Want to Learn Celestial Navigation

[gates_cliff]

I want to learn Celestial Navigation. Can it be self taught from a book or do I need to take a class?

[Jeff and Sarah]

It can be self taught, but it is pretty complex. If you have an opportunity to take a class you should jump on it. It's a lot of fun though. We had to take 4 semesters of it at Texas Maritime Academy and I loved every minute of it.

OK that's a lie- I loved every minute of the concept, but shooting star lines near the Arctic Circle in the summer months means you are up very late for night stars and then very early a few hours later for morning stars. That wasn't so great.

Jeff

[Bruce Dart]

The Unlikely Boat Builder has a good primer on celestial navigation on his blog. You can find it here:

http://www.unlikelyboatbuilder.com/2010 ... ail boat.

[WaywardWind]

Celestial navigation is simple enough to learn off a crib card. (Does Davis still make 'em?)

It gets lots more complicated when one tries to use spherical geometry rather than planer geometry for about a meter greater accuracy at about a hundred miles out.

It gets REALLY complicated when one wants to use lunar angles to tell time rather than a quartz Timex.

In the days when celestial nav was the order of the day, long distance ships set their course for something a bit north or south of their distination, so when they finally spotted land, they KNEW which way to turn to get to where they wanted to go.

THE secret to celestial nav is not the theory nor the math, but rather the practice, practice, practice, practice to get good sights on a boat rolling at sea. I've seen people take upwards of two hours to figure out celestially that they were within 50 miles of where the gps showed immediately. I've also seen 5 days at sea without sun.

Best use of a sextant these days is as a decoration over a fireplace mantle.

Mary Blewitt's book is probably the best available for the person who wants to learn it by themself just for old times sake.

BTW, the Bris is an interesting way of making accurate sextants from microscope slides. Sven Yrvind used one to round Cape Horn in his micro-sized sailboat. The angles on the Bris are fixed, so one has to wait for the sun to get to the right position, THEN the time is noted. I seem to recall the Bris can be used something like eight or sixteen times a day. It fits in a 35mm film cartridge, and costs near nothing to make.

[Jeff and Sarah]

Sun sights and Star sights are a little different and not quite interchangeable. Since the sun is a single celestial body you need to advance your sun line of position (LOP) along your plotted course line to obtain a DR track. Star sights will allow you to take several LOPs that will cross at your exact position (once you are handy with a sextant- operator error here will give you more of an 'exact area that you are somewhere within'.

The sun is also used to obtain Local Apparent Noon (LAN) to provide your one daily chance to determine latitude- that was pretty high tech stuff when it was created!

[John Stone]

You can certainly teach yourself celestial navigation and there is no reason not to know how. It more than accurate enough for the job. I learned it as a young skipper when I was 17. I plan to make it the centerpiece of my off-shore navigation system when I complete the rebuild of my boat.

I still have the book I used to learn how--"Self-Taught Navigation" by Robert Y. Kittredge. It's probably out of print but I bet you can find it used it on www.alibris.com. It is straight forward and simple step by step using HO 249.

You might try visiting http://www.celestaire.com They have a lot of useful info for celestial navigators.

Don't let anyone tell you its a waste of your time. There are few things as rewarding as casting your eye to the heavens to find out where you are. Nothing will get you closer to the experiences of the pre GPS off shore sailors. And you can still carry a GPS when you lose your nerve . . . .


Best of luck.

[ckreitlein]

I am teaching a class on celestial navigation at Pensacola State College in early Feb. I will be using the manual that I wrote as the text book - Simple Celestial, Navigation by the Heavens Made Easy. Check the webside - www.globizon.com - for the manual. It is cheap and I think (naturally) the best one around for learning celestial navigation.

[Oswego John]

To all,

It never ceases to amaze me of the talent and abilities of the CDSOA members.

I bet that hidden way back there, concealed by natural modesty, are some members whose talents would knock our socks off if revealed.

