Design, computer lofting, and kits for welded aluminum boats. specmar inc (previously specialty marine contractors) is an aluminum boat design, lofting, and kit company.. Premium cnc boat kits in aluminum alloy and steel welcome to metal boat kits! we offer premium quality stock boat kits in aluminum alloy and steel.. Boat plans & kits catalog; new all designs for aluminum construction are included here. read our free article on aluminum boat building, here..