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    Re: How much resolution is enough?
    From: Bill B
    Date: 2014 Dec 17, 15:10 -0500

    On 12/17/2014 2:51 PM, Greg Licfi wrote:
    > Also if I take multiple sights, only at say, at the crest of a
    > wave -
    > - do I figure wave height into my eye height error?
    
    You do not need to add wave height to usual height of eye for dip. When
    you are at the top of the wave your horizon is the tops of other waves
    (hopefully not a predictable extreme nearby), so they cancel out--more
    or less.
    
    Reducing the argument to the absurd, if you were in the trough of a 30-
    foot wave your horizon would almost certainly be the top of the next
    wave. This is why we shoot from the tops.
    
    As an analogy, imagine yourself watching sunset from a mountain top
    using another mountain top of the same elevation as your horizon. Sunset
    should be on time. Now imagine watching the same sunset from a valley
    with the mountain between you and the sun. The observed "sunset" will be
    much earlier than predicted.
    
    

       
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