What a group,
O J

[WaywardWind]

I once knew a guy who raised a few sheep on a small former farm in Illinois. He cut the wool, saving until he had enough. He then washed the wool and carded it. Next, he dyed the wool the color he wanted (he bought the dyes my mail) in a kettle (which he owned) in his back yard over a wood fire (because he didn't want to spend the money for a propane burner for such a small job). Then he wove the wool in his dining room on a loom he built himself in his basement into a long piece of goods. He then cut the wool to shape and sewed himself a sport coat (using lining from JC Penney) on a treddle sewing machine made when his grandmother was a small girl.

The sport coat looked nice, if a little unusual, and he was justifiably proud of his work.

[John Vigor]

Celestial navigation is simple enough to learn off a crib card. (Does Davis still make 'em?)


Mary Blewitt's book is probably the best available for the person who wants to learn it by themself just for old times sake.

I agree with WaywardWind. Celestial navigation in its simplest form is very easy, the hardest part is getting decent sights from a small boat bobbing on a big ocean. But that comes quite quickly with practice.

I taught myself from Mary Blewitt's book, Celestial Navigation for Yachtsmen. It's a very small book with lots of illustrations and examples. It's a marvelous starter book -- it got me across the Atlantic twice -- and you can either stop there or go on to become a much more expert sextant navigator, which probably isn't necessary in these days of GPS. Mary will get you within a few miles of your destination, and common sense will do the rest.

Cheers,

John V.

[Jeff and Sarah]

John,
Your avatar had me swatting at my screen. It seemed odd to see bugs that small out in weather this cold!
Thanks for the fingerprints,
Jeff

[John Vigor]

Jeff, that's not an avatar, that's a baby cockroach. My computer guy warned me I had a bug, but I didn't realize he meant it literally. He says you shouldn't worry. It won't affect your monitor until it grows a little bigger and bursts its way out. You got a couple of weeks, at least. Oh, and sorry about the fingerprints. Wear gloves next time.

Cheers and complaints of the season to you.

John V.

[fenixrises]

Hi all,

If you can find it John Letcher's Self-Contained Celestial Navigation with H.O.208 is a great all around nav text. His book contains the complete H.O.208 tables. They are only 85 pages and no longer in print from the gov. His book is smaller than one of the H.O.249 tables and can be used for any celestial body for sight reduction.

The book also contains numerous tips on money saving ideas, including converting a surplus air nav sextent to marine use and how to use simple lined note book paper for plotting sheets.

On a passage from CA to Hawaii back in the 60's John discovered a new method for doing lunars to determine time. He was a math major at CIT back then.

I used this book along with the nautical almanac and a used sextant bought from a ship breaker in Taiwan, to sail from Taiwan to the Marshalls in 1985.

Take care,
Fred

[gates_cliff]

I am both encouraged and awed by all these responses. As JO said, I think we would be amazed at the accomplishments reflected here if modesty didn't prevail.

I'm 66, nearly 67, have sailed on the Chesapeake for years on a variety of boats, have crewed a couple of times offshore but doubt I'll ever skipper my own boat across the Atlantic. Although I'd surely love to. So, I doubt I'll ever have a real need to use celestial navigation but it's something I'd like to learn. I'm a retired high school history teacher and have realized my knowledge is so superficial so I guess I just enjoy learning new stuff, I'd probably be better served learning something marketable (I still work for a living, a teacher's retirement in the Washington DC are doesn't go far).

Thank you again.

[Jim Davis]

Another good book for self taught is "Sky and Sextant" by John Budlong. It too is out of print, but available from the used booksellers. It is a good text and uses the Nautical Almanac and 249 as the primary publications for sight reduction. While this is not they one I learned from, it is one that I lend to friends who are interested.

http://www.amazon.com/Sky-Sextant-Pract ... 0442211368

As a disclaimer I will say I have no financial interest, but am a practicing celestial navigator.