Join Date: May 2002
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Factors influencing boat balance
DuaneIsing, don''t let Denr talk you out of thinking about such things. I''m not completely clear about your theory, but will volunteer what think I know, and maybe someone else will help.
As best I can determine, the relationship between the center of effort of the sails and the center of lateral resistance of the keel and underbody, change constantly as the boat bobs up and down the waves. When you adjust the rake of the mast in order to reduce weather helm, you are changing the relationship between the CE and CLR *on average.* Any variations in that relationship that result from the movement of the boat over the waves are only momentary in their effect, and relatively insignificant. You adjust the rake of the mast in order to reduce the *average* amount of drag caused by excessive weather helm.
I''m not sure whether heeling changes the relationship between the CE and the CLR (and maybe someone else has some thoughts on that question), but even if it does, I doubt that the changed relationship is a significant cause of excessive weather helm or drag. IMHO, when the boat heels, the increased drag is caused primarily by the change in the shape of the underwater surfaces of the boat, and not by the changed relationship between the CE and CLR.
The CE represents the center of *all* the force vectors acting upon the sail, including any forward component. Therefore, the fact that there is a forward component is taken into account, and doesn''t change the relationship between the CE and CLR.