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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Level of observation accuracy in medium seas
From: Frank Reed CT
Date: 2004 Jul 22, 21:37 EDT
From: Frank Reed CT
Date: 2004 Jul 22, 21:37 EDT
"Did a noon sun shoot within seconds of local noon with 0 magnification sight
tube."
Just curious, did you do anything to verify your calculation that it was local noon? Did you check the altitude before and after to see that it was lower?
Generally, the limiting factor for accuracy is the horizon itself. It takes practice when there are significant waves getting used to picking off altitudes at the moment when you're seeing something approximating a true horizon. Beyond that refraction can shift the horizon up and down in ways that "dip" tables only partially correct. You could count +/-1.5 minutes as very good.
Frank R
[ ] Mystic, Connecticut
[X] Chicago, Illinois
tube."
Just curious, did you do anything to verify your calculation that it was local noon? Did you check the altitude before and after to see that it was lower?
Generally, the limiting factor for accuracy is the horizon itself. It takes practice when there are significant waves getting used to picking off altitudes at the moment when you're seeing something approximating a true horizon. Beyond that refraction can shift the horizon up and down in ways that "dip" tables only partially correct. You could count +/-1.5 minutes as very good.
Frank R
[ ] Mystic, Connecticut
[X] Chicago, Illinois
