I am in the process of building a kayak/sampan/skinny boat. It is a long draw out story, which is available in full at a blog. Rather than repeat it here, I'll give you the link:
The synopsis is that I volunteered to recycle the scrap wood at a local boat show. Part of the boat is a contest to build a 12' skiff. A lot of scrap wood is generated that had previously gone into a dumpster to head to the landfill. In addition to being environmentally responsible, keeping good wood out of the land fill, and lowering the show's carbon foot print; it gave me a large pile of mahogany plywood and clear fir lumber.
At the end of the day, when I had already half-filled a full sized van with pieces, someone alerted me to the two sides of the skiff that had been thrown out. These are two (I thought) mirror image sides of the 12' boat. I thought I would grab them, make a form to allow me to torture the shape a little, and make a one man kayak/sampan type boat with a two foot beam, instead of the skiff's four foot beam. I liked the pram-bow used on teh sampan, so that was part of the design spec. When I set up my building jig I discovered why the pieces had been thrown out. The boat has a left side and right side. The plywood shape is stiffened by chines at the top and bottom. This pair had the chines on the right side, rather than one on the right and one on the left. This made for an interesting reverse origami lesson to come up with a pair of sides with both chines on the inside.
The boat got smaller, and the buoyancy decreased, so it sat in the water lower than I wanted. So a foam false bottom was added, which meant more fiberglass and epoxy. And time.
Check out the blog for complete construction details.