I also thought it curious there was no provision for a seat in the kidyak plans. My seven-year old and I built a smaller version of the "slat" seat I built for my Mill Creek, and it worked fine. This winter I'm going to move it forward, since the boat rode a little low in the back (stern, I guess).

I also made the cockpit much smaller than the plans called for. His legs aren't completely under the deck, but it doesn't look like a canoe, either.

A thought - my son and three year old daughter loved painting it. It was too much fun, and it gave them a great sense of "I helped build it." If he lives close enough, you might want to give it to him unfinished, then ask for his help in choosing and applying the paint.