[Rhodes22-list] Sailing suggestion.

[Ronald Lipton]

The hull speed formula has nothing to do with hull shape. It is based on the
relation between wavelenght and propogation velocity of water waves.  At
"hull speed" the boat is moving in the trough of a co-moving wave formed by
the boat's motion in the water.  To go faster the boat must climb up the 
crest
of the wave.  This needs significant energy.  The amount of energy will 
depend
on the boat displacement, the height of the wave generated, and the shape of 
the
hull.  That's a hard thing to calculate.

Ron
----- Original Message ----- 
From: "David Bradley" <dwbrad at gmail.com>
To: "The Rhodes 22 mail list" <rhodes22-list at rhodes22.org>
Sent: Thursday, April 20, 2006 9:39 AM
Subject: Re: [Rhodes22-list] Sailing suggestion.


Bob, thanks.  I had thought that the hull speed formula assumed an "average"
hull shape, and that one of the factors is the mass below the water line.
By heeling a typical keel boat aren't you moving mass above the water line?

Dave


On 4/19/06, Bob Weber <ruba1811 at hotmail.com> wrote:
>
> Dave, Flat bottom = 18 foot of waterline
> Healed bottom = 19 foot of waterline
> Who Cares?
> The limitation of your maximum speed is based on waterline - Longer boats
> can go faster
> Hull speed = Square root of the wateriine * 1.3 (51/2 kn) flat or 
> 5.7heeled
>
> If you ever see sailors on the lee side of the boat using their weight to
> heel the boat on light wind days that is the principle they are going
> from.
>
> Bob Weber
>
>
> >From: "David Bradley" <dwbrad at gmail.com>
> >Reply-To: The Rhodes 22 mail list <rhodes22-list at rhodes22.org>
> >To: "The Rhodes 22 mail list" <rhodes22-list at rhodes22.org>
> >Subject: Re: [Rhodes22-list] Sailing suggestion.
> >Date: Tue, 18 Apr 2006 23:34:11 +0100
> >
> >Bill, it sure makes sense to me, just in terms of physics.  Flat bottom =
> >less friction.  Buried side = more friction.  Of course, I was a
> marketing
> >major so what the hell do I know about physics?
> >
> >Dave B.
> >
> >
> >On 4/18/06, Peter Thorn <pthorn at nc.rr.com> wrote:
> > >
> > > Nope.  I agree with you Bill.
> > >
> > > PT
> > >
> > > ----- Original Message -----
> > > From: "Bill Effros" <bill at effros.com>
> > > To: "The Rhodes 22 mail list" <rhodes22-list at rhodes22.org>
> > > Sent: Tuesday, April 18, 2006 11:48 AM
> > > Subject: Re: [Rhodes22-list] Sailing suggestion.
> > >
> > >
> > > > Jay believes me, but he may be the only one.
> > > >
> > > > Bill Effros
> > > >
> > > > R22RumRunner at aol.com wrote:
> > > > > Bill,
> > > > > Nobody on this lists believes you. A R22 does not sail fast flat.
> It
> > > > > requires about thirty degrees of heel to get the wind in the sails
> >and
> > > really  get
> > > > > her moving. I'd like to see you sail flat in a 10 mph wind. It can
> >be
> > > done,  but
> > > > > only by the faint of heart.
> > > > >
> > > > > Rummy
> > > > > __________________________________________________
> > > > > Use Rhodes22-list at rhodes22.org, Help? www.rhodes22.org/list
> > > > >
> > > > >
> > > > __________________________________________________
> > > > Use Rhodes22-list at rhodes22.org, Help? www.rhodes22.org/list
> > >
> > > __________________________________________________
> > > Use Rhodes22-list at rhodes22.org, Help? www.rhodes22.org/list
> > >
> >
> >
> >
> >--
> >David Bradley
> >203.253.9973
> >dwbrad at gmail.com
> >__________________________________________________
> >Use Rhodes22-list at rhodes22.org, Help? www.rhodes22.org/list
>
>
> __________________________________________________
> Use Rhodes22-list at rhodes22.org, Help? www.rhodes22.org/list
>



--
David Bradley
203.253.9973
dwbrad at gmail.com
__________________________________________________
Use Rhodes22-list at rhodes22.org, Help? www.rhodes22.org/list