About the wood: I know some guys who have built the little Cape Cod Frosty boats. http://www.capecodfrosty.org They buy luan door skins and cover the bottoms with very light cloth, then epoxy. Not fiberglass cloth, just any colorful print and very light weight. The hull looks likes like a shrunken Opti and grown men race them in the winter...in New England! So my question is, do we really need to use expensive marine ply or can we get by using cheap off the shelf stuff from Home Depot, with lots of epoxy to stiffen it up? Or, is the marine ply essential for strength? BTW, most guys who build wooden Opti's use regular plywood, not marine ply.