On Tue, 28 Aug 2007 20:34:28 -0500, in message

"KLC Lewis" wrote:


"Wayne.B" wrote in message
.. .
On Tue, 28 Aug 2007 19:44:11 -0500, "KLC Lewis"
wrote:

Sure there are -- but they aren't displacement hulls, either.

That gets you into a new discussion about what is a displacement hull.

I used to race on a boat called a B-29 that had a conventional lead
keel and a conventional spinnaker, a displacement hull to all
appearances. Sail area was a bit on the high side however, and on a
windy broad reach it could get onto plane and do 18 kts, about 3x hull
speed.

It strikes me that a boat that can get onto plane isn't a displacement hull,
all appearances aside. :-)

Yes that's true, if you define boats that significantly exceed 1.34
sqrt(LWL) out of the category. There are, however, lots of boats that
depend on a ballast keel for stability, that typically beat to weather
in displacement mode, and can still go through the water much more
quickly in the right conditions.

And going back to my original comment that sparked all this: The vast
majority of the sailboats I'm aware of do have a higher top speed
under sail than under power.

Ryk