On Sun, 08 Feb 2009 19:01:50 -0600, Jim Willemin
wrote:

Thanks to all who responded. I got a little confused thinking of open
boats, but then I looked up 'floor' and discovered that it is 'that part of
the bottom of a vessel on each side of the keelson which is most nearly
horizontal'.

Close but not quite. The actual term in wooden boat construction is
"floor timbers" which are transverse structural members, generally
horizontal, and laid just above the keel.

A picture is worth a thousand words:

http://www.thewoodenboatschool.com/b...estoration.jpg