Want to Learn Celestial Navigation

[Forrest]

The US Power Squadron has a class from time to time. I'm taking the 1st of a 2 semester celestial navigation class. The teachers are excellent, the subject fascinating, the price is a steal.

I can only speak for myself - there is NO WAY I could learn this on my own. Sea time, altitude corrections, celestial coordinates, celestial LOP, meridian transit - a LOT of content.

Whether you learn it on your own or take a class, it's great stuff to know !

[Dixon Hemphill]

Rather than trying to locate "out-of-print" books on celestial navigation, CDSOA members might be wise to get a copy of Chris Kreitlein's "Simple Celestial Navigation by the Heavens Made Easy". I am no expert on the subject but I found his 101 page book to very well written. It presents the subject in terms, descriptions and graphs that really do make the subject of celestial navigation relatively easy.

[tartansailor]

I taught Celestial Navigation in the Power Squadron, and support what Forrest said. Incidentally the "Nautical Almanac Site Reduction Method" as taught by the Power Squadron requires only (1) reference: the Almanac. And once mastered then the "Calculator" method is a shoe in, but I use a log log slide rule when things get nasty.

Dick

[Rollergirl]

For your ZIP: 20751 DEALE, MD

Closest Squadrons

Distance: 11.7 Miles
Annapolis Sail & Power Squadron District: 5 Chartered: 1941 - Web Site
Contact: D/Lt Gretchen Cupples, S Phone: 410-268-3922
Email: gretchenlucia@aol.com
Centered around: ANNAPOLIS, MD 21403


Distance: 17.8 Miles
Miles River Sail & Power Squadron District: 5 Chartered: 1953
Contact: Cdr Peter E. A. Gregory, P
Email: tiderunner4ever@aol.com
Location: Eastern Shore of the Chesapeake Bay
Centered around: SAINT MICHAELS, MD 21663


Distance: 18.8 Miles
Kent Narrows Sail & Power Squadron District: 5 Chartered: 1993 - Web Site
Contact: P/C John H. Yeigh, AP Phone: 410-643-2106
Email: jyeigh@verizon.net
Location: Chester, Maryland
Centered around: CHESTER, MD 21619


Distance: 23.8 Miles
Patapsco River Power Squadron District: 5 Chartered: 1916 - Web Site
Contact: P/D/C John Brian Becker, AP Phone: 410-442-1230
Email: jbrianbecker@verizon.net
Location: Pasadena, MD
Centered around: PASADENA, MD 21123

[WaywardWind]

"use a log log slide rule when things get nasty"

If I may, all slide rules are based on the log scale. Some slide rules also have a log log scale(s). For multiply/divide, a log scale is used.

A caution. Slide rules are more or less accurate (depending on operator) to two digits, with the third digit an estimate, except for numbers to the left side of the rule (numbers between 1xxx and about 2.5xx) which are more or less accurate to the third digit, estimated to the fourth.

Much of celestial math goes to well more than three digits. Even a cheap calculator from the drug store goes 8 digits.

Slide rules have gone the way of the dodo bird, except circular slide rules can still be found out there for doing simple things like converting mph to knots, imperial gallons to US gallons to liters, etc.

I now own a fine, fine Picket slide rule (about 20 scales) I couldn't begin to afford when I was a freshman physics student. I bought the Picket at a yard sale for $1, complete with original case and 1953 instruction manual rolled up and stuffed under the belt loop on the case.

[Como No Cruising]

Aboard Como No we put the sextant in the box and stowed the Celesticomp several years ago when we discovered that, indeed, GPS was accurate and here to stay. We still keep all on board, just in case, a point that was brought home to us when lightning took out all our electronics when we were in the Rio Dulce river. Had to sail back to Texas for repairs without electronics or autopilot. Wow, you can get by with just the old standbys. Neither the Sextant nor the wind vane were affected by the lighttning.

Shortly after the lightning strike we sat out the first hurricane to hit the Rio Dulce River in 100 years---Hurricane Mitch. It was a real lucky year for us. No damage from the hurricane, and we had insurance coverage for the lightning.

Celestial is fun and very handy when the lights go out. And one additional thought, always have Paper Charts to back up the electronics.

Keep living your dreams.

[tartansailor]

"

Slide rules have gone the way of the dodo bird

Really?
Have you ever tried?
Did you ever loose a HP 48SX to salt spray?
May I respectfully suggest that you have your eyes examined.

Dick

[Steve Laume]

I have never learned how to use a sextant or at least not to determine my position with it's aid.

I did squeeze out a passing grade in high school geometry by doing a special report on celestial navigation. The facts that the teacher probably knew less than I learned about the subject and wanted me to pass probably helped but I do owe something to this form of navigation.

I once heard a line in response to weather or not a navigator kept a sextant on board in case his multitude of GPS devices failed. His reply was in the form of a question; "Do you keep a horse and buggy in the garage in case your car breaks down?".

