I'm working on my interpretation of Brian Schultz's F1 (in link) using Tom Yost's design. Using GIMP (open source software similar to photoshop), I've come up with all the necessary numbers and copied them onto plywood for cross sections. The problem is that pointed out by Aaron H. where the diagram is somewhat ambiguous as far as the 'knuckle' or secondary chine on the gunwale. In a total worst case scenario, I'll be off by up to 3/4 of an inch. I've never even paddled on the ocean before, and am not going to have any idea as to whether or not the finished product is any good. My question is: how could being off by 1/2" in this area impact the performance? Should I worry about it a lot or will it not be too big of a deal? I'm about ready to cut, and the entire point of this build was to do something quickly, so I'm sort of anxious to just jump right in. On the other hand, I can't throw away over a hundred dollars....

If anyone is able to help interpret that diagram, that would be awesome as well. Without further clarification, I'm going to assume that on the cross sectional view (the one with the numbered sections), the knuckle line marks the outside of the center of the knuckle. It seems closes to the actual measurments when compared against his dimensions. Some things aren't quite lining up - he says the gunwales are 2.5", but in the cross sectional view, the line segment from the top of the gunwale to the knuckle is 2.33" according to my method of scaling which appears to have worked beautifully with everything else. I considered that the discrepancy was a result of the line being from the top corner of the gunwale to the top corner of the knuckle, but that distance would actually be ~2.03". Go figure.

The real point is, does it matter?

Image hosted on Brian's site: http://www.capefalconkayak.com/f1surveyweb.jpg