I have completed a first draft of the Great Auk forms with a rounded deck and am planning a second. For my first effort, I drew what my CAD program (TurboCAD Designer 3.0)called a bezier curve from the sheer point, through each point to the peak, and back down to the sheer. The bezier curve tries to make a smooth curve through or near the points selected. The result looks pretty good, at least as far as each form is concerned, but I lost a bit more leg room than I hoped.

For my second effort, I plan to force the curve through a point that some % (TBD) above the sheer, of the distance between the sheer and the current peak. This is more like what is recommended on page 186 of Nick's book, first col near the bottom.

I'm a little nervous about the modification too. I plan to verify that the changes are OK by printing out the forms and eye-balling the result. My current plan is to build the kayak with the designed hull and a modified deck. At worst, I'll have a good hull with a funny looking deck.