Octopod

The Octopod is a  mobile undersea vehicle, and it is the Octonauts' home and headquarters. It consists of several interconnected areas. It is built to look like a Giant Octopus. It is also nuclear powered, as it can travel around the world indefinitely.

Main Areas
This large central areas contain most of the primary functions of the Octopod including HQ and the Launch bay. It also appears to house Peso's medical bay, Shellington's lab, Inkling's library, and Vegimals' Kitchen.

Side areas
There are four side areas. Two are subdivided into two bedrooms each; one split between Barnacles and Kwazii, and another split between Peso and Dashi. The remain two side areas house a garden and a games room respectively. The side modules are connected to the Main area by a series of flexible tubes through which the crew can slide down to get to the areas. Alternatively ladders are employed to get to areas which are higher up in the structure. The side areas can be retracted close to the main body when the Octopod is moving or in danger.

Steering
The Octopod can either be steered automatically by Dashi or manually by Barnacles. Manual steering is from a wheel house which emerges from the roof of the area and is reached by a lift, or in times of power cut, by Totem pole.

Trivia

 * The current Octopod is actually the second Octopod that was made.
 * The first and Original one crashed and was turned into an artificial reef said by Tweak in The Octopod Mystery.
 * It is modeled after the Pacific Octopus found in the same episode.