We did three versions: Tik Tak (8' long, 32"- 38" wide, 2 sheets of plywood) Tik Tak Ten-ish (116" long, 28" wide, 2 sheets of plywood), and the Tik Tak Too (12' long, whatever width you want up to 38", 3 sheets of ply)

All of them work great.

http://toledocommunityboathouse.com/plans/150318_tiktakten/tiktak.pdf