The Constellation:
The Constellation is the primary way that the current inhabitants of the Pocket traverse the multiverse. It was not originally owned/used/build by its current crew; some time ago, its Original Crew used the Constellation to navigate and chart the multiverse at the behest of their original civilization/universe. Remnants of the voyages of this crew can be found all over the multiverse, and are often considered extremely valuable by those who know what they have their hands (or hand-adjacent organs) on. It is believed that this Original Crew were the beings with the best understanding of the multiverse that have ever existed.
It is currently unknown what happened to the Constellation's Original Crew. Perhaps they returned to their original universe, wherever it may be; however, since they left the Constellation and the House inside the Pocket entirely unattended, it may indeed be the case that something catastrophic happened to the crew.
Appearance
The Constellation's appearance is largely consistent with a large wooden galley. The main differences one would see by examining the exterior are due to the flight mechanisms. Two large metal thrusters are attached to the stern, bolted into large metal plates which seem to be welded into the wooden exterior of the rest of the ship, despite the impossibility of such a construction. As well, the oarholes have been replaced with matte black circular panels, which allow the Constellation to fly and emit a slight purple glow when activated.
The deck of the ship is largely as one would expect from a galley, including a large ship's wheel for steering and two large sails, which are mostly aesthetic. There is also a crow's nest at the top of one of the masts. The lower decks are complete with sleeping quarters for the crew and a storage area.
Navigation:
An important room in the lower decks is the navigation room, where any universe hopping and trajectory calculation takes place. It is outfitted with large banks of servers for storing navigational data, although they had mostly been wiped clean by the time the Pocket Crew begins using the Constellation. There are several control panels used to navigate, and, as such, the navigation room is intended to be manned by several individuals, although the Pocket Crew only has one to two navigators at a time. This tends to result in a very rough ride when flying across the multiverse. It also results in a unique sound when entering or exiting a universe: a loud ripping sound, followed by a pop! and a loud bang.