Continuity mistake: Throughout the film, there are abrupt changes concerning the position of the sun's shadow, or going from being windy to not, or being overcast to bright and sunny, or where the water is either at a dead calm or pretty rough, all between consecutive shots within a scene. (00:15:15 - 01:21:30)
Continuity mistake: After the two barrels are tied off, there is at least twenty feet of line between the barrels and where it disappears into the water. When the next harpoon is shot (the barrel shatters the cabin window) and the shark pulls Orca, that last barrel trails way ahead of Orca, its taught line being extremely shorter than the lines leading to the two other barrels, though the shark pulls them at the same time. However, once the cleats break off, the length of the three lines are identical in length. (01:44:15)
Visible crew/equipment: Just after the two barrels pop up, Hooper comes down from the bridge deck and quips, "Now what?" In the next shot as the two barrels bob up and down, Orca is in the distance with Quint up on the bridge deck and Hooper and Brody on deck at the stern - someone else is moving in the cabin, beside the hanging net.
Continuity mistake: When the shark enters the Estuary, he passes Sean playing on the sand. After the attack Michael is pulled ashore and there is a close-up of Sean crying. Behind Sean the orange and white stripe cabanas are visible. However, there are no cabanas at the shores of the pond; these cabanas are located at the main beach area. The footage of Sean, with the cabanas behind him, is from the earlier scene of Alex's attack. (01:02:00 - 01:03:30)
Continuity mistake: While Brody and Quint are talking in the cabin, just after Hooper sticks his tongue out at Quint, the books on the shelf are fallen over on their sides. However, in the next shot when Quint walks out on deck, the books are visible behind him and now they're upright. (01:19:45)
Continuity mistake: In the council chambers, after the Mayor says, "Only 24 hrs," as the people argue in the wideshot a particular area of the chalkboard is visible behind them and it is blank. In the very next close-up Quint, who was not in the previous shot, scrapes the board with his nails, which now shows the large doodle of the shark, that should have also been visible in the previous shot, but was not. (00:20:30)
Continuity mistake: Just as Quint shouts, "You may be a big yahoo in the lab, but out here you're just supercargo..." and when he asks Brody to unbuckle him, the cleat at the stern has plenty of line wound round it and there is a red cup beside it. However, in the previous and following consecutive shots within this scene, there is no line and no cup. (01:17:50)
Continuity mistake: While Quint leads the shark into the shallows, Brody asks, "Have you ever had a Great White do this?" and Hooper is beside the foremast holding one of the rungs, directly under the crow's nest. However, in the next shot, he stands at the edge of the bridge deck, beside the rigging. (01:47:25)
Continuity mistake: After Quint states that it's a 25-footer, he rushes below deck and when he comes up with the harpoon case, the gauges on the panel to his left are visible. When he answers the call from Amity Point light station, there is a new large black knob attached the corner of the panel, that was not there before. The paper mess at the top of the panel differs as well. (01:22:25)
Continuity mistake: In the scene where Hooper visits Brody's home, he brings two bottles of wine. Brody pours himself a large measure, and then gives his wife and Hooper some. If you look at the bottle a) it seems rather full for the amount he's just poured, and b) the level changes from shot to shot. Sometimes it's above the label, sometimes below.
Continuity mistake: At the end when Brody is up in the crow's nest of the Orca waiting for Bruce to get close enough for him to shoot the tank in Bruce's mouth, notice that the crow's nest is sinking much faster than Bruce is moving towards him. At these rates, the boat would have fully sunken before the shark got close enough.