Continuity mistake: When the shark is attacking the catamarans with the teenagers aboard, in one shot you see Andy fall backwards, still on the catamaran, and he is barefoot. He is then knocked in the water, and when his friends pull him back out of the water on, he now has white trainers on. (01:20:10 - 01:21:15)
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)
Continuity mistake: In the scene when Chief Brody, his wife & deputy come across the sail boat named "Tina's Joy", they find Tina in it, and during this scene Chief Brody's jacket is placed on Tina's shoulders. The Chief then leaves the sailboat in search of the other teens. Later scenes show the Chief wearing this jacket when in fact he left it with Tina.
Continuity mistake: At the end of the movie when the Chief has killed the shark, you see his son Shawn cheering, with his hair completely wet and messed. By the time the Chief paddles over, Shawn's hair is now perfect; dry, and combed neatly...
Continuity mistake: In the scene where Brody drives his jeep onto the ferry he drives it to the edge. Yet in the next shot when it reaches the other side the jeep is about two feet from the edge.
Continuity mistake: At the beginning of the film when the shark attacks the divers, you see in one shot that the shark already had a burned scarred face. The shark doesn't get set alight until later in in the film. This scene was one of the last ones to be filmed.