NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: accuracy of automatic celestial navigation
From: Robert Eno
Date: 2002 Dec 6, 23:24 -0500
From: Robert Eno
Date: 2002 Dec 6, 23:24 -0500
We have to differentiate between observations at sea and observations on land with an artificial horizon. I agree that 2 miles at sea is acceptable and indeed satisfying, although I have known some mariners who claim that they have no problem with obtaining, consistently, accurate fixes to within less than a mile. I know that on land, I am very displeased with myself if I cannot pin myself down to within less than a mile -- even with a bubble attachment -- and I am not even all that proficient. At sea, 2 miles is fine for me, although I do like to do better if I can. There was an interesting article in Ocean Navigator several years ago in which the Captain of the ON training vessel, Ocean Star, obtained a perfect pinwheel fix at sea. Can't remember her full name: Virginia _______ but she is apparently a superb seaman and a skilled navigator. Some folks just have the touch. In the final analysis, and in looking at the discussions on how to get more accurate observations, it seems a tad overkill -- at least for PRACTICAL navigation purposes -- to carry along things like "Gavrishell dipmeters" and such. Please note that I am not ridiculing the idea but in reality, the ordinary seaman or yachtsman is probably not too concerned if s/he doesn't hit the bullseye. In mid-ocean, it just doesn't matter (except inasmuch as bragging rights over a tot of rum). Close to shore, it does, however, that's when one can start to employ coastal navigation techniques. And I can't imagine trying to wield a full sized bronze sextant with a 20 power scope. Good Lord, my 6 x scope is heavy enough! I do, however, really like the idea that an automated astro-navigation system can achieve the kind of accuracy described by Jared Sherman. In this age of GPS supremacy, it constitutes astro-navigation's "revenge of the nerds". Makes me feel warm and fuzzy all over! Robert ----- Original Message ----- From: George HuxtableTo: Sent: Friday, December 06, 2002 7:05 PM Subject: Re: accuracy of automatic celestial navigation > For those of us that sail our small craft out at sea, my opinion is that if > we can achieve a precision of 2 min, we are doing pretty well. What do > others think? > > George Huxtable.