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Old 08-02-2015, 08:48   #1
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Materials for learning celestial navigation in an emergency

What materials should be part of an emergency celestial navigation kit that would allow anyone to chart a current position without any prior knowledge about celestial navigation? For example if all electronics fail or for fun on a ling passage.

Is there a book that explains the practical aspects and the steps very well?
I already bought a used Simek III sextant. Do I need to have it adjusted by someone?

Thanks!
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Old 08-02-2015, 09:07   #2
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Re: Materials for learning celestial navigation in an emergency

Sextant for fun is good...I don't believe it is realistic to get good fixes the first time you try. Small GPS and extra batteries is more reliable...


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Old 08-02-2015, 16:25   #3
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Re: Materials for learning celestial navigation in an emergency

Use whatever Redford used. And don't forget to set the raft on fire.
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Old 08-02-2015, 17:05   #4
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Re: Materials for learning celestial navigation in an emergency

If you're mathematically inclined, the Nautical Almanac has directions for obtaining a position, without the use of additional books. My wife, who is mentally what I am not, accurately reduced a moon shot using such directions, but filled two sheets of notebook paper with tiny scrawls doing so. I used the H.O. 229 tables and achieved the same result. It takes much time to get proficient with a sextant--I would recommend using it extensively even while your electronics are working so that you won't NEED to learn anything new and complicated in the event of a calamity. Still, to answer your question, a sextant, a nautical almanac, and accurate time are a bare minimum. You can substitute tables for clearing the Lunar Distance for a timepiece, but learning THAT is something best left to the likes of my wife.
There are books, and no doubt online information on how to adjust your sextant. I have adjusted mine so there is never any index error--one less calculation to fret about.
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Old 08-02-2015, 17:51   #5
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Re: Materials for learning celestial navigation in an emergency

Tomminy,

The emergency use instructions give a location within 5 to 10 miles without tables or anything else and with prior experience.
Of course I havent tried it as I live in the 21st century, but you can download the free ebook and print it off for when you need it [i thought it was free... But only if u buy the sextant!]
https://www.starpath.com/catalog/books/1840psb.htm

You can plot your location with any old atlas, or even a pilot chart etc, so you dont even need a proper paper chart of your area.

You wont be spot on. But you should be able to navigate yourself to a coast where you can VHF -- ooops, no electricity -- smoke signal for help... Or just follow some ship that looks like he is going into port. As long as he diesnt crash you are fine.



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Old 09-02-2015, 09:39   #6
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Re: Materials for learning celestial navigation in an emergency

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Originally Posted by tominny View Post
What materials should be part of an emergency celestial navigation kit that would allow anyone to chart a current position without any prior knowledge about celestial navigation? For example if all electronics fail or for fun on a ling passage.

Is there a book that explains the practical aspects and the steps very well?
I already bought a used Simek III sextant. Do I need to have it adjusted by someone?

Thanks!

There are a lot of books that explains the practical aspects and the steps to use a sextant for celestial navigation.


No. You don't need to make an adjustment on a sextant. That's like taking your magnifying glass for an adjustment.


More than fun, learning to work the sextant is opening a door to history; and THAT navigation is an adventure in itself.
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Old 09-02-2015, 09:53   #7
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Re: Materials for learning celestial navigation in an emergency

You're never really lost. You'll always have a rough idea of where you are.

Once the electronics fail begin doing DR and record it every hour.

You must have an accurate watch set to GMT.

You need The Nautical Almanac for the Sun only, or the Planets and Stars, and HO-249. Working with the Sun is easiest. The Nautical Almanac for the Sun is the minimum you need. The stars are nice to navigate by but they're harder to spot and you have to work much faster.

Get it all here;

The Nautical Almanac


Buy a calculator and follow the formulas at the link below, particularly the one about Determine Latitude from Noon Sight and Determine Local Apparent Noon using GHA. If you can determine LAN (Local Apparent Noon) you can get a rough approximation of your Longitude within 30 miles or so and a very good determination of Latitude.

