Box Office Bomb: This Jaws film was the first and only one to fail in American theaters, grossing $20,763,013 against a $20 million budget and an additional $3 million in marketing costs. But it made enough money internationally to make more than its budget back (albeit just barely).
Creator Killer: Emmy Award-winning director Joseph Sargent (he made the 1974 version of The Taking of Pelham One Two Three) was nominated for the Razzie for Worst Director for his work on the film; he was mostly relegated to TV movies for the remainder of his career. Screenwriter Michael de Guzman likewise spent the rest of his career in television, with no theatrical movie credits before or after this.
Dawson Casting: 9-year old Judith Barsi as 5-year old Thea Brody. (She had a growth deformity that made her look much younger than she was)
Executive Meddling: The film's original ending made a little more sense, but was changed for overseas prints due to the poor performance in theaters. Yes, the impaled shark ending was used in original theatrical prints.
Franchise Killer: One of the most infamous examples, and one of the few films on Rotten Tomatoes to have a 0% approval rating. After this attempt to extend the Jaws series was sent to the bottom of the ocean floor, Universal finally stopped making these movies and have not attempted to make a new film.
Money, Dear Boy: Michael Caine only appeared because of it. And later regretted being in the Bahamas shooting it instead of picking up his Academy Award for Hannah and Her Sisters. He's never even seen the film — but he assures that it paid for a lovely house! note Though, if it's any consolation, he was able to pick up his second Oscar for The Cider House Rules.
This is also the reason for his notorious instantly dry shirt after climbing onto the boat. In the heat of the Bahamas it dried out between takes, and when no one else noticed he elected to remain comfortably dry rather than point it out.
Michael Caine generally prefers not to acknowledge his involvement in the film. As mentioned above, he's never even watched it, but is well aware of its terrible reputation. Universal became aware of that reputation immediately, and embraced it, allowing Steven Spielberg to launch a Take That! to this movie in the second Back To The Future film.
Director Joseph Sargent did an interview with the Television Academy in 2006 when he was questioned about making this film. Judging by his expressions while answering the question, it appears that he wasn't very fond of it either.
Although she had been mostly retired from acting for eight years prior to appearing in the film, and gave it up completely after its release, it was still a sad last effort for actress Lorraine Gary, who got a Worst Actress nomination for her performance.
One could also argue that she did it as a favor for her husband, Sidney Sheinberg, who was head of Universal Pictures at the time.
It was one of many box-office bombs that helped set back Michael Caine's career for a brief time, until he had a Career Resurrection in the late 1990's.
Lance Guest had looked like he might have a promising career after playing the title character in The Last Starfighter. After his performance here was soundly trashed by critics for his Dull Surprise acting, he's appeared in a grand total of two theatrically released films.
Roy Scheider was originally asked to reprise his role as Martin Brody, but he flat-out refused to come back when he saw that his character was there just to be killed off in the first minutes. That's right - Sean's death scene was originally intended for Martin. Murray Hamilton was also asked to appear, but died before any serious work began on the screenplay.
The studio considered making the film in 3D — which would have made this the first film franchise to have two 3D sequels — but worries about the cost of shipping the 3D film cameras to the Bahamas and keeping them working properly in the tropical climate nixed that idea.
The infamous "Exploding Shark" ending was a hasty reaction to poor testings of the original ending, where the shark was impaled by the boat. Another bit hastily changed was the fate of Jake, who originally died during the ending. Test audiences were upset by this, and it was changed so that he lives (though the footage of him being mauled by the shark was left in anyway, making his survival quite the Ass Pull).
Earlier drafts of the script (titled Jaws: The Return) re-used the "kill the shark via electrocution" ending of Jaws 2, which was likely changed due to the film-makers wanting something different, and the script depicting it in such a way that it would also have killed Ellen as well. Other drafts had the shark being the shark from the second film out for revenge, the offspring of the shark from the second film out for revenge, or a witch doctor using the shark as a tool for revenge. The witch doctor version was used in the novelization.