What is the best material to build a blue water catamaran?
I don’t really know for sure what you asking here… Do you really mean best “material” or best “method”? If you are building it yourself – you will find that fiberglass over wood is really impossible to beat. With today’s high tech boat epoxy, encapsulating and laminating all your wood, plywood, and then gluing it all together with epoxy not only makes for easy construction, but also for a very safe and protected (no more wood rot, worms, water damage etc.) and a very strong vessel. Wood – pound for pound – encapsulated and laminated with epoxy is the very strongest material you can use. It will actually out last both aluminum and steel. In addition, since all wood floats, the entire weight of your hull below the water line has a neutral affect on the weight of your vessel. I have built too many boats. lol My last two were both catamarans, 48′ and 44′ respectively. Both were built as full-time live a-boards and for voyaging on the open sea. Both were built using plywood vs planking, a