NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: What do offshore recreational navigators really do?
From: Henry Halboth
Date: 2005 Jun 6, 13:50 -0400
From: Henry Halboth
Date: 2005 Jun 6, 13:50 -0400
It can only be said that it takes quite a bit of discipline, not to mention responsibility, for one to adhere to a rigid schedule of sight taking if not obliged of necessity to do so. On extended voyages, when following a great circle track, frequent fixes were considered necessary, perhaps appropriate is a better term, to keep the vessel on track - thus mini zing fuel expenditure and time enroute, and I am talking about within a few miles of the track. It was quite customary for me to take an average of from 10 to 14 sights a day to accomplish this end - specifically 5-AM stars + 3-AM suns, crossed with the moon or venus if available + noon Latitude + 1-PM sun to check on speed, again crossed with the moon or venus if available + 5-PM stars. What others may or may not do is purely their business, but at one time both commercial and naval ships required performance. I am sure that otherwise, on a long passage without expected navigational hazards, the major portion of the passage could be made by DR, with but a few sights in preparation for landfall. Henry On Mon, 6 Jun 2005 08:18:38 -0700 Lu Abelwrites: > Henry Halboth noted the tradition of 0800, 1200 and 2000 position > reports to the captain of commercial and military ships, along with > a > tradition of a noon sun shot. I'm 100 years ago one could also have > seen several sextants on the bridge wings of any such ship at dawn > and > dusk, trying to bring down as many bodies as possible to get a > perfect > "pinwheel" fix. > > These navigators had an awesome responsibility of keeping safe a > very > expensive ship with hundreds of people aboard, so I can certainly > understand their meticulous behavior. They were also navigating > large > ships with long turning times and deep draft, so "whoops, there's a > hazard, hard alee" wasn't an option as it might be on a smaller > recreational craft > > A year ago or so someone told me (and, unfortunately, I don't recall > who > it was, so I can't go back for more details) that a recreational > sailing > magazine had polled recreational sailors who had made long offshore > passages (including quite a few circumnavigators). Of those who > regularly used celestial, the vast majority reported that they > simply > took morning, noon-ish, and afternoon sun shots and advanced the > resultant LOPs. No star shots, no fussing at dawn and dusk, just > the > sun. While I didn't question my friend, I'd assume these folks > might > also take daytime moon shots. > > I suspect their theory was that in the middle of the ocean, knowing > position to a few dozen miles was more than enough. I also note > that in > a bouncing small craft, taking a sight with any degree of accuracy > is > extremely difficult. > > Comments? Especially from anyone on this list who has made long > offshore passages on a small craft? >