ight shape for the supports is a "joggle stick". There is a good article in Wooden Boat magazine that explains how to make and use one. It's basically just a thin, pointed board having numbered jagged edges so as to allow its position against a reference sheet to be reproduced accurately. (I made mine out of some scrap 6 mm plywood). Once the tip is placed against a series of reference points on the boat, and the outline of the joggle stick drawn, the reference points can be reproduced on the wood stock, allowing a smooth curve to be drawn.If I could do this part over again, I probably would have fitted the floor supports that attach to the
plywood frames before fitting the hull panels, which would have been much easier (just cut them flush with the frames). Then only 4 additional supports would have had to be fitted. As it was, even with the joggle stick, there was still a fair amount of trial-and-error to get a decent fit. Rather than try to get it perfect, I ended up filling in some gaps with thickened epoxy.The supports that butt against the frames were easy to trim off to the correct height. For the ones in between, I used a length of kite string and cut two reference gaps to allow the top of the support to be defined.
Finally, I glued them all in (and screwed them from the inside of the frames), using the kite string to keep them in place while the epoxy cured.
