On Sat, 30 Jun 2007 23:37:46 GMT, Dan wrote:

Total weight, boat+motor+people+fuel+gear is really a better measure.
Figure about 1 hp for every 30 to 40 lbs of total weight for average
performance.

Where did you find that? 140HP for a 5000# loaded boat?

More like 170 hp if you use the lower end of the estimate.

There's no science in it at all, just a guesstimate based on my
personal experiences with a number of different boats. I'd be the
first to agree that it will not necessarily yield optimal performance
or engine life but will certainly get most boats up on plane and
moving half way decently. Don't under estimate the weight of people,
fuel and gear. It adds up very quickly, and brings required
horsepower along with it.