One sheet sampan: free boat plans and building instructions. a small dory out of just two sheets of plywood. free boat plans and building instructions.. Plans for small portable boats. primarily from one sheet of 1/4 inch plywood. get kids interested in boat construction. the plans are free for the. Plus a lot of people there have built boats from plywood already and free boating….(at least the boat 2 plywood sheet boat plans this one was built.