A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Greg Rudzinski
Date: 2014 Sep 27, 11:39 -0700
Is your AH a leveled mirror type ? Or are you using a bubble optic attached to your sextant ? A water or oil AH limits me to only very bright stars such as Sirius. If you are using a bubble then 1' intercepts are exceptionally good. If using a well leveled mirror or water (oil) then 1' or better is to be expected.
Polaris changes altitude very slowly just like the Sun at or near LAN. This gives the observer plenty of time to center the body in the center of the scope field and find a perfect vertical to to the horizon. Timing is not needed to the second for Polaris. As a matter of fact you will do well even rounding the LHA of Aries to the nearest degree for entry into NA tables. The main problem with Polaris at sea is that there is a very bief window during twilight where both Polaris and a sharp horizon are visible.