Lost tech of Ancients

Discussion in 'OnBoard Electronics & Controls' started by Yobarnacle, Dec 10, 2011.

  1. Yobarnacle
    Joined: Nov 2011
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    Yobarnacle Senior Member holding true course

    from a small vesel...30 to 50 ft loa
     
  2. michael pierzga
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    Location: spain

    michael pierzga Senior Member

    Radar is the weapon. I cant imagine navigating without it. The radar GPS interface allows bold navigation in poor conditions.... like identifying the MoA welcome buoy as it dips into the troughs of three meter waves then disappears into the clutter. The GPS lolli pop identifies the buoy allowing you to fiddle knobs until you mark it..


    When I was younger...finding Bermuda with a sextant meant getting close, then waiting for the ships or aircraft trails to point you in the right direction
     
  3. Yobarnacle
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    Yobarnacle Senior Member holding true course

    I'm as addicted to electronics as anyone. I love my Arpa radars, and 22 inch electronic chart plotter with AIS and DGPS. I love my satelite phone, and Email at sea and the color weather charts from the private weather service. All the toys I can get, as long as the company pays for them.
    But I don't want to forget my original training. A power failure means all the electronics go dark and mute.
     
  4. Yobarnacle
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    Yobarnacle Senior Member holding true course

    goodnight, its 5:03 am I'm off to lala land for about 5 hours. Just can't sleep longer than that. Too many years of watch and watch, 6 and 6
     
  5. michael pierzga
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    michael pierzga Senior Member

    Longitude at noon . At local apparent noon, longitude is not able to be determined by recording Meridian passage .

    You can observe max altitude ,but not the presice time of meridian passage because the arc of the sun is so flat. The sun will be Several minutes on top of its hump before falling. Meridian passage will be sometime in this flat arc.

    The technique, longitude at noon , uses equal altitudes and equal times to determine the precise time of meridian passage. Its better explained with books and illistrations.

    The technique is very simple and represents a typical small craft navigators day with the sun.
     

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  6. Yobarnacle
    Joined: Nov 2011
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    Yobarnacle Senior Member holding true course

    Excellent.
    In the "lessons" I posted, I over simplified so as not to cause sensory overload. The 'lessons' were directed at readers who don't know celestial and too intimidated by "spherical trigonometry" to attempt to learn. I wanted to be encouraging. When I'm teaching an interested hand on board, I suggest he pick a whole degree of longitude from his LAN worksheet altitudes & times. The sun moves a degree west every 4 minutes. A whole degree longitude is accurate within that degree. Like uncorrected Polaris. IMHO.
    But "my" lessons are over. Now I'm the student. Please continue small craft navigation.
     
  7. hoytedow
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    hoytedow Wood Butcher

    This is a good thread to review. I had forgotten all about it.
    The astronomy department at University of South Florida had several aeronautical sextants when I attended there back in the days.
     
  8. Yobarnacle
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    Yobarnacle Senior Member holding true course

    Old threads are haunted by dead OPs wandering their pages ranting!
     
  9. tom kane
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    Location: Hamilton.New Zealand.

    tom kane Senior Member

    https://sextantbook.com/category/unusual-left-handed-sextant/

    As stated the most important instrument on the bridge is the EYES of the navigator so the very first thing a navigator must do is is to find out which of his EYES is the "RIGHT" eye to use for sightings.
    Many navigators may be using their "WRONG" eye with dire or inaccurate results.
    Many people automatically put a sextant up to their right eye thinking that is OK.
     
    Last edited: Mar 6, 2016
  10. Yobarnacle
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    Yobarnacle Senior Member holding true course

    Latin for right hand is 'Dexter" from which words like dexterous and ambidextrous are derived.
    You would NEVER want to look through the sextant with your left eye.
    You would have a "sinister" view of things.
    Can you guess from previous sentence, Latin for left handed?
     
  11. Mr Efficiency
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    Mr Efficiency Senior Member

    I don't do latin but I seem to remember "sinistral" or something like that. Right is "right" (correct) left is what remains. It is something to ponder, how left-handedness became such a maligned thing in the past, maybe relates to the left handed being biased toward right brain functions. Kids were belted for writing with the left hand in my primary school days.
     
  12. Yobarnacle
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    Yobarnacle Senior Member holding true course

    lefthanded people are a small percent of the population.
    That made them odd.
    Odd is suspicious.
    suspicious became synonymous with "sinister".

    That's the way I figure it. Maybe wrong.
     
  13. hoytedow
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    hoytedow Wood Butcher

    If I use my right eye to navigate, my sextant might as well be a cabbage. ;)
    I guess my oculus sinester gives me a sinister view on everything.
     
  14. Yobarnacle
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    Yobarnacle Senior Member holding true course

    Hah! You are an ETREMELY sinister person, Hoyt! None of your views are right!
     

  15. tom kane
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    tom kane Senior Member

    Just use your "correct dominant" eye when using a sexytant and miss all of those rocks and hard places.
    My left eye is my dominant eye so yes I must different to the average.
    Some people are Professionals and some are Perfectionists.
     
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