Absolutely. But why build a boat at all when there are so many kayaks already produced by companies with a long history of successful designs?
For me, it was just something else to do, another experience from which to learn, with no hope or pretense of exceeding or even coming close to matching the designs already out there. I'd already built wonderful boats designed by Jay, Bjorn and Nick, as well as a modified version of one of Nick's designs. I had no shortage of boats in the "stable" -- and how many kayaks does one really need?
So as a starting point I studied and took lines from a production kayak I loved, compared it to other designs that I had paddled, tweaked it to reflect my own tastes, pursuits and experiences. What evolved was a unique boat with its own idiosyncrasies -- it does a few things it does better than other boats I have owned, and quite a few that would really disappoint but for the fact that they present new problems to understand and address.
The boat I'm currently working on will be a second iteration of that evolved design, lower volume, lighter, with less rocker and none of the cartoonish elements that had added more as a statement of style than function. And it will liklely be the last in this exploration, as I have no desire to perfect my design to the extent Jay, Nick, Bjorn, Rob and so many others who have taken up kayak design as a profession have done.
For me, it has just been something to do, and my next boat, if it is not a first for me strip-built canoe, is likely to be a gently-used fibreglass SKUK or Tiderace boat.