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Jim,
My best answer to that is that LAN is the easiest sun LOP to compute.
Since you have less steps, there are less chances of making an error
that will carry over to your final answer. Many people equate the fact
that LAN gives you a line of latitude with that making t more valuable.
In actual practice it is better to shoot several sunlines and advance
them to a common time to give you Lat and Long. Latitude alone is only
extremely valuable if you plan to finish your voyage by latitude sailing
rather than sailing a more direct course to your destination. I mean no
disrespect to the current author of Dutton's (CDR Thomas Cutler) or any
other Naval Officer, but I feel that while Dutton's is a great resource
there are many more knowledgeable celestial navigators available outside
the officer ranks of the US Navy including many of the members of this
list.

-----Original Message-----
From: Navigation Mailing List
[mailto:NAVIGATION-L@LISTSERV.WEBKAHUNA.COM] On Behalf Of Jim Thompson
Sent: Sunday, January 25, 2004 18:31
To: NAVIGATION-L@LISTSERV.WEBKAHUNA.COM
Subject: Re: Latitude AND Longitude by Noon Sun

-----Original Message-----
From: Navigation Mailing List
[mailto:NAVIGATION-L@LISTSERV.WEBKAHUNA.COM]On
Behalf Of Stacy Hanna

Jim, I'm not entirely sure what you are asking. I'm not sure if you are
questioning why LAN should be observed or why the Navy is doing
celestial at
all. (snipped)

Stacy: thank you for your very illuminating message on the current day's
work at sea instruction in the US Navy, however it does not answer my
poorly-framed question.  I was just pointing out the current Dutton's
emphasis on LAN observations, within the context of all the discussion
we
have been seeing about the risk of error in deriving certain information
from a noon sun sight.  This thread is splitting into two themes: (1)
current CN practice at sea, and (2) discussion about the fine points of
noon
sights, particularly error due to difficulty in determining the precise
point of LAN.  Recall that I am still finishing up my CN course, not an
experienced celestial navigator.

I made that quote because of the phrase, "it (noon sun sight) can
usually be
relied upon to yield the most dependable celestial LOP of the day".
Given
the concerns expressed about errors in determining LAN, I am still not
sure
that I understand why Dutton's uses the term, "dependable"?

-----Original Message-----
From: Navigation Mailing List
[mailto:NAVIGATION-L@LISTSERV.WEBKAHUNA.COM]
On Behalf Of Jim Thompson

From Dutton's, 15th edition (new this month): "...the LAN observation is
extremely important in navigation, chiefly because it can usually be
relied
upon to yield the most dependable celestial LOP of the day.  The Sun
should
be observed at LAN as a matter of routine aboard every vessel.".  Why do
they make that statement in 2004? Especially naval authors writing for
beginners in the modern digital navy.

Jim Thompson
jim2@jimthompson.net
www.jimthompson.net
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