Boat plans for power, sail and small boats. free boat plans. boat kits and supplies plus the best boat building technical support.. Boat plans and boat designs from select naval architects, yacht designers, and marine architects. powerboat plans, sailboat plans, monohull, multihull, and trihull. Pt boat plans for the famous pt 109 offered in 1:32, 1:24 and 1:16 scale – buy and download a relatively easy-to-build semi scale blueprint of an elco 80-footer..