NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: David Pike
Date: 2025 May 15, 09:35 -0700
1. The best thing would be to try both v FR’s GPS Anti-Spoof and see which I got on best with.
2. However, if that wasn’t possible, and I had to pick one purely from the photograph, I’d pick the one on the right.
My Reasons:
a. The markings on the arc stand out better.
b. The reading is so much easier to estimate. The value is between ??degrees 30 and 31’. I estimate it as ??degrees 30.7’. Done!
c. The one on the left has a five into four vernier. Each Vernier division is 12”. The value is between ??degrees 28’ and 29’. The seconds value is between 3 x 12” and 4x12”, say 3.5, =3.5x12”=42”=0.7’, which although the actual value on each sextant is a different value of degrees and minutes, is about the same as I can estimate without the Vernier. Moreover, it’s a heck of a lot of mental arithmetic to struggle with on a bumpy passage. The Brits would choose a 6 into five vernier, Then you could read your seconds direct . DaveP
