One of the models of the Nautilus created by Harper Goff was a "squeezed" version which could be filmed with a standard lens and still look normal when projected in Cinemascope.
One of the models of the Nautilus used for filming was on display at Walt Disney World's EPCOT Center's attraction, "The Living Seas" until the display was remodeled.
Sections of the film were photographed on location in Jamaica and the Bahamas, by director Richard Fleischer and a crew of over 400 technicians.
Stage 3 and its tank were built at the Disney studio for the production of this film.
The actual undersea footage was shot in the Bahamas in the same location that was used for the silent 20,000 Leagues Under the Sea.
The climactic squid battle on the Nautilus was originally shot with a serene sunset and a calm sea. Director Richard Fleischer was troubled by the look of it because the cams and gears that operated the squid could easily be seen, making it look obviously fake. Walt Disney visited the set one day and Fleischer told him about the problem. Disney came up with the idea of having the squid battle take place during a fierce storm (another story is that it was actually screenwriter Earl Felton who came up with the idea). The scene was reshot that way and is considered by many to be the highlight of the film.
The interiors of the Nautilus were designed by Roland Hill, who subsequently designed the Disneyland "Sleeping Beauty's Castle."
The skiff was made of wood, painted to look like metal, and had to be weighted with sandbags to look heavy in the water. When towing it to the cannibals' island, the crew took the sandbags out to make their job easier, and they forgot to put them back in. When filming the scene where Ned and Conseil get in the boat to row away from the cannibals, Kirk Douglas expected the boat to be low in the water. He didn't lower the oars far enough to catch the water, and when he started to row, he fell on his back. Director Richard Fleischer thought the shot was so funny he left it in the film. When Ned starts to row, he clearly tips back, and his legs shoot up in the air.
The whole movie, except for the scenes where Ned Land and Conseil go ashore at New Guinea and meet the cannibals, and most of the underwater scenes with the divers, were filmed at the Disney Studio.
The world's first functional replica of Captain Nemo's diving helmet, built by Pat Regan of Vulcania Submarine, Hawaii, is on display in the Florida Keys History of Diving Museum in Islamorada, along with items from the film. He has also restored the one known surviving 'crown' or crewman diving helmet to operational condition.
This production was so large that Disney had to use facilities at other studios. This included Universal International (exterior sets redressed for the opening scenes) and 20th Century Fox (large exterior tank for the larger models).
This was Walt Disney's first feature using the new CinemaScope process, as well as one of the first productions outside of 20th Century-Fox use that anamorphic wide screen process. At the time, Bausch & Lomb had not been able to manufacture enough anamorphic lenses to meet the demand, so the Disney studios needed to lease the single available CinemaScope lens from 20th Century-Fox. This prevented multiple units from shooting at the same time, which not only contributed to the lengthy production schedule, but also--since Disney wanted the best possible value for the CinemaScope lens rental--explains the almost complete absence of close-up shots in the movie.
This was the first new full-length Disney film released by Buena Vista, Disney's new in-house distributor. Previous Disney films had been released by RKO, and re-releases of old Disney films were handled by Buena Vista from 1954 onwards.
This was the one of the first Disney films shown in a two-hour time slot on television (although very slightly edited). Most previous telecasts of Disney films, all shown on the anthology series Disneyland (aka "The Wonderful World of Color" and "The Wonderful World of Disney") had either featured the films edited down to fit a one-hour time slot or broken them up into two or more one-hour segments shown over a period of several weeks.
Until the late 1960s, many of the sets representing the interior of the Nautilus were used as an attraction at Disneyland. This included the chart room, the salon, with organ, and one of the observation windows. The squid from the movie was fastened over the observation window and was animated so that the beak would emerge, snap several times, and then retract. When the building housing the "20,000 Leagues" display was needed for a newer attraction, the sets were removed and many were destroyed.
When Disney executives saw some underwater scenes their photographers had filmed in the new VistaVision wide-screen format, they decided to make "20,000 Leagues Under the Sea" and incorporate some of the shots in it.
When the "Nautilus" rams a ship and we see how it sinks down through the water, some of the bubble-streams are animated to hide the wires that support the ship-model.