A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Gary LaPook
Date: 2021 Oct 5, 21:30 -0700
The easiest way to fing the IC of a bubble sextant is to go down to the nearest beach, stand with the water lapping on your toes, and measure the altitude of the horizon. You should be reading negative two minutes. Compare your measured altitude with minus two and you have now determined the IC.