Hi

"Stephen Baker" skrev i en meddelelse
...
Ron whines (and spells my name wrong to boot!):

Steven, Tell um why please.

Well, since you ask, and since this is a Sunday so I can't charge for
this.....

There are a "few" variables that affect the placement of CE. You have to
allow
for things like the actual centre of effort not being the centre of area
(although this is simpler because that is the case for the keel as well), and
the fact that the sails are almost never on centreline, so the line of force
(vector for the tech-heads) doesn't act in the same plane as the drawing.
That last one is the kicker here. If you draw the boat from above, and draw
the sails in "operating" position, and then their respective force vectors,
you
will note that the resultant is now acting _behind_ the CLR, giving some
weather helm (vastly preferable to the alternative) in most cases. Boats like
Open Class 50s and 60s, using autopilots most of their sailing lives, will
have
little, if any helm at all. And the lucky designer is the one that has
figured
out his own little system, and it works ;-))

Don't you just design the boat so it perform well ?

P.C.