Originally Posted by Cruisingdad
I have always thought a general rule of thumb is 2 HP for every 1000 lbs. The Catalina 380 weighs about 20k and has a 40hp engine. The 400 weigs about 24000 and has a 54 hp. I would err on the high side.
That seems to be about what most boats have, although I would say that 2 Hp for every 1000 lb (4 Hp per ton) is more like the upper limit. Our boat is 9600 lbs and has an 11 Hp diesel (2.3 Hp per ton). That being said, I've never heard anyone complain about being over