Pirate Kilts?

[Woodsheal]

The short, wide baggy trousers were called "petticoat breeches" or "slops." They were worn over knee-brecches to protect them from tar and other shipboard grime. Canvas aprons - not really kilts - were worn for the same purpose. Longer, less-wide, more typical looking trousers of sea-cloth were also worn instead of knee-breeches:

http://www.gentlemenoffortune.com/basic_kit.htm