Skipper Stu is the Grofflen Harbour dockmaster's diesel.
Skipper Stu, a US Navy veteran (who worked the Brooklyn Army Terminal), is the kindhearted leader of Grofflen Harbour, located at the midpoint of the Northern Crotoonian Coast (thus placing it between Celgreb Bay Harbour and Gridinia Bay Docks). Though he's kind hearted and fatherly to his Docker Crew (consisting of Haulers Hamish and Harry, and reach stacker Russ) and the other Crotoonians, he does come off as a bit of a windbag, wanting to keep things in perfect detail and ensure things are done pinpoint and on time (to the point where he says he's "never missed a deadline ever"). Unfortunately, this can make him loose his cool during particularity stressful situations. Despite this though, he's still a good leader to the Harbour Crew, and isn't afraid to pull his weight around the Docks.
Skipper Stu is not based on a specific prototype.
Skipper Stu is painted light sky blue and sky blue with red arrows with white outlines. His cab is also painted navy.