Dag,
I had meant to comment on your suggestion of using a kayak instead of canoe as a donor for making a sidecar. It would be more aerodynamic and narrower. The width of a canoe is what concerns me without being able to take measurements until I get home. A longer canoe, say a 17 or 19 footer would have a longer taper, so would have less beam at the cutoff point for making it into a sidecar stubby, but it still might be too wide. On the other hand I would think that the aluminum would be lighter than the glass or plastic of a kayak. And there is also my being enamored with canoes. I first started using a 17 footer by myself when I was six years old. I had to sit or kneel turned around in the bow and had a pile of rocks in the other end to keep it from blowing all over in gusts of wind. I recall some tearful struggles which I lost and found myself at the far end of the lake with a long way home. Then my father let me use a boat with a 2 1/2 hsp motor... oh yeah. Anyway, me an canoes go back a long way. I also figure that my local town being kind of a canoe town due to all of the outfitters for the B.W.C.A. it is appropriate and will be appreciated more than a kayak which some of the locals view as being kind of citified and hoity toity. And there's the added factor that with so many canoes the chances of finding a mangled one is pretty good. But a kayak would be a real good choice I would think.
SB