Inspired by the magnificent Jules Verne novel, the classic 1954 live-action Disney film, and Imagineering's previous explorations of Verne's source material with the eponymous submarine attraction at the Magic Kingdom and Les Mystères du Nautilus at Disneyland Paris, this attraction takes guests far below the ocean waves. This backstory comes from the Tokyo DisneySea Press Kit, as provided by LaughingPlace.com.
20,000 Leagues Under the Sea Backstory
The time is the 1870s. On an uncharted island somewhere in the South Pacific, a giant volcano rises up from the ocean depths. This is Mysterious Island, the secret base of operations for the enigmatic genius, Captain Nemo. It is here that he is engaged in experiments and research intent upon unlocking the secrets of the oceans and uncovering the hidden forces of nature deep beneath the earth's surface.
Inside the caldera, a crater formed at the base of the volcano, a large body of water provides secret access to the ocean beyond. Suspended above the water is a small submersible vessel, the Neptune. This is Captain Nemo's personal submarine boat, capable of taking him to underwater locales not accessible by his larger submarine, the Nautilus.
In an unprecedented decision, Captain Nemo has invited the world's scientific community to come to Mysterious Island and share in his discoveries of the countless marvels and mysteries of the ocean's depths. He has announced that his special guests will be permitted to board one of his fleet of submersibles, similar to the Neptune, and join his crew as observers to assist in his research and to share the ocean's majesty.
To board their vessel, guests descend a spiral ramp and enter a volcanic rock cavern that leads first to Captain Nemo's Private Study and Control Station. Discovering that Captain Nemo is working in another part of the facility, they are able to walk through these private quarters and observe Nemo's various notes, maps and research materials related to his studies of the sea and his efforts to develop the ocean floor for fanning. It is here too that they are introduced to the Aquaphone. Nemo's amazing wireless communications invention, which allows him to monitor activities throughout Mysterious Island and to broadcast information to his fleet of research vessels under the sea.
Moving along, they enter the Dive Hatch Area where they observe that Nemo and his crew are able to don diving suits and enter the ocean directly through a special pressure hatch. It is clear from the missing dive suits in the storage area, and from the seawater and kelp around the hatch, that divers must have recently used the hatch and that their dive is still in progress.
Soon the guests enter the Submarine Docking Port, a rock cavern that has been reinforced by large metal riveted plates. The submersibles are suspended from an overhead conveyor system for loading. They arc attached by large metal hooks that release the vessels into the water. Guests board the six-person submersibles and the conveyor moves them to the ocean's edge to be dropped into the water and begin their dive.
Upon release, Captain Nemo can be heard over the Aquaphone in the vessel. He broadcasts along the way and provides information to the intrepid voyagers about the sites they see. In their first view after diving to the ocean floor, they observe the beauty of the ocean reef around the perimeter of Mysterious Island. Then they enter one of the many undersea fields where Nemo is harvesting the limitless bounty of the ocean and continuing to develop and refine his Aquafarming operations.
Nemo reminds his guests that the ocean is a vast and wondrous place, but that it is not a domain that can be controlled by man - that man is merely a visitor in the sea. As evidence, guests next encounter a graveyard of lost ships. As they float through the Ship Graveyard, in and out of the wrecks of sunken ships from every era, they observe that all the power and riches the people who piloted these vessels might have possessed or sought, were only destined to become so much junk at the bottom of the sea-a playground for the denizens of the deep.
But there is little time to reflect on the irony of man's quest for fame and fortune. An unexpected encounter with a sea creature of mammoth proportions leads guests on a life-or-death adventure beyond imagination. Sinking to a depth far deeper than ever thought possible, the guests soon discover secrets of the deep that even Nemo himself never dared imagine possible.