A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Jim Hickey
Date: 2017 Apr 19, 05:24 -0700
I have encountered several occassions when taking sights where the horizon was extremely sharp and what I think we would all consider ideal yet, when scanning along the horizon, I could see a distinct change rather like looking at the horizon through a sextant set at 3 or 4 minutes off zero. What has always concerned me is that I can easily see situations where you would not necessarily be aware of issue and could assign greater confidence to the sights taken under such conditions.
I have also wondered how much of an issue this was particularily for polar explorers.