: OK but how do you build them?

In theory you could carve it all from a solid chunk of wood just like the minicell seats. That would waste a lot of lumber. So you use laminations to remove the bulk of the material. Then carve it to shape and then skin it with a layer of glass on each side. The edges of the laminations help guide you during the carving. The patterns for mine come off a 3D model.

For the first one I used horizontal laminations. It worked OK...
http://clearstreamwood.com/WordPress/portfolio/parts-for-canoes-kayaks/2007-kayak-parts-for-pat-nj

The rest have used vertical.http://clearstreamwood.com/WordPress/projects/200709gmm_nereida/nereida-njord-the-wooden-seat

A CNC router would make this a LOT easier! :)