A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Date: 2014 Dec 3, 07:21 -0000
That’s very helpful and interesting. Could I ask you about sextant corrections? I was thinking of “reverse correcting” the pre-computed Hps and then plotting un-corrected Hs directly on the graph to save on mental arithmetic “in-flight” . Are you plotting Hs or, Ho or what on the charts? I suspect I am being rather dim here and missing a point or 2?
When you are planning your voyage estimate your time at each waypoint and for a couple of hours either side work up curves for the sun and moon for the day and for several stars at night. See:
From: Francis Upchurch <NoReply_Upchurch@fer3.com>
Sent: Tuesday, December 2, 2014 11:36 AM
Subject: [NavList] Re: Hp by Doniol for Aircraft
I don't think any of us old romantics are seriously suggesting we do a Chichester as per 1931(he was crazy even then). I never go anywhere on my boat without multiple GPS back-ups, but just like to play with astro, celnav and the old Chichester stuff like Bygraves etc. In an emergency, the GPS rules.
Anyways, this recent thread on precomputed Hps is fascinating and I intend to try it out on my next boat trip to Scillies. I've already worked out my "waypoints" with the Bygrave and will now also test the Brown-Nassau.