Get it here;

Formulas

Without HO-249 you can still do a sight reduction using your calculator. Just follow the Formula page at the link above.

If you don't have The Nautical Almanac, at a minimum you need TABLE 4. — GHA and Declination of the Sun for the Years 1981--2016

Get it here;

http://thenauticalalmanac.com/GHA%20...0to%202016.pdf

But....you really have to be careful when using Table 4. It's somewhat difficult to learn how to use.


Pray for clear skies.
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Old 09-02-2015, 09:57   #8
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Re: Materials for learning celestial navigation in an emergency

everyone in my humble opinion should when doing ocean crossings known how to simple do a sun run sun ,or a meridian passage, a sextant only gives you altitude, its the simple maths that a child could do, the only problem is remembering the sequence,to start with forget planets and stars master the sun first its the biggest star and easily recognisable, all you need is a nautical almanac and the sight reduction tables AP3270 volume111 and a cheep digital watch for the critical time and away you go, to help you understand what its all about ask me? but much better buy a small ocean sailing book by Tom cunliffe costs maby 10 pounds english its so simple its like having a tutor with you 24/7, it will enhance your knowledge immensely trust me, when these wonderful gps go down you will understand these humble words. TS


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Old 09-02-2015, 10:27   #9
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Re: Materials for learning celestial navigation in an emergency

IIRC, David Burch wrote a great book called Emergency Navigation. Worth the read, good for a ditch bag, too.
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Old 09-02-2015, 14:44   #10
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Re: Materials for learning celestial navigation in an emergency

Twenty some years ago I learned how to do a sun sight one time. It was somewhere within 50 miles. I only did it once. So somewhere in my brain, I have stored, that information. I have just forgotten where I put it. mac
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Old 09-02-2015, 19:03   #11
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Re: Materials for learning celestial navigation in an emergency

You want:

- an accurate Casio watch, a.k.a a chronometer, ;-)
- a sextant,
- a source explaining what you are looking for,
- a pencil & paper, for plotting,

When you understand what you are doing it and why, is an easy task. However, most books & courses I have seen made an easy thing difficult to understand.

If I were to take only one book, it would be the one by Bennet. (Buyer Beware: no longer published, and so you want an almanac too now).

b.
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Old 09-02-2015, 19:13   #12
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Re: Materials for learning celestial navigation in an emergency

I think an emergency situation is probably the wrong time to learn how to do something but I guess it would be better than nothing. My extent of celestial navigation is identifying the north star. I keep a few gps devices though, just in case one fraps out.
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Old 24-02-2015, 14:10   #13
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Re: Materials for learning celestial navigation in an emergency

Buy, read and memorize the wonderful little book:
Celestial Navigation for Yachtsmen
by Mary Blewitt
It includes all you will ever need to know in a perfectly clear and concise presentation.
IMHO the best of all celestial navigation books (and I have several and have looked at many more).

But, as said above, several handheld GPS units with spare batteries will serve you much better in emergency (once again, MHO).
Do not pay attention to latter day doomsayers that warn against GPS system being suddenly closed, ( And if it will be closed, you will probably be better at sea anyway...)
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Old 24-02-2015, 18:06   #14
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Re: Materials for learning celestial navigation in an emergency

William F. Buckley produced a DVD many years ago in which he went through the step by step process for reducing a sun sight. The DVD is still available on line. I have one myself. It is titled, "Celestial Navigation Simplified. Go to bennettemarine.com. Highly recommended.
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Old 24-02-2015, 18:44   #15
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Re: Materials for learning celestial navigation in an emergency

Jeez, I don't know, I studied nautical science in college. Celestial navigation really isn't very easy. I think even I would need Bowditch or Howse as a reference to refresh my brain. How do you feel about dead reckoning? It would be my go to.
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