Aluminum jet boat hull plans. • aluminum hull, composite pieces per plans. mechanical mtu 16v4000 m90 marine diesels, each rated 3,650 bhp @ 2,100 rpm interior. Design, computer lofting, and kits for welded aluminum boats. specmar inc (previously specialty marine contractors) is an aluminum boat design, lofting, and kit company.. Home / boat plans & kits catalog / aluminum construction: designs all designs for aluminum construction are included here. garvey hull with center console :.