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    Re: What do offshore recreational navigators really do?
    From: Joel Jacobs
    Date: 2005 Jun 6, 17:24 +0000
    Lu,
     
    I think common practice, is just as I said. It depends on your training. I doubt Doug or Henry would go this way, but there was a long period of time when navigators practiced only Latitude Sailing and accomplished some  remarkable feats. So, if it suits you, one sight per day will get you where you're going.
     
    When in the open ocean, there is no great need for precise position fixing. I have said that many times on this list. On the other hand, knowing where you are allows you to steer a more direct course, play the weather angles if in a sailboat, and foreshorten the length of a passage. From my vantage point, these are worthy objectives unless you like to spend your time at sea rather than sight seeing, and burn more rather than less fuel.
     
    Joel Jacobs
     
     
    --
    Visit our website
    http://www.landandseacollection.com


    -------------- Original message from Lu Abel <lunav{at}ABELHOME.NET>: --------------


    > Joel:
    >
    > What you relate is what a "good" offshore navigator might do -- pre-plan
    > sights, try for a true fix rather than LOPs, etc, etc.
    >
    > But there's "good" and there's "good enough" and there's "common
    > practice."
    >
    > I was interested in the "common practice" end of things.
    >
    > Lu Abel
    >
    > Yourname Here wrote:
    > > Some further comments.
    > >
    > > What I meant to say when I referred to yachties was that a person's
    > > training would dictate how he spaced his sights throughout the day, what
    > > he chose to shoot, and how frequently he took them.
    > >
    > > Also, I failed to respond to the questions about shooting from small
    > ! > craft. These are not in order of importance, but should improve the
    > > accuracy of your sights from that platform.
    > >
    > > Plan you sights beforehand, and use precalcualted altitudes and azimuths
    > > when appropriate.
    > >
    > > 1. Select a compfortable and secure spot where you are well braced so
    > > you don't have fear of your own safety and be standing.
    > > 2. If possible have a time keeper record the sights
    > > 3. Only shoot from the crest of a wave, never the trough
    > > 4. Take 3 sights in sequence of each body and average the results.
    > > 5. When doing stars, shoot away from a setting sun first in the evening,
    > > and towards a rising sun first in the morning.
    > > 6. Check your index error at the end of daytime sights and before taking
    > > twilight sights.
    > >
    > > In case you were wondering, we did not have a! SatNav, Magnavox 4102 or
    > > otherwise on board.
    > >
    > > Joel Jacobs
    > >
    > >
    > > --
    > > Visit our website
    > > http://www.landandseacollection.com
    > >
    > >
    > > -------------- Original message from Lu Abel :
    > > --------------
    > >
    > >
    > > > 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 responsi! bility 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 small! er
    > > > 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? *
    > >
       
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