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Thread: Davis sextant

  1. #1
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    Default Davis sextant

    I have one of the Davis cheapo plastic sextants for learning celestiial navigation..free. PM me if you want it.

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    Learning how to take a noon sun sight is not THAT hard, BTW.
    S-2 7.9: "Wildcat of Loch Awe"
    1968 Selmer Series 9 B-flat and A clarinets
    1962Buesher "Aristocrat" tenor saxophone
    Piper One Design 24, Hull #35; "Alpha"

  2. #2
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  3. #3
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    Default

    Quote Originally Posted by jamottep View Post
    Yes. Same Sextant. This one doesn't have the box, but it does have a copy of HO245 worksheet...or maybe HO215 that you can run off 50 copies of. You need the work sheet, either HO 245 or HO 215 (or you can make your own, like I did), correction tables for the year you're using them, and either northern or southern hemisphere, and a calculator.

    Used books on how to do it are available for next to nothing on ebay.
    This website explains how to do it and also gives away the celestial tables for free in Excel format:
    https://www.nauticalalmanac.it/en/na...avigation.html

    That's a bluidy lot of $$ for that kit. But then, I'm cheap. Setting a big, fat cheap and ugly digital watch to UT is easy. You sit down with the watch and a website that shows you GMT...oops..UT... and set it. The navigation tables used to be printed in spiral bound paper book format, and they were large and clunky but you can get them in much smaller book form, now. You can also store them on your phone or tablet, as long as you have a mobile version of Excel to use. A plastic tub of the appropriate size from any hardware store is just a few dollars.

    I never learned how to do star sights, though supposedly Venus is not that hard. I just learned how to take noon sun sights. What inspired me was an activity in my Physical Oceanography class where the instructor took the whole class, all 15 of us, NONE of which had ever touched a sextant before, and we walked out on the beach about an hour before U.T. . We all had a chance to practice taking a sight once or twice and then about twenty minutes before U.T. noon, we just swapped off taking sights about one a minute while another class member wrote down the numbers and another class member kept their eye on a watch. We got about 30 sights, both before and after U.T. noon, went back into the classroom and graphed them. There was UT Noon, as plain as day.

    If WE could do it....then I could do it by myself. So in 1996, and again in 2004...I did. I'll probably brush up with my nicer Davis sextant and my instruction book and so on so that I can do it again next year, but I have no use for this one.
    Last edited by AlanH; 04-20-2020 at 09:03 AM.
    S-2 7.9: "Wildcat of Loch Awe"
    1968 Selmer Series 9 B-flat and A clarinets
    1962Buesher "Aristocrat" tenor saxophone
    Piper One Design 24, Hull #35; "Alpha"

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