The Bark was a ship that had three masts, though the British used the term to basically mean a miscellaneous ship that didn't fit into any of the other categories for ship type. Such a ship could mean anything, from a raft to a high-speed racing catamaran, as long as the proposed model differed far enough from the original to be set in a different category from the derived medium. The Rise of Nations Bark model is that of a sail-powered catamaran.