# NavList:

## A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding

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From: Jim Manzari
Date: 1998 Sep 28, 14:12 EDT

```Russell Sher wrote:
>
> Hi - I think that the nav. list seems to be on the blink (or just quiet??)
>
> So - what was the answer the the noon sight question ( two suggestions below
> from Joe and myself...)
Russell and Joe,
I was wanting to see if more answers might come in.  Nothing...so it
looks like the winner is Joe Shields.  The ship is moving on a nearly
south to north line.  The relative motion -- ship + sun -- causes the
sun to reach its highest altitude _before_ local apparent noon.  The
clue to the question is the 16kts ship speed.  Had it been a slower
vessel, say a yacht sailing at 5kts, this effect would be very
difficult, indeed, to detect.
Here's a bit of the conversation between the ship masters and a
further twist on the subject of noon sights...comments welcome.
--------
...I consider myself to be a reasonably experienced (celestial)
navigator, but I am puzzled by the problem.  The only explanation that
I can think of, is that you were on a heading directly opposite to the
sun (I confess that I am not familiar with the geography of the area
between Mauretania and the Schedlt) and thus the sun appeared to be
decreasing in height but still approaching your meridian.
And now, I have to add a bit of my own opinion regarding the noon sun
The noon sun shot is overrated.    It's beauty lies in the simplicity
of the calculations required to obtain one's latitude, but that is
where it ends.    One can easily take a few quick observations at
"around" noon hour, reduce the sight as normal and plot the resultant
east-west LOP on your chart to obtain your latitude.    This method is
particularly useful at high latitudes where the trajectory of the sun's
passage tends to be fairly flat and determining the exact moment at
which the sun reaches its maximum height can be somewhat subjective.
In the winter time here in Iqaluit, I have sat outside, freezing my
tail off, for up to 45 minutes, waiting for the sun to reach its
maximum height of 3 degrees above the horizon.
Even in the mid-latitudes, I have seen people up on deck taking
observation after observation, trying to determine the exact moment of
meridian passage, and even after all of that, there is no guarantee of
a satisfactory result; I have rarely seen two people obtain the same
numbers.    I am not suggesting  that the noon sun shot should be
discarded - I still like to perform the operation - but it is not the
be all and end all.
Ok, allow me to put on my bullet-proof suit....fire away folks!
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