Regarding fiberglass sheathing. I rarely use it on canoes, dinghies, small boats unless they will be dragged on the ground. It adds little strength over plywood, only some protection from "wear and tear". I did use it on my 15 ft. Old Codger cruising boat as it often gets pulled up on beaches. I usually do sheath bigger boats. My method is to use 6 oz. cloth on the sides and 10 oz. on the bottoms, both overlapping at the chines. I eliminate the strip of cloth taping there.