The Flounder is Cap'n Turbot's boat.
In early Season 1, the Flounder is gray with a yellow, white, and purple hull. The top of the boat is red. From "Pups and the Beanstalk" through "Pups and the Lighthouse Boogie," the gray sections are replaced with yellow and purple portions. This color scheme stays with the boat for the rest of the series. From the second season onward, the Flounder is much larger in size and has many portholes along the hull, in addition to a red crane on the end that holds the diving bell. The Flounder contains a flight of gray stairs and a cargo hold. Inside the boat are many crates, a wooden table, several chairs, a corded wall telephone and a lamp (all of which can be seen in "Pups Save the Penguins"). In several earlier episodes, a storage area appears in place of the staircase.
The Flounder appears in the theme song of every episode. It can also be seen in the following episodes: