Bob,

Thanks for the great online references!

I apologize for nit picking,.

The Noon Site is the best and easiest single sextant reading for
elementary navigation.

Yes, the Local Apparent Noon sight is one of the most straightforward
sight reductions, and probably the most commonly done, because the sun
is such an easy body to see, and the only body generally useful in the
daytime.

It will give Lat and Long.

Well, actually any single sight by itself will only give a line of
position that circles the globe.  An untimed sight taken at or near
local noon will provide a line of position that runs east-and-west,
called a meridian, and will very nicely give you your Latitude.  In the
days of old before precise time became available via radio the best
approach was to advance along your Dead Reckoning Track one or two sun
sights from much earlier in the morning.  That would give a reasonable
cross line on your meridian, and within the precision allowed by your
dead reckoning advance and assorted instrument and personal inaccuracies
-- you knew where you were.  Clearly, you had to know approximately
where you were to run a Dead Reckoning track, but the conscientious
navigator of old worked pretty hard to do just that.  Such imprecision
is dandy for the trackless deep blue passages, and when practiced by the
masters of old (Nathaniel Bowdich high on that list) gave some
incredible landfalls.  More commonly it was quite imprecise and second
only to bad luck is blamed for any number of terrible wrecks.

Determining Longitude by celestial means requires precise information
about the time of the celestial events we are using.  Virtually all the
procedures we think of as celestial navigation were developed during the
time when mechanical chronometers provided the mariner or airman with
pretty good timekeeping.  For example an error of one minute of time
when tracking along the equator translates into one nautical mile of
distance.  This error shrinks to millimeters when one is in the
unfortunate position of being within arms length of the North or South
Pole.  My own experience maintaining and using Navy chronometers
mumblemany years ago indicated that if you wound them between 1100 and
1115Z every day, and got the radio shack to send up a time tick, logged
all three errors at that time, you could plot each timepieces errors,
advance whatever trends you found, average the three results and still
be uncertain what time it was.  You then call the radio shack back for a
new time tick, start your stopwatch from that and proceed with taking
your celestial sights.

If you take more than one sight, or worse still you have some officers
helping/practicing, and the boat is moving, etc. you can't stop the
stopwatch for each one, thus you have to read off the moving second hand
on the watch face, and getting precision much beyond a whole second is
tough.  The horizon is never perfectly clear, boat motion, breathing and
heartbeat effects conspire to jiggle even the best images, and plain
human errors creep in to compound the imprecision in time, and yes, even
the best of us who practiced all the time sometimes got triangles a mile
or more across.  We also sometimes got four, five or six lines to cross
perfectly on our chart or plotting sheet.  I got a seven once.  Of
course the charts we use for the deep blue are pretty large scale, so a
pencil dot still covers a sizable patch.

All this imprecision is fine for the great open waters, where
coincidentally the only things one has to navigate from are celestial
bodies.  If some identifiable land is visible, even if only on radar or
with the fathometer, it is much easier and far more precise to use
distances and bearings to determine your position.

Then along came Loran, and finally GPS.  Now the time is automatically
measured in gazillionths of a second, and incredibly precise position
finding has become mundane.  This is available for well under a hundred
bucks and is useful wherever satellites are visible.  Human error is
removed from the observations and the calculations, and the devices are
cram packed with ancillary features like instant bearing and distance to
the nearest Krispy Kreme shop (that's on the police model).

I guess that what I am trying to say to anybody about to invest time and
resources in celestial navigation is that you should treat it as a
hobby.  Kinda like stamp collecting.  The number of times that you will
need to use it in your real life boating is similar to the number of
times a stamp collector uses his collection to mail letters.  Celestial
is not particularly useful near land because of the aforementioned
imprecision and because useful horizons are obscured.  Artificial
horizons used to be a large pan of mercury, then water -- neither useful
on a moving boat.  Aircraft sextants used a bubble in place of the
horizon sight, but they are particularly hard to find nowadays, and
weren't particularly precise anyway.

Unless you practice these arcane skills they will be unreliable in the
unlikely event that you need to make an extended blue water crossing and
require precise navigation to make something like a mid-ocean island
landfall.  Why do  without electronic systems which are so cheap that
multiply redundant equipment and a bag of batteries is easily within
reach of even the most modest boat budget.

Today, a sextant is a toy, and celestial navigation at best an arcane
skill, and for most of us, an historically fascinating obsolete skill.
By all means, get as fancy a toy as you fancy, and play with your toys
as much as you can.  Playing is good for us all.

Using a sextant to take vertical measurements of items of known height
can be used to determine a range from said object, but my radar already
does that so much more easilly, and range estimating binoculars are
already on the market.  Shooters use laser rangefinders that would also
work at appropriate shorter ranges.

Plotting the results of horizontal bearings taken with the sextant is
usually done with a very cumbersom three armed protractor or a
scientific/engineering calculator, and the term handy would never occur
to one using these techniques.

If you want to get a similar cool toy that will help with pilotage (near
coastal navigation, using bearings and such), get a binocular with the
compass built in, or one of the older sighting compasses.  These will
allow you to take bearings on the landmarks you see and plot the Lines
of Sight back on your paper charts.  Particularly useful where there are
no buoys or daymarks, for confirming an anchorage or monitoring an
anchor watch.

Sorry for the extended rant, I kinka get wound up about investing so
much effort to learn and practice this really cool technology and like
all such things, a little sad when it becomes obsolete.

Gary Bell

-----Original Message-----
From:  Gary Bell

I guess that what I am trying to say to anybody about to invest time and
resources in celestial navigation is that you should treat it as a
hobby.

REPLY
Of course it's a hobby, and so is boating!
Boating is not a matter of life and death; it's much more important than
that!
It's a hobby and boats are big guy's toys!  <VBG>

Gary wrote
Why do without electronic systems which are so cheap that multiply
redundant equipment and a bag of batteries is easily within reach of
even the most modest boat budget.

REPLY
Because it's there; the challenge I mean.  No challenge = no fun.
Practically speaking if you want to go from A to B take a plane. Its
faster, cheaper and more convenient.
After all no sane person would buy a hole in the water into which they
then add more and more money, with a guaranteed negative return on
investment. Not to mention which, active participation definitely incurs
risks not covered by insurance. See thread on cruising in PNW, S Florida
or any other area you care to mention. Locals with in-depth knowledge
have finally revealed the unvarnished truth about the horrendous dangers
to be found. Boat eating whirlpools, man eating bears and air lift
capable mosquitoes. Sheesh!

Now if you will excuse me I will put my sextant back up on the shelf
alongside my Viking era sun stone compass and go out with my muzzle
loading gun for some target practice.
It finally stopped snowing so I can wear my buckskin jacket without
getting it soaked. <VBG>

Arild