View Single Post
  #2   Report Post  
MC
 
Posts: n/a
Default What makes a boat weatherly?

No, I'm afraid you are wrong. The turning moment which causes the boat
to heel has a component to windward. If the rudder is neutral it adds no
lift of couse and is simply feathered in the water flow. Perhaps you
might like to consider the rudder as a wing: the angle of attack to the
water flow causes lift (and drag)?

Cheers



Matt Colie wrote:

Close, but not quite the case. The rudder can not provide any
significant lift on its own.
Any rudder angle adds drag and any rudder angle effects heal. Rudder to
correct weather helm increases healing monemt.
What is really happening is that the weather helm introduces an attack
angle for the keel. What you actually want to do is set the boat up to
balance with a heading that is a little higher than desired course. When
the rudder brings the track back to course, you are left with the foil
(keel)at a small attack angle. This works on all hulls, but is most
apparent on fin keel boats.
Matt Colie -www.yachtek.com


Martin Baxter wrote:

MC wrote:

DSK wrote:



while most should know that the rake of the mast affects C of E and the
degree of weather helm, I'll guess that many do knot know that by giving
the boat some weather helm she climbs to windward better as the rudder
adds lift.





I believe this to be true for full keels, but how does it work with a
fin keel?

Cheers
Marty