Continuity mistake: After Will rescues Elizabeth and brings her aboard the Interceptor, in the first shot from behind Elizabeth, Anamaria isn't holding her hat and the pirate behind Mr. Cotton is holding the tail of the parrot to keep it still. In the next couple of shots from the side, Anamaria is holding her hat because it's so windy. Just before Mr. Gibbs says, "Keep to the code," the close-up on Anamaria shows her hands down again, with no wind. In the next wide shot, Anamaria is holding her hat again due to the wind. (01:16:00)
Revealing mistake: In the close-up of Jack as he swims to get his gun, etc, his left sleeve is pushed up and it's very obvious that he's wearing something with short sleeves under his white shirt. This isn't part of his white shirt. He has nothing on under his white shirt at any other time. (The underwater close-up of Depp was filmed in a tank at Long Beach along with the close-ups rescuing Elizabeth earlier.) (01:34:50)
Continuity mistake: When Jack and Will are walking under water carrying the boat over their heads, Will steps into a wooden trap with a buoy line attached. The trap is made of wood sticks and in each of these shots the style of the wood sticks is different. In the first shot, Will's foot goes through the top, and is at one side of the rectangle trap and the buoy line is at the other side of the trap. In the next shot, Will looks down into the water at the wooden trap, his foot is in the center of a square wooden trap and the buoy line isn't seen in this shot. In the next wide shot, he's dragging the trap as he's walking under water, and his foot is at the same side as the attached buoy line, which is seen in this shot, on a rectangle trap. The trap is then tied to Dauntless' rudder, and again this trap is styled differently than the trap in the previous shots. This has nothing to do with the angle of the camera. (00:45:25)
Continuity mistake: Interceptor is side by side with Dauntless, in order to capture Jack and Will. Norrington boards Dauntless with three other men following him and in that close-up ON deck, Norrington says, "Search every cabin, every hull, down to the bilges." Yet, in the next shot, Norrington and those three men are actually seen just climbing up the gangplank to Dauntless. (00:46:55)
Continuity mistake: Barbossa rips the chain and medallion off Elizabeth's neck, puts it into her palm, then cuts her hand. He takes her hand in his and he turns hers over so it's palm down. The chain can be seen in the close-up and wide shot, dangling down between her fingers and the chain is NOT clasped shut. In the next close-up of the chain and medallion falling into the chest, the chain IS clasped shut. (01:11:55)
Revealing mistake: In the scene where Jack and Will have just taken the Interceptor and the Dauntless is coming about, the men on the row boat get caught in its path. A second after the men abandon ship, you see the boat get destroyed. If you look closely at the forward wake of the ship, the boat is too far away to be destroyed by the front of the ship. And since the boat initially goes down when it's struck, it can't be the keel of the ship, since that would send it up. (00:48:05)
Visible crew/equipment: Aboard the Interceptor, as Jack asks, "Can you sail under the command of a pirate...?" at the upper right corner of the screen, the corner of the crew's white reflector screen is perfectly visible in front of the boom. (00:50:15)
Visible crew/equipment: During the battle between the Interceptor and the Black Pearl, as Jack takes Elizabeth aside and asks her where the medallion is, on the top right corner is a film crew member's hand with a watch on it. (01:29:05)
Revealing mistake: During the sword fight in the blacksmith's shop, Will pulls a blade out of the fire. While fighting Jack, the heated blade sparks when their two swords clash. When Will blocks a hit from Jack, the impact is far BELOW the red/orange hot section of Will's sword, yet it sparks right at that spot. It also makes a kind of sound like electricity crackling. A heated blade would not make this noise, nor would it send out embers or sparks where it is not heated. Only the tip is heated, however the whole blade has an electrical current running through it, mentioned in another mistake. (00:24:15)
Continuity mistake: When Will and Jack are in the bar in Tortuga, Will stands with his back to the wall and on that wall is a shelf with a candle. The candle height changes and the candle drippings are very different in these shots too. Also, shots in the deleted scenes. (00:52:10)
Continuity mistake: When the medallion drops into the chest, and when Barbossa removes it, there is blood on both sides of the medallion. When Barbossa hits Elizabeth and she falls, the medallion falls near her. In this shot we do not see any blood on the medallion. Yet when Will rescues Elizabeth, she reaches for the medallion and it now has a very obvious blood stain on it. (01:12:20 - 01:13:35)
Revealing mistake: Before Interceptor's explosion, in the close-up it's very apparent that it's not the real Interceptor. Some examples are, no rigging at the stern-most mast, at the railing there are no belaying pins with or without all the lines hanging from them, there are no cleats with or without lines and at least two of the swiveling mounts at the stern for the swivel cannons aren't there. (01:30:40)
Deliberate mistake: Jack wears one pair of boots throughout the movie; however, the heel has at least two discernible heights, including the ones worn in the underwater close-up. One kind is worn by Tony Angelotti (Johnny Depp's stunt double) and the others are worn by Depp. When Jack steps onto the dock from the Jolly Mon and when he's balancing himself on Will's sword at the attempted hanging, he's wearing the higher heel boots. As Jack crawls across the broken mast chasing the monkey, and when he dives off the Pearl's plank, the lower heel boots are obvious. (01:34:40 - 02:06:30)
Deliberate mistake: After Will and Jack swing aboard Interceptor, Will cuts four lines from the belaying pins on Interceptor, that lead up to Dauntless and each line snaps back. As Interceptor pulls away though, we see other lines that are still connected to Dauntless, but then the shot cuts away. Because of a mishap during filming, it was the only shot Director, Gore Verbinski had of Interceptor pulling away from Dauntless. (00:47:05)
Continuity mistake: At the dock in Port Royal, in the close-up as Jack makes his escape from the Marines, he is standing on the beam as he throws his shackle chain over the rope. The ledge to his left, just under the rope, has a metal support that is flush with the wood's edge. In the next wide shot as Jack starts his descent down the rope, the ledge and its metal support are not the same as in the close-up, they are obviously very different. (00:20:10)
Continuity mistake: After her anchor is lowered, there's a front shot of Interceptor as it splashes wildly and a crewman that is dressed as Will is seen up on the port side of the rigging. After Elizabeth shouts, "Let go!" the crewman dressed as Will is up on the rigging, but now he's on the starboard side of the rigging. This is not a flipped shot, the sails are different in both shots too. (01:24:25)
Continuity mistake: At Jack's hanging, as the official says, "Impersonating an officer in the Spanish Royal Navy," in this far shot, we see the scaffolding and the Marines walking on wall behind. In the next shot, he says, "Impersonating a cleric of the church of England," and we still see the Marines. Then in the next shot, a close-up of Jack, we also see the Marines. These are successive shots, yet the Marines are NOT in positions of continuous walking. (02:05:05)
Revealing mistake: When Elizabeth falls down from the cliff, with her hat and scarf falling over her, you can see it is definitely not Keira Knightley, as the stuntperson's face is perfectly visible. (00:15:05)
Continuity mistake: After falling off the parapet, Elizabeth is under water, and we see a close-up of the medallion floating freely, causing a tremor in the water. When Jack gets her back on shore and rips open her corset, the medallion is now firmly tucked inside her dress - no way it could have just slipped in there given how insanely tight it was. (00:15:40)
Continuity mistake: Barbossa says, "Buried on an island of the dead what cannot be found, except for those who know where it is." In this shot only the objects in the center of the table slide down towards Elizabeth, including the two candelabras and her plate of food, having nothing to do with the object's weight. The objects that face Elizabeth on the table to her left and to her right don't move, only those on the moving center track. Also seen on DVD 2. (00:56:45)
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