Join Date: Feb 2011
Location: San Francisco Bay area
Thanked 57 Times in 57 Posts
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Re: Wind Vane Calibration
I think you can do a crude check for accuracy, by taking two measurements :
1) Motoring directly into the wind
2) Motoring directly downwind
The two wind speeds measured should differ by 2x your motoring speed.
IE, you motor at 6 kts, readings of 20 kts and 8 kts indicate an accurate wind meter. (difference was 12 kts, 2 x motoring speed) (true wind was 14 kts)
If your meter is really reading 50% over without calibration, you should get 30 kts and 12 kts in the same scenario.
Edit : you need true wind that exceeds your motoring speed, to do this.
Edit edit : you also need no current, or at least known current.
Bristol 31.1, San Francisco Bay
Last edited by MarkSF; 12-02-2013 at 06:03 PM.