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Jeremy, you wrote:
"Well I found my first lunar, and it will be tricky.  Here's the data that I
have.

GMT Date is 26 January 1999.  GMT of the sight was about 2220.  Dip
correction is -7.7' of arc.  The lunar was at evening twilight and a near
limb observation between Jupiter and the Moon was taken.  The sextant LD is
68deg 19.4'  IC is 0.0'.  An upper limb altitude of the moon was taken HS is
66 deg 09.3'  The Hs of Jupiter is 45 deg 22.3.

Here's the rub:  I have no idea where I was other then to say I was probably
somewhere in the Eastern Caribbean.  Best guess is about 20 deg North
Latitude and 70 degrees West Longitude."

Having a good DR position is convenient but not necessary when it comes to
clearing a lunar. Of course if you want to assess the accuracy of the sight,
then you want the actual position and correct GMT as nearly as possible. You
can figure out where you are, more or less, by trial and error from your
sight data. Go to the calculator on my web site, set the GMT of the sight to
22:19:30 and set your DR Lat to 14d 31'N and your DR Lon to 61d 38.1W. That
nearly matches your sights, lunar and altitudes, too. So assuming your
observations were good (and I would bet they were) you were probably about
30 miles west of Martinique. Does that fit your recollection?

Now as it happens, this is yet another one of this miraculous lunar sights
where you can do the clearing without using any spherical trig. If we take
the pre-cleared altitudes and distance (the altitudes of the objects'
centers and the center-to-center lunar distance) and add them up, we get
nearly 180 degrees. So adjust the Moon's altitude higher by about 24 minutes
of arc and then work it AS IF they were exactly opposite each other in the
sky.

 -FER



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