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DSK
 
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Default IACC Boat speed at 30 degrees heel?

Nav wrote:
Bluster all you like but 30 degrres for max boat speed is still quite
usual.


So far, you seem to be talking about IACC boats and 'Round-the-world
racers.... now you're generalizing to all boats? These are pretty
specialized designs.

Find a quote from a racing skipper who says specifically, "Yes, we won
because we kept the boat at 30 degrees heel and more." Then maybe you'll
have something. If you are a member of a sailing club you can ask
around... oh wait, that's in the real world...

For the following quote, I'll give you 2 points (although Bart is the
official scorekeeper, he'll have to verify it) it still proves nothing
about the way 'most boats' sail IMHO.



....While a canting keel increases stability (or righting moment)
dramatically under

typical sailing conditions (say 30 degrees of heel),


its offset CG actually works against a self-righting tendency at large,
knockdown heel angles.


True because the canting keel will have similar CG geometry to a dinghy
with a hiked out crew... oops wait...

.... Accordingly, Volvo 70 Rule developers have
closely examined limitations on hull displacement and beam that affect
form stability, with additional limitations on keel weight and keel
swing angles. Each yacht shall have a designer-calculated limit of
positive stability greater than 115 degrees, with appendages positioned
in a worst-case scenario. In addition, each boat must successfully
self-right from a 180-degree inversion using only manual power to
articulate the keel."


This is rather ironic, Navvie, they are talking about LPOS not max
speed. Another oops?


http://www.perrottidesign.com/new_Volvo_Open70.html


Anyway thanks for the link. Cool pictures, I am looking forward to
seeing more forward-foil boats sailing.

Fresh Breezes- Doug King