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    Re: Dip uncertainty
    From: Alexandre Eremenko
    Date: 2004 Dec 6, 10:40 -0500

    Dear Bruce and George,
    I tend to accept George's explanation
    (and most importantly the conclusion that dip uncertainty
    should INCREASE with the observer's height).
    The longer path the light ray has to go in the atmosphere
    between your eye and the horizon leads to larger dip uncertainty.
    The real problem with small boats should be that you usually
    do not see the horizon because of the waves.
    On Mon, 6 Dec 2004, George Huxtable wrote:
    > And what dip affects observations from that vessel? The standard dip, from
    > the almanac, is doubled. The anomalous part of the dip will be, initially,
    > the same as affected me at 2.8 miles, but now the light goes on, still
    > close (from 6 to 24 ft) to the sea surface, so there's extra curvature
    > added as a result of that additional 2.8 miles of its path.

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