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Fred,

You wrote:

> On Dec 6, 2004, at 9:16 AM, Trevor J. Kenchington wrote:
>
>> With anything of a sea running, of course, the uncertainties in the
>> horizon and in the true height of eye that are produced by wave action
>> are likely to overwhelm anomalies in dip for an observer close to the
>> sea surface (except perhaps under the most extreme conditions).
>>
>
> Bruce Bauer had exactly the opposite take on this.


Can you provide a page reference? I have re-read his section on
rough-weather techniques and I can't find that he mentioned height of
eye. Or do you mean his comment that a navigator on a ship's bridge
should allow for wave height when applying the dip correction whereas a
yachtsman should not?

The latter is true, so far as I can tell, but I'm confidant that the
allowance can be more precise than the yachtsman's attempt to guess how
high his eye was, at the instant of contact between Sun's lower limb and
  the wave crest on the horizon, particularly since the rate of change
in the dip correction falls off very markedly as height of eye increases
(such that it is less necessary for the big-ship navigator to know his
exact height of eye).


Trevor Kenchington


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Trevor J. Kenchington PhD                         Gadus@iStar.ca
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