The scene when Jack Sparrow calls the Flying Dutchman "fishmates" and sings to them "I got a jar of dirt" was actually unscripted and it was improvised by Johnny Depp, most of the reactions of the rest of the characters are real.
The scene where Sparrow is hurled across a canyon and landing on his feet while tied to a pole, is amazingly not using CG nor any other sort of camera trickery, not even wires. A man was actually tied hands and feet to a pole and then, by the use of specially created rigs (along with a dose of scientific pre-calculations for acceleration, distance etc), physically catapulted over that junction, doing a somersault mid-ways in the air and landing perfect on his two feet - all in one take!
The dice game that Will Turner plays with Davy Jones is called Liar's Dice, a gambling game where each player has to make consecutively higher bids based upon how many of each die they claim are on the table (two threes, four fives, etc.), until a player is called a liar, in which case all the dice are shown and it's seen if the bid is correct. Normally a player only loses a die when caught in a lie and is not out of the game until he has lost all his dice.
Gore Verbinski initially rejected casting director Denise Chamian's suggestion to cast Naomie Harris as Tia Dalma, saying that she was too young for the role. Chamian insisted he give her a screen test. Finally, Harris's mother came with her for the audition; also serving as her dialect coach, since Dalma speaks in partial Jamaican accent.
It is stated in the DVD commentary that the scene where several people argue how to pronounce "kraken" was added due to an error by Kevin McNally. The word is said "Kray-ken", but when McNally first said the creature's name, he called it the "Kracken", and this caught on with the rest of the cast. The scene was added to show how the creature's name is actually said.
Rolling Stone Keith Richards was set to make a cameo appearance as the father of Captain Jack Sparrow, but Richards had to pull out of the project due to his commitment with The Rolling Stones world tour. Johnny Depp had previously said that his performance as Jack Sparrow was based on Richards.
A popular pirate punishment was "marooning". The pirate who was being punished was put on an island and left, sometimes for a few days, sometimes permanently. The "dead man's chest" is a small rocky island so called because the rocks reminded pirates of a ribcage. It has no water or shade and is so low that waves frequently wash over it. To be marooned on the "chest" was to be given a death sentence under the broiling Caribbean sun.
All of Davy Jones's crew were actors. They all wore dark gray motion-capture suits and before they could be filmed they had to be scanned in order for the computer to place the crew images over the top. Bill Nighy wore makeup around his eyes and mouth in case computer rendering failed to look realistic during extreme close ups (fortunately this was never needed).
When Mr. Gibbs is enlisting new recruits at the tavern, a bunch of men are pulling a man out of a well, and he slowly spits out water. This is a recreation of a scene in the Pirates of the Caribbean ride at the Walt Disney theme parks.
This marks famed special-effects house Industrial Light & Magic's first Oscar win since Forrest Gump (1994) 12 years previously. This is also the only "Pirates of the Caribbean" film to win the award in any of its nominated categories (as of 2010).
For the film's release, the Walt Disney Company redesigned the Pirates of the Caribbean rides in Walt Disney World and Disneyland to feature captain Jack Sparrow, Barbossa, and an appearance by the film's supernatural character Davy Jones as part of the attraction and premiered on the same day as the film.
The shack by the river as the crew go to see Tia Dalma is identical to the shack on the far side of the river across from the boarding dock of the Magic Kingdom's "Jungle Cruise" ride in Orlando, Florida.
When the sailors fight over the dress on the ship on which Elizabeth has stowed away, they talk about the ghost of a woman who was widowed before her wedding. This is similar to a plot point in the Disney Ride "The Haunted Mansion" at Walt Disney World.
The two sailors quarreling over Jack's hat on the boat which is then sunk by the Kraken are from Cyprus. The sailor on the left is Turkish-Cypriot while the other on the right is Greek-Cypriot and speaks the Greek-Cypriot dialect.
Throughout the movie, many references are made to the original Pirates of the Caribbean: The Curse of the Black Pearl (2003). These include the following: Cutler Beckett is corrected by Elizabeth and Will when he fails to refer to Jack Sparrow as "Captain" (Jack insisted on being called "Captain Jack Sparrow" in the first movie); Governor Swann breaks off an arm of a candlestick inside the dungeon (the same happened to Will in the Governor's house in the first movie); Governor Swann asks where the "dog with the keys" is; the dog is still holding the keys in the rowboat; Jack asks, "Why is the rum always gone?" (he asked Elizabeth the same twice in the first movie); Will gets slapped by a lady in Tortuga (Jack's being slapped by ladies he once mistreated was a running joke in the first film); Jack says "Hide the rum" when Elizabeth arrives (Elizabeth burned his rum in the first movie); a running gag plays on the fact that Jack the monkey is immortal (he stole one of the Cortez coins in the post-credits scene at the end of the first film).
