Medieval Ships

IN my History of American Piracy Class my professor went over a little bit of Medieval ship building so I thought I would find some more info online...

http://www.medievalarchives.com/tag/friends-of-newport-medieval-ship

^ this is an archaeological site working on a medieval ship

and this is an image of a medieval ship from our lecture. Our professor commented on how medieval ships had square sails and still used manned oars as rudders...