[Admins, feel free to move this thread if needed] Something I have noticed about most Catamarans; While many of them have wider beams than mono-hulls of equal length, rarely do I see them with a close length to width ratio. Typically the range about 2.5: to 3:1. Is there a structural reason for this? Length:width ratios H2X YACHTS: MCAT 88' 2.4:1 Horizon Yacht's PC-58 Catamaran 2.43:1 Axcell 65' Hybrid-Air Power Catamaran 2.9:1 Horizon 80' Catamaran Yacht 2.97:1 Curvelle 33-meter Catamaran 3.66~ These two are kinda getting there: AfriCat 420 Catamaran 1.9:1 (power) Havana 72' Sailing Cat 1.8:1 (sail) My dream yacht is a cat. More a trawler-cat, as she's meant to cruise in full displacement at about 6-8 knots over a great distance (about 6,000nm). My ideal LOA to Beam ratio is about 1.625:1, with an length of 88' and a beam of 55'. As the thread title says, "A true Fat Cat". This would also break the typical mold of many cats, by having several decks. The two hulls would house the crew quarters, engine rooms, fuel, water, holding tanks, and tender/toy garages. Next deck up, two vip staterooms, 4 guest cabins. Another deck up. the master, galley (yes, i'm in North America) , formal dining, salon, and cockpit. Up yet one more deck and you have the pilot house with Portuguese bridge, and a long open air covered deck thats roof is covered in solar panels (about 50 kw worth). Propulsion would be from a hybrid diesel electric system. Electric motors (magnomatic PDD, highly efficient, high torque, medium rpm motor) would drive the shafts, CP props would make best use of that torque, and the solar would run things most of the time. If the owner (me) is content (yes i am) to trawl along at 6 or so knots, then the generators will see very little use. A large (500kWh) LiFePo4 battery pack will supply all the electrical needs of the boat. The solar will charge the batteries, and if they gets too low from extended navigation at night, the generators will kick on charge them back up. They will also come on if the boat goes over a selected speed to protect the batteries. Your thoughts?