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    Sextant accuracy with short distance to horizon
    From: Richard B. Emerson
    Date: 2001 Jun 21, 8:47 AM

    Dan Allen writes:
    [...]
     > This led me to think more about possible inaccuracies of using a horizon
     > that is very close rather than naturally far away.  That is, typically you
     > use a horizon that is at the limit of your vision, perhaps 20 miles away.
    [...]
    
    While you're in Bowditch, check out table 12, "Distance of the
    Horizon".  Assuming you're 6' tall and standing on a deck 4' off the
    water, for a total height of eye of 10', the horizon is 3.7 miles
    off.  A twenty mile horizon requires a height of eye of something like
    300'.  And clear air.  [grin]
    
    Rick
    S/v One With The Wind, Baba 35
    

       
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