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    Re: Sextant accuracy with short distance to horizon
    From: Yves Arrouye
    Date: 2001 Jun 28, 11:27 PM

    > I very much like your explanation why one should add the wave
    > hight to the
    > height of eye when observing from a wave top. Only for one 'but':
    > your line of sight is tangent to the horizon, so for all
    > practical purposes
    > (wavelength assumed small w.r.t. curvature of earth) the
    > horizon is formed by
    > wave crests. There's no way of seeing a trough at the horizon
    > because there is
    > a crest relatively close in front of it. So both observer and
    > horizon are
    > raised by approximately the same distance (say, the
    > significant wave height),
    > and the dip should be calculated for the elevation of the
    > observer above  this
    > raised horizontal level.
    
    BTW this is what Bruce Bauer says in his Sextant Handbook. He also says that
    on the bridge of a large ship, you want to correct for that, as only your
    horizon seems raised by the waves.
    
    YA
    

       
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