NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Leeway angles
From: Buck Godwin
Date: 1999 Jul 20, 6:26 PM
From: Buck Godwin
Date: 1999 Jul 20, 6:26 PM
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