NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: The Great Circle Challenge
From: Stan K
Date: 2014 Dec 27, 08:06 -0500
From: Stan K
Date: 2014 Dec 27, 08:06 -0500
4069 looks right to me.
-----Original Message-----
From: Francis Upchurch <NoReply_Upchurch@fer3.com>
To: slk1000 <slk1000@aol.com>
Sent: Sat, Dec 27, 2014 7:41 am
Subject: [NavList] Re: The Great Circle Challenge
From: Francis Upchurch <NoReply_Upchurch@fer3.com>
To: slk1000 <slk1000@aol.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?
Francis
From: NavList@fer3.com [mailto:NavList@fer3.com] On Behalf Of Francis Upchurch
Sent: 27 December 2014 12:21
To: francisupchurch---.com
Subject: [NavList] Re: The Great Circle Challenge
Sent: 27 December 2014 12:21
To: francisupchurch---.com
Subject: [NavList] Re: The Great Circle Challenge
Apologies I made an error on the Bygrave. Several check repeats now give 4059 nm distance. 25˚55’ course.
Francis
From: NavList@fer3.com [mailto:NavList@fer3.com] On Behalf Of Francis Upchurch
Sent: 27 December 2014 09:41
To: francisupchurch---.com
Subject: [NavList] Re: The Great Circle Challenge
Sent: 27 December 2014 09:41
To: francisupchurch---.com
Subject: [NavList] Re: The Great Circle Challenge
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?
Best wishes,
Francis Upchurch
From: NavList@fer3.com [mailto:NavList@fer3.com] On Behalf Of David Pike
Sent: 26 December 2014 16:21
To: francisupchurch---.com
Subject: [NavList] The Great Circle Challenge
Sent: 26 December 2014 16:21
To: francisupchurch---.com
Subject: [NavList] The Great Circle Challenge
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