Is a hand held GPS not tied into the boat's electrical system truly isolated and immune from lightning damage? Tupperware in a metal box?

I have to admit it would be very cool to learn this skill, Steve.

[fenixrises]

Hi all,

One of the reasons I did not carry my sextants is the cost of a new almanac every year. However a simple search on the web shows a multitude of free pdf files of the almanac and numerous freeware programs for doing sight reduction and plotting.

Got me to thinking about liberating my sextants from storage...

Here's a Google page filled with links.

http://www.google.com/search?q=freeware ... mages&tbs=

Take care,
Fred

[Neil Gordon]

"Do you keep a horse and buggy in the garage in case your car breaks down?".

If your car breaks down, you call a cab or you walk. This is more akin to leaving the oars in your dinghy despite the outboard.

[Jeff and Sarah]

I think GPS units are cheap enough now, and good (not plastic) Sextants are expensive enough now, that the biggest reason to carry one these days is simply an interest in the subject. Debating the value of a sextant in the face of a global GPS system shutdown is a bit of a stretch because unless you stay fairly proficient and practiced with celestial nav, you likely won't be able to find your position anyway. It is certainly a discipline that requires practice.

I do love celestial nav, and back in my days at Texas Maritime Academy I could find my position with equal accuracy to a GPS. That was some time ago though (and from a far more stable position on a ship than than one on the coachroof of my CD) and these days I'd be in a tight spot if I had to find myself with celestial bodies alone. I'd probably just end up sailing east or west to the nearest continent- and if I wasn't sure which one was closer, I'd figure I was in the middle and pick the one with nicer weather for that time of year. Not to mention, the calculations are a fairly time consuming task.

If someone is interested in the subject I'd encourage that person to learn to use a sextant. If someone were considering it for a practical application, I'd encourage that person to at least consider buying a few more GPS units with associated backup power sources. To each his own, and nobody can tell someone how to run their own vessel, but GPS sure is convenient and I'm confident both Magellan and Columbus would have used it if it were an option!

[Jim Davis]

Having used the sextant at sea for serious navigation on small craft, read pre-LORAN, I found it not that difficult, nor the arithmetic that hard. Granted that with GPS you have real time information spoon fed to you, it is nice to have the ability to determine your position should the electronics fail. Not only can a lightning strike leave you lost, but I have had electronics fail due to getting wet or low battery.

The sextant does require practice to obtain any reasonable accuracy, but this is mechanical skill and not difficult to achieve. Using the Nautical Almanac and Pub. 249 makes the arithmetic simple. It is all adding and subtracting along with filling in the blanks on a form. While I do not use a plastic sextant, they are capable of producing the accuracy needed for small boat navigation and would keep the cost down.

While I rarely carry a sextant for trips where I am in sight of land, I do take it for off shore trips. On off shore trips I do take some sights for practice and enjoyment. There is something satisfying proving that you can still navigate "properly". It also gives a nice break from routine chores and reading. While I do not use a calculator, or computer for navigation, I have changed over to using cheap quartz watches (Timex) as my chronometers. Side note: Don't use two time pieces for navigation, three work best so if one craps, you can spot it right away. Time ticks are easily picked up with any short wave receiver for checking your watches.

When considered against the other costs of operating a boat at sea the price of the needed publications is insignificant. While I have used several of the "short tables" I find that 249 is the most practical for use at sea. The easy look up and simple arithmetic reduces the errors and nearest mile is fine for fixes of three to five mile accuracy.

Bottom line Being able to navigate without electronics is a worthwhile pastime that sets you apart from the herd and just may get you home without too much hassle.

[Bruce Cumming]

I have been reading the discussion must confess due to my location, I may not get a chance to do celestial navigation.
However I would like to learn and have found it difficult to locate any boating classes other than the basic one offered by the USPS and the CG Reserve.
I have searched a 100 mile radius without much luck.
How are the online classes offered by companies like Starpath, or even a USPS one through a college in Florida?
I live in upstate Ny have did, until recently sailed the Finger Lakes.
We are just stating the search for another sailboat.
Thanks, Bruce

[Jeff and Sarah]

Be sure you are searching USCG Auxiliary, not USCG Reserves. Confusing the two will hinder your search.

[Jim Davis]

Bruce

I really can't comment on the online courses and the US Power Squadron celestial courses are member only courses. You might want to check community colleges and adult education classes within a reasonable driving range.

But when you consider that many celestial navigators are self taught using any one of a number of books, the online might well work. Starpath has been around for quite a while.

A few links:
http://www.celestialnavigation.net/

http://www.celnav.de/

http://www.celestaire.com/pdf/BooksSoftware.pdf

and my favorite for teaching
http://www.amazon.com/Sky-Sextant-Pract ... 0442211368