Continuity mistake: In one of the final scenes in which the shark is attacking, the colour of the water is not consistent in the background. In one scene it is light blue, and in the other it is much darker blue.
Continuity mistake: When Ellen is on the boat, and sees the shark coming towards her, the distance between her and the shark does not look very far. When it cuts to Mike, Jake and Hogie in the plane, from their view the distance between the boat and shark looks much greater, about 60-70 metres. Also, only about five seconds later, the shark jumps out of the water and strikes the boat, the shark could not have swam that distance in such a short time.