pirates dead man effect

Special effects
The Flying Dutchman's crew were originally conceived by writers Ted Elliott and Terry Rossio as ghosts, but Gore Verbinski disliked this and designed them as physical creatures.[15] Their hierarchy is reflected by how mutated they were: newcomers had low level infections which resemble rosacea, while the most mutated had full-blown undersea creature attributes. Verbinski wanted to keep them 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.[16] All of the crew are computer-generated, with the exception of Stellan Skarsgård, who played "Bootstrap" Bill Turner. Initially his prosthetics would be augmented with CGI but that was abandoned.[17] Skarsgård spent four hours in the make-up chair and was dubbed "Bouillabaisse" on set.[18]
Captain Davy Jones himself had originally been designed with chin growths, before the designers made the move to full-blown tentacles;[19] the skin of the character is based on a blurred version of the texture of a coffee-stained Styrofoam cup. 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. Nighy wore make-up around his eyes and mouth to splice into the computer-generated shots, but the images of his eyes and mouth were not used. Nighy only wore a prosthetic once, with blue-colored tentacles for when Will Turner (Orlando Bloom) steals the key to the Dead Man's Chest from under his "beard" as he sleeps. To create the CG version of the character, the model was closely based on a full-body scan of Nighy, with Jones reflecting his high cheekbones. Animators studied every frame of Nighy's performance: the actor himself had blessed them by making his performance more quirky than expected, providing endless fun for them. His performance also meant new controls had to be stored. Finally, Jones' tentacles are mostly a simulation, though at times they were hand-animated when they act as limbs for the character.[20]
The Kraken was difficult to animate as it had no real-life reference, until animation director Hal Hickel instructed the crew to watch King Kong vs. Godzilla which had a real octopus crawling over miniatures.[21] On set, two pipes filled with 30,000 pounds of cement were used to crash and split the Edinburgh Trader: Completing the illusion are miniature masts and falling stuntmen shot on a bluescreen stage. The scene where the Kraken spits at Jack Sparrow does not use computer-generated spit: it was real gunge thrown at Johnny Depp.
source:Wikipedia