Jaws franchise is the perfect example of sequel fatigue. In the span of one series, you go from the first film, widely recognized as one of the most popular, well-made monster films in history, to the 4th film, widely regarded as one of the worst films in existence.
For all its faults though, I do have a big soft spot for Jaws II, though it suffered in not having the same or a similar dynamic trio to the first film's protaganists. Mrs Brody and the deputy were great, but they were no Robert Shaw and Richard Dreyfuss. It also breaks some of the rules established in the first film. You'll notice if you watch the first one closely, that the theme music actually only plays when the shark is around. In Jaws II, there's one or two cheap moments where they use the music to build tension, only to establish a false jump scare. The scene when Brody finds the burnt body in the surf, for example. Also, the camera angles in this shot imply the shark is actually watching Brody. The movie is actually borrowing more from slasher movie tropes than the original did. Then there's Brody's laughable suggestion that the Jaws II shark is actually killing for revenge. While it's basically a throwaway line, it's enough to establish the silly premise that each sequel involved vengeful sharks chasing Brody family members. I much prefer the original film where the shark has no real motives beyond hunger.
Had I written Jaws II, I'd actually have followed Hooper's character instead of Brody, and maybe had it set on one of his research vessels. this would make more sense, as it's believable with Hooper's line of work as a marine biologist. It would basically involve a similar plot to the first film, but at least it would be a more plausible premise and not a complete rehash of the first film.