Remember that the cost of a hull is a fraction of the total cost of building a boat. You have to also figure in engines, all systems, upholstery, finish of the entire interior, paint, fairing, electronics etc. Also a bare boat's speed (and 8800 lbs is light for a boat this size) is related to its weight. Once you put in 200 gallons of fuel (1400 lbs) and 200 gallons of water (1600 lbs)--you have added another 3000 lbs, and will find that the efficiency will decrease. Very difficult to compare the efficiency of a planning and a semi displacement hull, as well as a gasoline outboard to an inboard diesel. My bet is on the PDQ--and as Henry says a used PDQ will cost considerably less. Bob Austin

Agree with Bob Austin - displacement has a dramatic affect on fuel economy. For example: My 40' LOA Maxweld aluminum power cat has a planing hull. I was disappointed by the planing speed fuel economy. One of the boats ahead of mine in the production line had the identical hull and power plant, and the builder and professional delivery crew reported outstanding numbers on that boat. My boat consumed 40% more fuel. I was convinced that there was a problem with the boat, but the power plant checked out fine, and there were no obvious hull deficiencies other than it was slightly stern-heavy. I finally tracked down the owner of the previous boat. He confirmed that the numbers reported to me were indeed accurate. But there were a few differences between our boats. His was used as a day-boat by the fishing lodge he owned. Mine is a cruising/liveaboard/fishing boat. He had a minimal cabin, small battery bank, small fuel tanks, smaller water tank, no galley, tiny head, no berths, etc. etc. It was the same hull and power, but that's where the similarities ended. My boat weighs almost double what his does. So I don't feel quite so bad. Double the weight, and only 40% more fuel usage. I shouldn't complain. However, I've discovered an amazing thing. If I slow down to displacement speeds, my fuel economy is nearly 4X better. Who knew? I've occasionally run at slow speeds, but hand-steering is very tedious at that speed. I'm having an autopilot installed right now, and next spring I'll be doing my long runs, if I'm not in a hurry, at 8 kts, letting my 'third mate' handle the wheel. On the other hand, if I want to get somewhere in a hurry, and my wallet is feeling fat, I can always crank it up to 25 kts. One of the primary advantages of cats, even the planing flavor, is their ability to run very efficiently at displacement speeds, and yet run at considerably higher speeds as well. Bob Deering Juneau, Alaska On 1/10/10 6:23 PM, "Bob Austin" <thataway4@cox.net> wrote: > Remember that the cost of a hull is a fraction of the total cost of building a > boat. You have to also figure in engines, all systems, upholstery, finish of > the entire interior, paint, fairing, electronics etc. > Also a bare boat's speed (and 8800 lbs is light for a boat this size) is > related to its weight. Once you put in 200 gallons of fuel (1400 lbs) and 200 > gallons of water (1600 lbs)--you have added another 3000 lbs, and will find > that the efficiency will decrease. > > Very difficult to compare the efficiency of a planning and a semi displacement > hull, as well as a gasoline outboard to an inboard diesel. My bet is on the > PDQ--and as Henry says a used PDQ will cost considerably less. > > Bob Austin > _______________________________________________ > Power-Catamaran Mailing List