Astro navigation

Astro Navigation

Many thanks for all the very helpful replies. The link to Tim's book also has information about a DVD. The detail seems to indicate that it's quite hands on so it may be worth looking at. It's something I am keen to know more about so I shall keep looking. It sounds like any one of the 3 books mentioned would be a good starter, at least for the basics.
 
nigel1 said:
As someone has pointed out, Bowditch is a free download, quite a lot of usefukl infomration and tables in that book.

If you want to go back to basics, ditch the reduction tables and use Nories tables, loads of log tables to play with. I can still reduce a sight using Nories quicker than our cadets using their calculators.

If you google around a bit you can find a 50 yr almanac somewhere, cannot remember the site, but it has no limits on use. I'll see if I can find it later
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Hi Nigel, you are evidently displaying a split personality with this post. Half the post refers to interweb thingy and the other half Nories Tables :D

Each to their own, of course, but I derive a certain pleasure from owning a book. Bowditch, for example, is a fascinating read, almost randomly turning to any page. I've never acquired the skill to do this with a .pdf download and I'm not planning to learn anytime soon.

After reading your post, I've just taken out of my library my 1963 New Revised Edition of Norie's. I've only used the Traverse Table so I'll take a look at how to reduce a sight. Thanks.
 
davidjackson said:
After reading your post, I've just taken out of my library my 1963 New Revised Edition of Norie's. I've only used the Traverse Table so I'll take a look at how to reduce a sight. Thanks.
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My edition is from the 70's, if it's similar in layout, the formula for Marc St Hilaire, Long By Chronometer and Ex Meridian sights are at the front of the book.
If your happy with logarithms then it's pretty straight forward.
Have fun
Cheers
Nigel
 
Absolutely the very best book I ever came across on this subject was the Admiralty Manual of Navigation Volume 2. Superbly clear descriptions and explanations, not only of the process of astro navigation (including the simplified methods) but also on the subject of nautical astronomy generally.

I have no idea if this is still in print. If it is, or can be had, it is well worth tracking down.
 
Litotes said:
Absolutely the very best book I ever came across on this subject was the Admiralty Manual of Navigation Volume 2. Superbly clear descriptions and explanations, not only of the process of astro navigation (including the simplified methods) but also on the subject of nautical astronomy generally.

I have no idea if this is still in print. If it is, or can be had, it is well worth tracking down.
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I'm pretty sure it's still in print, I have Vol 1 and 2, and a 1938 edition of volume 3, which delved into artificial horizons using buckets of mercury. There were chapters on working out course to steer to avoid torpedo's, I guess the navigator had to be pretty quick with his geometry.
 
I am glad that someone else thinks that Mary Blewitt's book is not that good. When I was learning astro everyone swore that Blewitt's book was the best thing since sliced proverbial. I tried and tried but never got on with it too much.

I haven't seen Tim's book, but I can tell you that Tom Cunliffe's book is very very good. It has a permanent place on the boat so that I can revise from time to time.
 
Litotes said:
Absolutely the very best book I ever came across on this subject was the Admiralty Manual of Navigation Volume 2. Superbly clear descriptions and explanations, not only of the process of astro navigation (including the simplified methods) but also on the subject of nautical astronomy generally.

I have no idea if this is still in print. If it is, or can be had, it is well worth tracking down.
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Its still in print however the older editions are better as much of the newer ones are based on using the navy's navpac software which most people don't have.
 
emandvee44 said:
a couple of digital watches will do very well, provided you get a reliable time signal, and take time;) to calibrate them.
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A couple of watches will be worse than one watch. Get three, five, or one so that you always have a proper vote as to which are incorrect!
 
I have a couple of these books and the one thing I can definitely say is that they are all useless on their own. Even with all the kit this is pretty dry subject material but if you only have the book then you won't be able to do any of the practical bits and it will get very very boring very quickly.
 
wadget said:
Its still in print however the older editions are better as much of the newer ones are based on using the navy's navpac software which most people don't have.
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Thanks. I might look in to the possibility of getting a new "old" edition - mostly for the interest and pleasure of owning such a lucid exposition of the whole subject. Many years ago I lent my copy, along with my air navigation tables, to a "fast track" yacht master who was planning a transatlantic trip. Sadly, he never returned them. Whether he made the trip or not I don't know.

Buckets of mercury are not necessary. If the OP gets a sextant, a decent book and the right tables and almanac, much can be achieved with a washing up bowl of water with a thin film of cooking oil on top. Bring the image down on to itself and halve the altitude. This is best done whilst lying on one's stomach. Learning to handle the sextant, identify and correct (or adjust for) errors etc. is just as important as learning to work out and plot the sight.
 
The best of the bunch, for me, is Wilkes - 'Ocean navigator' available here at a silly price :

http://www.abebooks.co.uk/servlet/SearchResults?an=wilkes&bt.x=0&bt.y=0&sts=t&tn=ocean+navigator

He explains Traverse Tables in a way that my non-mathematical brain can grasp.
Tom C and Mary Blewett do not even mention them and the Admiralty's manual's explanation is not as easy to follow.

In defence of Mary B, her book is now over 70 years old and teaching / printing have come a long way since she set out to simplify the subject. Her thoughts on position selection and systematic errors are well worth reading.

Tom C's 'Ocean Sailing' has a basic and common mistake describing 'composite tracks' and it surprises me that this has never been corrected. This is perhaps minor as the rest of the book is clear, humourous and worth its weight on board.

All in all, I don't think any one book / author covers everything which is my excuse for having at least ten books on the subject on my shelves ...........

One that was lent out and not returned - Langley Price / Ouvrey - will not be replaced as they manage to make a very dry subject even drier, this is where TC's humour and ease of reading give him a big plus.

stephenh
 
I turned to Cunliffe's book after not getting very far with Francois Meyrier's "Astro Navigation Made Easy". I found it useful, but the bit on plotting position lines leaves a lot to be desired and it wasn't until I had help from the cognoscenti on this forum that I got the hang of it.
 
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