It might be easier to build the Grebe from plywood, and then measure it and create a table of offsets than to convert the figures used for laying out the panels into a table of offsets that you could work from.

Conceivably you could find the middle of the panel markings and construct on paper a polygon which would have sides equal in length to the width of the corresponding panels at that point on the boat. The overall width of the polygon would be the beam. Other than that one frame layout, though, there just is not enough information in those panel layout tables to work with.

Even if you were able to draw polygons from data at other points along the panels, without a complete boat nearby to check things against you would have to guess at the overall width and height of each frame, and then you would have to guess at where to mount these frames so that you obtained the same rocker and deadrise as the original design.

You might write to Squeedunk and ask if the offsets are available. Then you would make frames at roughly 2 foot intervals and bend your chines around these.

Or, you could look at clark craft's plans for short S-O-F kayaks (www.clarkcraft.com) they have a 13 foot "Sea Scout", and a 14 foot "racing" kayak which might interest you. I've been toying for years with their plans for a folding 13 foot kayak, and built a non-folding frame from the plans with the intention of using it as a form for sewing skins for the eventual folders I would build, but I never got that far. The frame is simple and fast to make if you don't mess with trying to make the brass brackets and connectors for making the boat fold.

If you go with a commercial plan which uses plywood frames, stack three sheets of plywood and cut three identical forms at the same time. You'll have enough for everyone to use that way.

PGJ