If you really want to do it
Posted by: pblanc
on Nov-01-12 1:50 PM (EST)
and you have a sizable flat surface like a patio, deck, or driveway you can set the boat on that. It seems to make most sense measuring the LWL at the same waterline that the BWL is measured. I seem to recall from somewhere that the BWL for the Argosy given by Wenonah is at the 3" waterline, but it could be 4" or something in between.
If you want to measure the LWL at the 3" waterline, get a little rectangle of scrap wood 3" long on one side that has a true right angle, or make one. Set the canoe on the flat surface and butt the piece of wood up to the stem of the boat with the wood aligned with the keel line and mark the position on the flat surface. That will give you the position immediately below the 3" waterline.
Then use a plumb line or a level touching the very tip of the deck plate and mark that position on the surface. Measure between the marks and get the "deadwood" measurement for that end of the boat. Then repeat for the other end. Add the two and subtract the total from the LOA.
Might not work precisely for a very short, very asymmetrically rockered canoe, but it should be close enough for government work for the Argosy.