Billy Gilbert was great!

Yeah the sound of his voice as the captain is magical! Double take/slow burns were funny too.

When he pretends to abuse his crew in order to scare the kids, Gilbert calls Harry Bernard and another crew member over for more verball mistreatment. The dialog goes like this:
GILBERT: What are you two doing over there?
BERNARD:We don't know, Captain.

Leonard Maltin called this one of the most memorable bits of dialog in the history of the movies.