Called on to get a prince's bags to the ocean liner, Clément Mégé nicks the ticket and travels as the prince himself, indulging in all sorts of low-brow activities that the ship's captain and crew dismiss as the eccentricities of a great man.
The joke here, of course, is that none of these people have any understanding of how royalty actually behave, and so Mégé is indulged when he powders his boots or instructs a sailor in how to polish the brass. I did not find it particularly amusing, but given the audience for Gaumont's short comedies, the lower classes, this was probably viewed as quite funny, making mock of royalty and the middle class alike.