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Robert wrote:

> One practical way to take 'these errors' into account has brought up
> by George only to be dismissed. When a known risk exists in the
> vicinity, then assume the position (fix if you prefer, or 'probable
> position' or any other nomenclature of choice) lies along the LOP at
> the closest point to the danger, rather than the centre of the
> enclosing LOPs. I would contend that this is simple common sense.

There I would disagree. The very fact that the ellipse, external or external
cocked-hat "fix" or "EP" exists testifies to the uncertainty of the LOP's;
be it plus/minus 2 nm or 5 nm per LOP/COP in the practitioner's estimation.
Therefore to be safe, the prudent navigator would allow for the possibility
that a given LOP may be 2nm, 5nm, or whatever closer to the danger than the
LOP itself would indicate.  Factor in George's assessment of a 25% chance of
internal and other texts' statements that true position may be outside the
cocked hat formed by the LOP's.

Being prudent, better to stay well outside the "smudge" produced from two or
more LOP's plus a "fudge" or "Jesus" factor.  Slop pool is still just slop
pool at the end of the day.  The goal is for the day to end well--not
swimming as the sea is neither a swimming pool or pool table. :-)

Bottom line, don't try to navigate Hell's Gate (Peter's magnificent photo's
from Tasmania if I recall) with cel nav only unless you are itching for a
"Darwin Award" nomination. 

Bill


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