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Subject: Leeway angles
From: Buck Godwin (bgodwin@XXX.XXX)
Date: Tue Jul 20 1999 - 20:26:15 EDT
don't know where the table came from, but garrett gives one of the
formulas. he claims that leeway should be (approximately)
proportional to the sine of the heeling angle and inversely
proportional to the speed squared for heavy displacement boats, but
not for light and beamy ones. from model tests of one 12.2 meter
(overall) boat with a variety of sail areas, the constant of
proportionality is about 464 degree-knot**2, up to about 10 degrees of
leeway.
8 * heel / boatspeed**2 an approximation of that formula.
if someone checks ocean navigator back issues, please check the
following issue or two for a correction, just in case there was a
typo.
Section 3.5.3 of The Symmetry of Sailing by Ross Garrett also
describes methods of measuring leeway.
buck
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