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post #15 of Old 07-30-2011
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Originally Posted by billyruffn View Post
Enough with the math! Vectors, smectors!

Put the coordinates of Point B in the GPS, note the bearing thereto, use that heading to start and after a few minutes note the COG on the GPS. Adjust your heading so that the COG equals the bearing to Point B.

And dontí tell me about losing power and GPS failure and all that. If that happens youíre just SOL.

PS -- it helps to plot a line from A to B on a real chart so you can be sure there are no hard things lurking along the rhumb line.

But seriously, in small boats itís hard enough to steer within 10 degrees of the desired heading. So pre-planning a few degrees of windage is an interesting exercise, but it shouldnít replace knowing where you are and where youíre going in real time. Thatís what makes GPS so great!
I'm with Billyruffin here! I cetainly use GPS to take the sigmoid curve out of any crossing of a currect vector or adjustment for the effects of leeway. I did not respond up in the second post with the thought that this was an exercise from a workbook or course. The answer I gave was the practical application I used in the 70's for crossing the Gulfstream with RDF and dead reckoning before GPS. My practical application of leeway undersail was always to adjust according to my RDF fix along with the intuitive development that all sailors have knowing that, especially when close hauled, you are not headed as the bow points. I favor the means of calulating this adjustment for leeway and respect the course work, but it's not a function in today's practical application. Take care and joy, Aythya crew
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