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Old 05-09-2003
DuaneIsing DuaneIsing is offline
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Factors influencing boat balance

The current discussion of mast rake and its effects on yaw balance (weather vs. lee helm) leads me to a question.

Take an elevation (side) view of a boat and mark the centers of effort (sail plan) and center of lateral resistance (keel and underbody) - assuming you know where these are for the sake of this question. If considering only the component of force perpendicular to the centerline plane of the boat, you can see how the boat should balance when the applicable force vectors are applied.

But the resultant force from the sails is not usually perpendicular to that centerline plane. Most times there is a foward component, as well, especially if your sails are in good shape and trimmed properly. For example, when you are close-hauled and allowing the boat to heel quite a bit, the forward force components of your sail plan are now acting at a fair distance from the "pivot point" (which I assume is somewhere near the CG of the boat).

My questions: Isn''t that behavior a greater cause of weather helm than the mast rake? And isn''t that one of the reasons not to sail with too much heel?

I''m sure people have written treatises on this subject; I have just not read any of them. Any comments?
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