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    Re: Sextant Positions versus Map Datums?
    From: Rodney Myrvaagnes
    Date: 2002 Jan 15, 12:49 PM

    On Tue, 15 Jan 2002 13:04:57 -0500, Jared Sherman wrote:
    
    >If NAD27 and WGS84 disagree by a mile, then wouldn't the "most accurate" 
    sextant position still either be off by a mile, or have been
    off by a mile? Or maybe still be off wherever the map datum doesn't match a "spherical earth" model?
    >
    
    AFIK, the difference between those two particular datums isn't big enough to 
    be detected in normal sextant use. The problem of
    horizontal chart errors is more likely to occur with charts surveyed in 
    isolation by Capt. Cook, for example.
    
    It only matters when you are on soundings. When you can see one of these 
    isolated islands it becomes piloting, whether you got there
    with a sextand, a cross-staff, dangling testicles, or a GPS.
    
    
    
    Rodney Myrvaagnes                   J36 Gjo/a
    
    "Religious wisdom is to wisdom as military music is to music."
    
    "What contemptible scoundrel stole the cork from my lunch?"  --  W. C Fields
    

       
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