex Kintner' was the second victim killed by the shark. Fritzi Jane Courtney who played Mrs Taft in the first two Jaws films is also present.
The movie's main tagline "This time it's personal" was parodied in Back to the Future Part II (1989) where the fictional "Jaws 19", directed by Max Spielberg, has a movie poster that says, "This time it's REALLY personal!". The phrase "This time it's personal" has since become a cliché tagline for a number of sequel movies.
The only Jaws (1975) sequel not to be numerated (unlike Jaws 2 (1978) and Jaws 3-D (1983)) which would have had it called "Jaws 4", which was actually a working title for the movie and still acts as an informal title for the picture. Another working title for the film was "Jaws 87", which is the year it was released in.
Actress Lorraine Gary appeared as Ellen Brody in three of the four films in the "Jaws" film franchise, as did supporting actress Fritzi Jane Courtney who played her friend Mrs. Taft. Jaws 3-D (1983) was the only one that neither actress appeared in. That movie was also arguably the only one that Roy Scheider did not appear as well. He appeared in the first two films, and was seen in "Jaws: The Revenge" but only via the inclusion of a framed photograph and archive footage used for flashbacks.
Set mostly in the Bahamas, the film's storyline includes its Junkanoo Festival, previously known to cinema-goers from also featuring in the earlier James Bond movie Thunderball (1965). The annual parade is also featured in the later movie After the Sunset (2004).
The trivia items below may give away important plot points.
Each Jaws movie plants the method of the shark's destruction earlier in each film. In Jaws, Hooper warns Brody about the air tank "blowing up if you screw around with it." In Jaws 2, Hendrix and the old man find the power line which later electrocutes the shark. In Jaws 3, an argument ensues about Philip FitzRoyce using grenades. In this film, Jake is working on a transmitter that sends out high frequency.
The Theatrical Version's ending, in which the shark head blows up, reuses footage from the first picture's ending, in which the headless bleeding shark sinks. The ropes from the barrels Quint used are still there.