Submersion

Submersion is the essential condition of the Nautilus, the state that defines its existence and enables Captain Nemo's entire underwater world. It is not merely a navigational technique but the defining principle of the vessel's life, the mechanism by which it severs ties with the surface world and gains access to realms no human had ever seen. The Nautilus's ability to submerge is the foundation of its independence, its power, and its secrets.

Mechanism and Control

The Nautilus achieves submersion through a sophisticated system of ballast tanks and slanting fins. Captain Nemo explains that when the vessel lies on the waves, one-tenth of it emerges above water. By filling ballast tanks equal in capacity to that one-tenth, the boat displaces its full volume and becomes completely submerged. For deeper dives, the captain uses supplementary ballast tanks capable of shipping 100 metric tons of water, allowing descent to considerable depths. To rise again, the water is expelled. For vertical movement, the Nautilus uses two flexible fins attached to its sides at its center of flotation; when these fins slant, the vessel sinks or rises on a diagonal under its propeller's thrust. For a swift return to the surface, the propeller is thrown in gear, and the water's pressure makes the Nautilus rise vertically, like an air balloon. The helmsman, stationed behind windows of biconvex glass in a pilothouse, follows the course given by Captain Nemo, aided by a powerful electric reflector that lights up the sea for half a mile.

Power and Independence

Submersion is powered by electricity, which Captain Nemo calls "a powerful, obedient, swift, and effortless force" that reigns supreme aboard his vessel. It lights, warms, and is the soul of his mechanical equipment. The electricity is generated from sodium extracted from salt water, using coal from underwater mines. This system frees the Nautilus from any dependence on the shore. The captain declares that he owes everything to the ocean; it generates electricity, and electricity gives the Nautilus heat, light, motion, and life itself. The vessel's pumps, driven by this nearly infinite power, can overcome the immense pressure of the deep, allowing it to reach depths of 16,000 meters, where its plating tolerates 1,600 atmospheres of pressure.

The Experience of Submersion

For those aboard, submersion creates a world of constant wonder and profound isolation. Professor Aronnax describes the experience as entering a "new element," where the sea is visible through the lounge windows, brightly lit by the ship's electric outpourings. The transparency of salt water allows them to see for a mile radius, and the electric glow generates "liquid light." This state also provides absolute tranquility; Captain Nemo notes that just a few meters beneath the waves, the Nautilus finds absolute calm, free from storms and the constant feeling of an underlying chasm that plagues surface ships. The daily rhythm of submersion includes periodic returns to the surface to renew the air supply, a process the captain compares to a cetacean breathing. This cycle of descent and ascent structures the voyage, punctuating the continuous exploration of the deep.

Submersion as a Principle of Existence

Submersion is more than a technical feat; it is the physical embodiment of Captain Nemo's philosophy. He tells Aronnax that the sea does not belong to tyrants; on its surface they can exercise their iniquitous claims, but thirty feet below sea level, their dominion ceases. Submersion is the means by which Nemo achieves his freedom, independence, and separation from a hated humanity. The Nautilus's motto, "Mobilis in Mobili" ("Moving within the moving element"), captures this state perfectly: the vessel is in constant motion within the ever-moving sea, a self-contained world that is both part of and utterly separate from the ocean. This state is also the vessel's ultimate defense, as seen when it submerges to escape the Abraham Lincoln or when it uses its ability to dive under the Ice Bank to reach the South Pole. Submersion is the condition that makes the Nautilus invulnerable, allowing it to navigate the most dangerous waters and to execute Captain Nemo's will, whether for exploration or for vengeance.