Catamaran and trimaran boat plans make it a reality to build your own catamaran or trimaran. multi-hulled sailing vessels are a special class of boat. a very different mind set is required when thinking about sailing a multi hull, let alone getting your head around building one.. Power catamaran plans and kits, catamaran plans , bruce roberts web site offers catamaran boat plans and catamaran boat kits for fiberglasss and aluminum boat designs, cut to size catamaran kits, part built boats or complete boats.. The boats were elegant and reasonably simple to build and 1000s of sets of plans were sold worldwide; every creek you went to there was a wharram. james and hanneke are still designing catamarans and many are still being built around the world..