Continuity mistake: While underwater, as Jack removes Elizabeth's water-logged dress, his left hand and arm are visibly clean, as well as when he has her on his shoulder at the dock. Then while kneeling over her on the dock, Jack's left hand and arm are extremely grimy and dirty. Yet when Norrington grabs Jack to bring him to Gillette, and while Jack holds Elizabeth hostage, his left hand and arm are clean once again. (00:16:10 - 00:18:40)
Continuity mistake: At Jack's hanging, after Will sees Mr Cotton's parrot he walks over to Norrington, Elizabeth and her father. In the wide shot, when he says, "Governor Swann," the woman in the grey hat, white shawl, and floral pattern dress, who stands behind him to his right, in the next close-ups, is not in this wide shot. (02:05:40)
Continuity mistake: Jack removes Anamaria's hat, in the front shot her hair falls down, and in the next back shot, her hair falls again. Also, the striped scarf around her forehead changes in the arrangement of the stripes in different shots. In the front shots the yellow stripe is on top, but in the side shots the grey stripe is on top. (01:02:05)
Continuity mistake: Aboard Interceptor, Will cuts the lines leading to Dauntless with his axe and Interceptor pulls away. As they pull away, the first gangplank falls, knocks into the swivel cannon on the rail of Interceptor, forcing it to now point up. Jack and Will are busy stealing Interceptor. When Jack yells out, "Thank you, Commodore!" the cannon is turned straight around again. The first shot was part of the mishap during filming, as noted in another mistake. (00:47:05)
Continuity mistake: As Elizabeth says, "Lower the anchor on the right side," Mr. Gibbs' right white collar is under the leather strap buckled correctly and Will's neck scarf is crooked. In the next shot, when Elizabeth says, "On the starboard side," Mr. Gibbs' leather strap is not buckled properly, his right white collar is over the strap and Will's neck scarf is straight. When Mr. Gibbs says, "Daft like Jack," his white collar is under the strap again and one end of Mr. Gibbs' neck string is much longer than the other end. Also, Will's right white shirt collar is over his vest. Yet when Mr. Gibbs says, "Do it, you gobs..." the ends of Mr. Gibbs' neck string are even and Will's right white collar is under his vest. (01:24:00)
Continuity mistake: After escaping, while Jack is swinging quickly about on the rope, in the first wide shot, he hangs low on the rope and the excess rope reaches his knees. When Jack yells, "Whoa!" he is higher on the rope and yet the excess rope still just reaches his knees. Then when Norrington shouts, "Open fire!" still higher on the rope, the excess rope is now way below his feet. (00:19:50)
Continuity mistake: Aboard Interceptor, the boom slams into Will and takes him out over the water. In the close-up shot of Will hanging there, the rope lines that are between Will's arms on the boom are not in the close-up shot of the boom, before it hit Will. Just the line to his left, can be seen in the boom shot. (00:49:35)
Continuity mistake: After Elizabeth falls off the ramparts, the first shot is of an unconscious Elizabeth under water, and her right shoe is not on, at the heel. In the next two shots, the shoe is perfectly on. (00:15:15)
Continuity mistake: As the boom slams into Will, there's no pile of rope lying at the stern, only one line. In the next shot, Jack reaches down to pick up Will's sword and now there's a pile of rope lying on deck. When Jack swings the boom back and Will drops on deck, there's no pile of rope on deck again. This doesn't refer to the rigging lines attached to the boom. (00:49:35)
Continuity mistake: In the blacksmith shop, Will grabs a sword out of the fire and fights Jack with a red-hot blade. Jack flings the end of his handcuff chain around Will's sword which IS still glowing red, grabs the blade, and yanks it out of Will's hand. The blade is no longer glowing red as it flies out of Will's hand and through the air. The blade could NOT have cooled that quickly. (00:24:25)
Continuity mistake: Jack walks past the dock master, behind Jack the desk is on a wagon and the handle is leaning on the left side of the desk. Also the feather quill on the desk is leaning towards the back of the desk. When Jack walks away and takes the sack of money, the handle of the wagon isn't leaning on the desk and the feather quill on the desk is leaning forward towards the front of the desk. (00:10:10)
Continuity mistake: The hangman hits the rope on the wood beam, but the blade doesn't embed itself in the wood, the way it's in the subsequent shots. After Norrington looks up to see the hangman's about to fall on him, in the next front shot, Will pushes the hangman toward the crowd and he starts to raise his arms. Here the axe is embedded perfectly perpendicular in the wood beam. As Jack and Will run with the rope, the axe is seen behind them and it's not at all embedded in the wood as in the earlier shot. This is not because of the angle of the camera. (02:06:50)
