Ellen Brody: That's your third smoke already!
Martin Brody: With coffee...
Ellen Brody: Try a donut.
In the scene where Brody approaches the group of teenagers on their smashed boats, the angle cuts to show Brody approaching seen as if from Cable Junction. At this point, there is a huge mistake. The teenagers' boats are clearly visible in the foreground, the kids have all completely vanished, and you can spot the cameraman standing on the boats quite clearly.
At one point, the camera team filmed a scene where the teenagers were filmed from a distance calling for help. What the crew didn't realise was that the actors were really calling for help - a group of hammerhead sharks had begun circling their raft.