The Kraken was difficult to animate as it had no real-life reference, until animation director Hal T. Hickel instructed the crew to watch King Kong vs. Godzilla (1962) which had a real octopus crawling over miniatures.
In an interview with CGSociety, Visual Effects Art Director Aaron McBride revealed that when he was given the task of doing photo-real illustrations of Davy Jones, there was talk that Christopher Walken would play the role.
Orlando Bloom and Bill Nighy have both appeared in adaptations of The Lord of the Rings. Bloom played Legolas in Peter Jackson's films, while Nighy was the voice of Sam Gamgee in the BBC Radio version.
Shooting in Dominica proved problematic. The government were completely unprepared for the scale of a Hollywood production, as while the 500-strong crew occupying around 90% of the roads on the island they had trouble moving around on the underdeveloped surfaces. The weather also alternated between torrential rainstorms and hot temperatures, the latter of which was made worse for the cast who had to wear period clothing.
Bill Nighy later revealed that Scottish sitcom Still Game (2002) influenced his choice of accent, stating: "I had to find an accent no one else had. Although Alex Norton is Scottish, mine was slightly different. We wanted something that was distinctive and authoritative...I have seen Still Game and I am a fan. The sort of extremity of the accent was inspired in that area."
Filming in Grand Bahama Island was a tumultuous period, starting with the fact that the tank had not actually been finished. The hurricane season caused many pauses in shooting, and Hurricane Wilma damaged many of the accessways and pumps, though no one was hurt nor were any of the ships destroyed.
To portray Jones on set, Bill Nighy wore a motion capture tracksuit that meant the animators at Industrial Light & Magic did not have to reshoot the scene in the studio without him or on the motion capture stage.
Captain Jack Sparrow referring to Elizabeth as "Lizzie" could be a reference to Keira Knightley's role as Elizabeth 'Lizzie' Bennett in Pride & Prejudice (2005) in the previous year. She was nominated for an Academy Award for this role.
Planning began in June 2004, and production was much larger than Pirates of the Caribbean: The Curse of the Black Pearl (2003). By November, the script was still unfinished as the writers didn't want Gore Verbinski and Jerry Bruckheimer to compromise what they had written, so Verbinski worked with James Ward Byrkit to storyboard major sequences without need of a script, while Elliott and Rossio wrote a "preparatory" script for the crew to use before they finished the script they were happy with. By January 2005, with rising costs and no script, Disney threatened to cancel the film, but changed their minds. The writers would accompany the crew on location, feeling that the lateness of their rewrites would improve the spontaneity of the cast's performances.
Gore Verbinski wanted to keep the Flying Dutchman crew realistic, rejecting a character with a turtle shell, and the animators watched various David Attenborough documentaries to study the movement of sea anemones and mussels.
The hierarchy among the Flying Dutchman crew is reflected by how mutated they were: newcomers have low level infections which resemble rosacea, while veterans have full-blown undersea creature attributes.
The MythBusters (2003) attempted to recreate the swinging the hanging cage segment but were unable to cause the cage to swing far enough to reach the "canyon" wall. They concluded that it was good cinema but impossible in real life.
According to the novelization for Pirates of the Caribbean: At World's End (2007), Elizabeth felt terribly guilty about leaving Jack to die at the hands of the Kraken at the climax. But she sensed he was proud of her pirate-like behavior.
Davy Jones had originally been designed with chin growths, before the designers made the move to full-blown tentacles. His skin incorporates the texture of a coffee-stained Styrofoam cup among other elements.
In the novelization for Pirates of the Caribbean: At World's End (2007), Elizabeth lost some respect for Norrington after he gave the heart of Davy Jones to Lord Cutler Beckett to regain his standing in the Navy, but he never stopped loving her, despite her love of the pirate's life.
For a dose of authenticity in the final twist at the end of the film, the actors were not told, prior to filming, that Geoffrey Rush would be appearing in the movie. They were told, before the scene was shot, that the person coming down the stairs would be Anamaria (Zoe Saldana) from Pirates of the Caribbean: The Curse of the Black Pearl (2003); the looks of surprise on their faces as Rush descends are genuine.
When Jack offers the monkey to Tia Dalma, she opens the cage, setting the monkey free. The monkey then runs off and starts playing with a pair of boots that are attached to a leg (presumably Captain Barbossa's).
When Jack Sparrow is at Tia Dalma's hut, there is a necklace on the table when Jack is stealing the ring. The picture on the necklace is the same image on the music box on Davy Jones' pipe organ, a hint to a major plot point in Pirates of the Caribbean: At World's End (2007).