Continuity mistake: When Brody is with the photograph developer, who is developing the divers photos for him, he takes a photo from a box and puts it in a tray of liquid, and he then puts the lid of the box on properly. Then in following shots the box lid alternates from on properly, to off slightly. (00:49:00)
Continuity mistake: Brodie is racing in his vehicle down the beach to investigate an incident, driving to our left. He then gets out of the car and is shown running down the beach to the left. Unfortunately, the scene was shot with Brodie running to the right. The editor simply reversed the film so Brodie would be running the right direction. You can see backwards writing for about 2 seconds.
Continuity mistake: After Chief Brody is fired from his job, he comes home drunk. No beer cans can be seen spilling out of his car or on the ground. The next day when he is taking his wife to work, there are several empty beer cans on the ground. Where'd they come from?
Continuity mistake: Chief Brody and his raft disappear from under the shark when it catches fire. Understandable, as they were burning the model shark for real, but still poorly edited.
Continuity mistake: In the beginning of the movie when Terry is water skiing, the boat has a 70hp 3 cylinder Johnson. When the shark is eating the boat it's a 1977 55 horsepower motor that still has the 70hp decal on it.
Continuity mistake: Brody has a hold of the large power line, and the shark is gliding along straight for it. In all the shots of Brody holding the power line, the green jacket he wears has wet splashes on it. One patch of water on his right shoulder briefly disappears for one shot, the reappears in the following. (01:46:45)