I haven't done much with this project in months. But now that I don't have to build a fire in a dark shop I'm back at it.
How do you design a boat from scratch?
Build a 1/12th scale model and fiddle with it.
Make some side panels. The models helped to estimate how much to dish out the chine edge.
Mount the side panels on adjustable ribs with temporary stem and transom.
Play with widths and side angles until it looks right.
Now, at this stage I'm happy with the shape but it's far too crooked to build. So now I'll measure things up and write down temporary rib angles and dimensions, and replace them with 3/4" sub flooring plywood, with vertical centerlines drawn on the new plywood (but still temporary) ribs.
Then I can straighten it up from front to back. Then drape it with 4mil Visqueen and cover the form or plug with Plascore. Fiberglass it on the outside. Take it off the mold. Straighten up one more time and fiberglass the inside.
Build the deck. Etc.
The following plug will need a few more side-to-side spacers at the transom end--after straightening and before covering with Visqueen and Plascore. It's important to remember the Algonquins made birch bark canoes............that were good boats.
What counts most is getting the right overall shape. The right widths side flare and the right rocker profile. And to remember wider is better. The original Oregon boats were 48" inches wide because plywood was 48" inches. This one will be 64" inches wide at on the bottom at dead middle. Made from 18' foot side panels it will end up about 17' feet long end to end.
The 17x54 boats most people make (for a 17' footer) is the original McKenzie 15x48 boat scaled up proportionately. But wider is better. 48" was form follows material convenience, not form follows function, as so many have claimed.