Continuity mistake: During the final duel between Barbossa and Jack, Will runs to the Aztec chest. Jack tosses the medallion to Will, and as Barbossa turns his head, we see the white shirt collar. Barbossa pulls out his gun and aims it towards Elizabeth. In Barbossa's front shot, there is barely white collar showing, but in the next side shot, the white collar shows on both sides. Jack shoots Barbossa, and in the front shot, there's barely white collar showing. When he turns to look at Will, and when he turns back towards Jack, the white collar shows again. (02:00:40)
Continuity mistake: As the Interceptor sails away from the Dauntless, Norrington, aboard Dauntless, is standing in front of the wheel looking out towards the Interceptor. In the next shots, the Dauntless is colliding with the boat and in the background the Interceptor can be seen going in the opposite direction. Then back on Dauntless, Norrington is still looking towards the Interceptor in the same direction as before, however wrong that is, and acknowledges the comment, "That's got to be the best pirate I've ever seen." (00:47:45)
Continuity mistake: Pintel and Ragetti walk into the stateroom, Pintel carries the folded dress for Elizabeth in his arms. She walks over to them. In the next shot, the folded dress is now folded differently in Pintel's arms. Also, when they tell her she'll be dining with the Captain, Ragetti's collar is under the strap on his shoulder. After she answers them, in their next close-up, his collar is straight and over the strap. (00:54:15)
Continuity mistake: At the Fort, the two columns of soldiers separate and Norrington walks into view. It's shouted, "Right about face," and the soldier behind Norrington on his left has his black bag to his side. When "present arms" is shouted, the soldier's black bag is in front. Also, Governor Swann, in the front wide shot, is standing on the second step from the bottom. In the next close-up, he's standing on a step further up - the soldier to his left in the previous shot was standing on the same step as him. (00:11:15)
Continuity mistake: After Elizabeth whacks Jacoby and tells him to try wearing a corset, she helps Will to his feet. In the close-up of Will smiling and looking at her, his hair is noticeably wet and very stringy. However when Elizabeth asks, "Whose side is Jack on?" Will's hair is no longer wet. (01:59:50)
Continuity mistake: At Jack's hanging, Will draws his sword and shouts, "Move!" The next shot is of the crowd in front of him parting and there is a clear view of the hanging scaffolding. Then in Will's next shot, we see the same crowd from the front, parting again as Will throws the sword into the falling trap door. (02:06:15)
Continuity mistake: Jack escapes the brig of the Black Pearl, goes up on deck and grabs the line from another and says, "Thanks very much." This shot's flipped. In the next wide shot of Jack (Tony Angelotti), he grabs the line again and swings across. The flipping was done in order to keep the Interceptor on the left of the screen and the Black Pearl on the right of the screen during the fight sequence. (01:28:15)
Continuity mistake: When the Interceptor drops its anchor on the right side to surprise the Black Pearl, Barbossa turns to the crew and yells, "Hard to port. Rack the starboard oars." When he says this line, his teeth are either normal, or not nearly as gross as they are in the rest of the movie. [Fixed on Blu-Ray]. (01:24:40)
Answer: The curse needs the blood of everybody who took a coin from the chest. All the other pirates have already contributed so, as the movie opens, the only blood needed is Will's, substituting for his father. During the finale of the movie, Jack takes a coin from the chest, adding himself to the curse, so his blood is now required as well as Will's.
Tailkinker ★
But I didn't see any blood on the coins, and none of the pirates cut themselves, even before Will became part of the mix.
Yes, the other pirates did cut themselves before Will came into it, off-screen. The lack of blood on the coins can simply be explained as most of it dripping to the bottom of the chest, it being washed away by storms blown into the cave, or by the fact that they didn't drop that much blood on it in the first place.
When they had Elizabeth they believed she was Bill Turner's daughter, but they all thought the curse had failed, none of them had cut themselves so it makes zero sense.
They had been collecting back the coins for years. During that time they repaid their own blood. All they needed was the last coin and the blood of Bill Turner to break the spell.
lionhead