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Jeremy wrote-

 For a larger merchant ship (>100 Meters)  good
| conditions consist of a sky that shows the bodies and, equally
importantly,  a
| crisp horizon.  There have been many times when the sky above is very
clear and
| many stars are visible, only to have a fuzzy horizon that leads to
abnormally
| high errors.

===============

This could be a case where Jeremy's lofty perch, up on the bridge, is
actually working against him, and where those of us in small crafr have an
advantage. From 100 feet up, the horizon is nearly 12 miles distant, so a
bit of haze in the air could easily spoil its clarity. I don't know the
height of Jeremy's working-deck level, but if he could descend to 50 feet,
that reduces the horizon distance to 8 miles, which could well make all the
difference. From the cockpit of my own small boat, the horizon is little
more than 3 miles off.

Lecky tells of a time when he needed a good position entering the Plate
estuary, but his horizon was too hazy to take a sight. So he had the
accommodation ladder lowered over the side, and took an altitude from its
bottom step, just above sea level. I doubt if Jeremy would be able to
persuade his "old man" to agree to that, however.

George.

contact George Huxtable at george@huxtable.u-net.com
or at +44 1865 820222 (from UK, 01865 820222)
or at 1 Sandy Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK.


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