: The kicker is that i actually drafted them in CAD, printed them out
: full size, mounted them to the ply with spraymount, and still
: screwed it up...

: John R

I had less than an inch on mine - 3/4". But I have 3/4"plywood for my cross sections. So I was able to make the cut outs a little wider. I used 3/4 inch ply because the day I made my cross sections was Labor Day and none of the stores were open, and that's all that I had in my basement. I'm no expert on performance, but I think the 15R is a nice design. A little tippy at first, like most sea kayaks, but it really tracks well and can make headway in choppy water, at least better than a plastic kayak can.