A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Date: 2014 Dec 27, 20:38 -0000
In that case, the Bygrave looks accurate as per Doniol, and at 2 minutes, much quicker. But the very primitive Brown –Nassau prototype, looks incredibly good. I suspect the definitive , final version will be much better. Greg and Hanno’s Doniol remain my favourite long hand method, but as I use it , no contest time wise, with Bygrave and now more convincely, the newly re-discovered Brown-Nassau. I suspect that will beat anything in the final version.
Watch this space.
4069 looks right to me.
From: Francis Upchurch <NoReply_Upchurch@fer3.com>
To: slk1000 <slk1000---.com>
Sent: Sat, Dec 27, 2014 7:41 am
Subject: [NavList] Re: The Great Circle Challenge
Having a bad day. Repeat Bygraves give 4069nm.
Which is correct?
Apologies I made an error on the Bygrave. Several check repeats now give 4059 nm distance. 25˚55’ course.
Merry Xmas Navlist folk.
The following probably adversely affected by seasonal excesses.
Bygrave: Course 25˚55’, dist 4063nm. Took 2 minutes. (substitute Dec= arrival lat, LHA (t) = difference longitude.)
Brown-Nassau prototype: Course 26˚. Dist 4070nm. Took 1min 30 secs approx.
What is the best ,correct answer?
The Great Circle Challenge
Clearly, from recent posts, we all have a favoured way of solving great circle sailings (which we’ll probably never use for real). Let’s put them to the test by trying something a bit more complicated like a southern to northern hemisphere crossing combined with a crossing of 180degrees E/W. How about emulating Captain Cook by travelling from Cook Strait (CS), New Zealand to Waimea Bay (WB), Kauai, Hawaii? Cook followed the pretty route, but we’ll go direct by great circle. The coordinates are CS 41d 30’S, 174d30’E to WB 21d57’N, 159d 40’W. Use your favourite method and report back on your answer, the time it took you, and any difficulties encountered.
I’ll stick with the diagram method, because at least I’ll know what I’m trying to prove, and I won’t have as many rules to remember and apply which might or might not work. Dave