Why was there such a large break between “Jaws 2” and Jaws 3”?

The break between “Jaws 2” and “Jaws 3” is the largest break in the series, and I’m wondering why. I wonder if it had to do with Zanuck and Brown disagreeing on Universal on which direction to take the franchise (Zanuck and Brown wanting to do a National Lampoon style spoof, and Universal wanting to make more of a straight, serious sequel). I could see that taking some time, though not necessarily five years. Since “Jaws 2” was a big hit, it seems like Universal would have wanted a third film to come out within (say, for example) three years. I wonder if the change in producers added to the wait, or if negotiations with Sea World took a while, or if the process of shooting the film in 3-D made for a prolonged production. These are just my ideas. Does anybody have any definitive knowledge on why it took five years for “Jaws 3” to come out?