NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: David Pike
Date: 2026 Jul 30, 02:36 -0700
Patrick Twohy
Thank you for your results and feedback. I really must put some astro sheets together. They will be much faster than trying to remember. I used all but my very last Vulcan (the aircraft not the planet) one many years ago. I’m saving that one for posterity.
I didn’t really understand “The REAL PUZZLE: What is the 0300 fix to the nearest half a mile?” Surely, if we are still at anchor, we are in the same place we were at 01.17 and at 02.51. If we’ve moved, we won’t have travelled much further than a mile in nine minutes, even if the anchor came up like a rocket. If all that was meant was “what will Hs be at 03.00”, we know X the sub solar point from GHA and dec, and we now know Z from our lat & long. Isn’t it just a side-angle-side PZX spherical triangle to solve, which I’ll have a crack at now, if I can find the appropriate Wiki page with all the formulae on. I’ll use the mean of Lars’ and Geoff’s lat & long, because they’re invariably correct.
I did that and came up with Hs at 03.00 ought to be 51°37.1' (the same as Geoff Hitchcox). See photo below. DaveP
