I couldn't miss the chance to practice my drawing!
After ending Saronia's civil war, head to Saronia Castle's courtyard and enter the eastern building. Speak to the engineers there and they will tell you they unearthed an ancient airship. The Nautilus will be restored and made available.
The Nautilus is mainly used to fly against strong winds. It also has the advantage over the Enterprise that it can land on the ground, saving the time and battles of traveling from the sea to one's destination. A disadvantage is that it cannot land on the sea, preventing the player from fighting sea-based monsters for the bestiary collection if they have not already been encountered.
The Nautilus is later enchanted to dive underwater. While in its submarine form, the party can explore the ocean floor and several dungeons that were previously inaccessible. It is still available for the party to use after the Invincible is obtained, and is faster than the Invincible, but lacks the healing, shop, and Fat Chocobo benefits.
Behind the scenes
In the English version remake it is stated that Cid Haze invented the Nautilus, while simultaneously claiming it to have been found in "Ancient ruins". The Japanese version posits that Cid resurrected the airship.
Nautilus is the fictional submarine captained by Nemo featured in Jules Verne's novels Twenty Thousand Leagues Under the Sea and The Mysterious Island. Verne named the Nautilus after Robert Fulton's real-life submarine Nautilus.The