Nautilus (Verne) from seawater) is the craft's primary power source for propulsion and other services. "Nautilus" is double-hulled, and is further separated into water-tight compartments. Its top speed is . Its displacement is submerged. In Captain Nemo's own words: "Nautilus" uses floodable tanks in order to adjust buoyancy and so control its depth. The pumps that evacuate these tanks of water are so powerful that they produce large jets of water when the vessel emerges rapidly from the surface of the water. This leads many early observers of "Nautilus" to believe that the vessel is some species of whale, or perhaps a
Twenty Thousand Leagues Under the Sea as an inhabitant of British Colonial India, "is an inhabitant of an oppressed country". Verne took the name "Nautilus" from one of the earliest successful submarines, built in 1800 by Robert Fulton, who later invented the first commercially successful steamboat. Fulton's submarine was named after the paper nautilus because it had a sail. Three years before writing his novel, Jules Verne also studied a model of the newly developed French Navy submarine "Plongeur" at the 1867 Exposition Universelle, which inspired him for his definition of the "Nautilus". The breathing apparatus used by "Nautilus" divers is depicted as an untethered version