Plot hole: There are six metal bars mounted around the circumference of the water wheel's axle. In the wheel's interior, when Jack frees himself he lands on his feet, begins to run and promptly hits his head on one of those axle bars, then falls out. Moments later, when Jack returns and runs in the wheel, he is shorter (way more than a foot) than all six spinning axle bars, which would make that previous shot impossible, however humorous it is. (01:52:40 - 01:53:55)
Continuity mistake: When the water wheel begins to roll, with Norrington and Will atop and then snatches up Jack, its blades (buckets on the outside rim) and two sides of the axle face a specific direction as it gains speed. Now compare the following two shots, as the water wheel rolls away from the camera: When the wheel rolls, just as Jack falls out, after hitting his head on the bar. Then later on the beach, as Elizabeth watches, just as the wheel rolls and falls over in the close-up, the wheel is actually rolling in the opposite direction - just note its blades. Also note the bizarre change of its axle's wide and narrow sides. (01:52:40 - 01:56:50)
Continuity mistake: When the huge water wheel rolls to the beach and falls on its side, it falls with the broken, wide, wood side of the axle facing up. However, as Will and Norrington climb out, inexplicably it's the slim side of the water wheel's axle that is now facing up. But in a following shot, it is the other way round again.
Other mistake: The rope is wound round Jack's body and the pole at his back numerous times. When Shishka-Jack falls, the pole gets jammed between the cliffs, but the pole does not break and the rope does not tear. The rope that goes round the pole numerous times simply disappears, leaving the rope intact around only Jack's body in order for Jack to twirl and unravel as he falls.
Continuity mistake: During the Kraken attack on the Pearl, Jack sneaks away in the long boat at the Pearl's port side. However, when Elizabeth walks over to the deck rail, sees Jack and says, "Oh, you coward!" she is actually standing at the Pearl's starboard side, and it would be quite impossible to see Jack. Take note of the rail rigging and mast.
Continuity mistake: After Jack opens the lid of the large chest, there is a close-up of the filled interior, which lies nearly a foot below the top edge of the large chest, with the smaller inner chest well hidden below. However, in the next shot the lid of the smaller inner chest is way up higher, actually level with the top edge of the large chest - before Jack lifts it.
Deliberate mistake: When Will is bound and brought before "Chief" Jack, Will says, "The compass!" and there is a close-up of the compass, as it hangs to the right of the long striped cloth. However, in all other shots the compass hangs to the left of the red and white striped cloth. This is a flipped shot - note the large buckles.
Continuity mistake: After Jack is hung up over the kindling, to be "roasted and eaten", a cannibal carries a torch across the bridge and shouts. In the cannibal's close-up, the painted black/white sticks pierce his left ear, whereas in the previous and following shots the sticks actually pierce his right ear. The close-up is a flipped shot for continuity of face position. (Mostly visible on widescreen version). (00:37:50)
Continuity mistake: When the cannibal walks across the bridge and sees some prisoners fall to their death and the others escaping, there is a long stick, which has a black design on it, threaded through his lip. When he arrives back at Jack's roasting, the stick's design is very different. (00:36:10)
Continuity mistake: Aboard the Pearl, after Will orders the rum to be loaded, and Gibbs responds, "Aye, the rum too," the cloth round Gibbs's neck has the loop to his right, but in previous and following shots it's actually "tied" round his neck the opposite way, with the loop to his left. (02:00:00)
Continuity mistake: After the Flying Dutchman's attack on the Pearl, when the Kraken attacks the Pearl, one of its tentacles comes through the captain's stateroom stern windows, which has considerable damage - notably the left window and part of the wall are completely gone. When Gibbs says, "Abandon ship or abandon hope," the stern windows are actually more intact - especially the left window/wall.