Utan Sonar

Shoujou's ship is a large vessel with an orangutan figurehead named Utan Sonar.

The main feature seems to be the giant trees that serve as masts. In addition, the sides of the ship have many doors with ladders that lead to the water to aid the Utan Divers in their work. The vessel also had one large paddle, on either side of the ship, that holds the special chambers where the Utan Divers actually work.

The phrase "mori no hito" (森のヒト) written on the main sail in English characters, under Shoujou's Jolly Roger, roughly translates as "humans of the forest". The pun here is that both "mori no miyako" (杜の都, literally translated as "town of the forest") and "mori no oku" (杜の奥, literally translated as "deep in the forest") only applies in the sense that Shoujou and the Utan Divers live within the "forest" made by the trees that make up the Utan Sonar's masts.