"Larry" wrote in message
...
nom=de=plume wrote:
wrote in message
...

On Fri, 16 Apr 2010 21:01:09 -0700, "nom=de=plume"
wrote:


.. wouldn't a newer boat in the
size I mentioned from a reputable US manufacturer be powered properly?

This is what Froggy is saying "properly" depends on which side of the
compromise you want to come down on. You can have a fast power boat
with sails or a fast sailboat with a motor but both at the same time
is hard to do.


My understanding is that the engine on a cruising type boat would be able
to
bring the boat to "hull" speed. You can't really go faster than that, so
I
suppose the appropriate engine would be one that could do that (or nearly
so)? 1.34 x sq. rt of water line? So, assuming there's overhang on a 42'
boat, say the water line is 40' the max speed would be about 8.5. Of
course,
if it were not pushing all the water, skimming, then you could go faster.


It's not that simple. Size is one thing. Then there is displacement,
hull design, load distribution, etc. Even those factors don't limit
speed.

I really hope this isn't a troll or I'm wasting my time...

Imagine a cruise ship. They have displacement hulls. They don't "skim"
or plane (the correct term). Their speed is not limited solely by hull
design. If they add more HP, the ship will move faster.

You are looking at a sailboat, right? Why all of this interest in speed
from the diesel?

Cruise ships go slower than hull speed. But hull speed is pretty high on a
1000' long ship.