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Celestial Navigation? Forget it!

60K views 329 replies 101 participants last post by  Valiente 
#1 ·
Today, Sailnet posted an article by Liza Copeland about the hazards of cruising.

The first third of the article was about navigation, wherein she declared that it was dangerous to "rely solely on electronic navigation." This is about the thousandth time I''ve heard this over the past few years.

In 20 years sextants will be rarer on boats than lubber lines are today. The reason: learning celestial navigation is a waste of time and money.

I have three GPSs on my boat. I didn''t buy three GPSs on purpose, but they''ve accumulated over the years. They never seem to fail, and the space required for the spares and spare batteries is tiny.

The problems with CN are: a it requires considerable skill and continuous practice to use it. It requires an extraordinarily expensive piece of optics to get even the fuzziest of fixes, it depends on a complex set of calculations, and -- here''s the topper -- a sextant is just as vulnerable -- in its own way as a piece of electronics. I''ve dropped my GPSs dozens of times (I guess eventually I''ll kill one); I wonder how many drops a sextant could take and still get a fix withing 1000 miles of position? If you drop it overboard, I guess the number of drops is 1. How many people can keep a spare $1500 sextant on board?

So, sorry to everyone that spent time mastering CN, and have dropped a lot of money on sextants. Your skills are no longer required. They might be needed some day, in some rare situation, and then you''ll be vindicated. But probably not. You''ll carry the damn thing around with you from now on, and keep looking at your GPS when you want to know where you are.

OK, all you grizzled sextant-totin'' old salts out there, let me have it. I can take it.
 
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#280 ·
Denby-

Did you hear something???
 
#282 ·
Hi Cam!!!!

Gotta use the big fonts, cause you know he's getting to the point where he can't see or hear very well anymore... :D :laugher ;)


bad, bad, bad doggie... good thing Cam don't got the big red button still.
 
#283 ·
I do not so much worry about lightning or solar flares, but I do worry about electric failure which in fact has happened to me several times during the last 40 years of sailing. That is why I learned CN and always have paper charts for the area I am sailing.

The Norwegian Maritime Directorate issues two kinds of certificate for leisure skippers, one limited to coastal areas, one with no limit concerning waters. (Deck officer Class 5, D5L and Class 5A D5LA, respectively). The difference between the two kinds is having passed an examination in CN. Authorizes up to 50 ton, all seas.

Of course CN is superfluous when navigating in coastal waters. Because in coastal water one is navigating by landmarks, buoys, lighthouses etc. As is GPS. That being said I am very glad I have GPS, it saves time and it is practical to have a little spot on my laptop screen. Also the GPS is a prerequisite for making the AIS work. The AIS is very convenient for calculating the course and speed of fast ferries and other big ships in areas where the traffic is heavy
 
#287 ·
This is the classic argument. Why do I need that old fashioned stuff when I have three perfectly good GPSs. There is a description in one of W F Buckleys books where he describes meeting a big, fancy, got it all sailboat somewhere, I think in the South Pacific. Freezer full of steaks, every electrical and electronic doo dad. They ran the batteries down and the generator failed. A hundred GPSs are good for nothing except ballast if they don't have power.

Even if you never go out of sight of land, my good old plastic sextant still serves me well as a piloting tool. Turn it on its side, use the bow as a reference and you have the perfect tool for getting LOPs. Many years ago (pre GPS) I was sailing in company with a friend on a cruise in Lake Michigan. We were trying to find the channel entrance to a small inland lake. We knew about where we were but just couldn't see it. I got a LOP on a smokestack and called my friend and asked him for a depth reading (my sounder was out of order, another example of relying on electronic devices. I now carry a lead line.). He asked what I needed that for. I told him to just tell me the depth. I crossed the depth line with the LOP, laid off a course to the channel entrance and told him what course to steer. We didn't see the markers until we were about a mile off but we hit it dead on. To this day he thinks I'm a cross between Christopher Columbus and Neal Armstrong but it was just a simple piloting exercise with a cheap plastic sextant.

I, too, won't be without my GPS voluntarily but, just as I wouldn't be without paper charts I won't be without my charts,sextant and sight reduction tables. They work without electricity.

Dick Pluta
AEGEA
Nassau, Bahamas
 
#288 ·
Good point, Dick. You can use the sideways sextant method, as you said, for quite accurate LOPs, or even as a quick and dirty method of determining distance off by measuring the angle of some chimney or radio tower ashore, assuming you aren't in heavy swells.

I am also of the opinion that the relatively simple math involved in CN (assuming you are working from almanacs) keeps the sailing mind sharp.
 
#289 ·
I don't know how to use a sextant. Although I own one. I had intentions of learning, and took a class. In 2 minutes I had a question, and raised my hand. The instructor said "Don't worry we will get to that!" A minute later another question, and same answer. Needless to say I NEVER LEARNED!

Soon I will will be leaving for Asia, and this time I will learn along the way. I don't think it's needed, but I don't see the harm in knowing. I also think it will bring you closer to the natural order of things......IMHO.......i2f
 
#290 ·
I believe that some people are very fascinated by the idea that mathematics can give us some knowledge about the world. I for one, am among them. It really is a pity that CN is not used as examples in school when the school teaches geometry and trigonometry. As examples from CN, would show how useful mathematics can be. That is, I find it very useful to be able to find my position by means of the relationship between angles and sides in (a celestial) triangle.

But if one is not comfortable with mathematics, the position can still be found be means of a navigational calculator or by using sight reduction tables.

Yet l I think that the motivation for learning CN stems from the insight of the beauty of the fact that the world obeys the rules of mathematics.
 
#291 ·
Want to see something truly amazing? Look back to the beginning and see when this thread started. I would be impressed by being able to find my way with CN BUT the age of this thread? Well, internet archeologist are going to be talking about this for years to come....
 
#293 ·
This is a debate about convenience. It is easy to simply press a button. GPS and associated electronic navigation charts are so much easier than actually looking out the window or using a "seaman's eye", a skill that is only developed over years.

One of the dangers in things electronic is the tendency of the user to accept data and not think about it. After all the arrow tells us exactly where we are! Right? Unforunately it doesn't always tell us where we are going, the secod part of navigation.

Check out ths link:

Maritime News - UK Grounding - Lack of ECDIS Training
 
#294 ·
Slocum—

One thing to realize is that there is no ECDIS system that is approved for use on a small boats AFAIK. The MK I Eyeball is still a far better tool in many ways.
 
#297 ·
This is my first year sailing and I already picked up a book for $4.00 (Sky and Sextant). Every time I go out in the Cheasapeake bay I try to learn something new. I thought when you are sailing you have pleanty of time to do CN. I have one question, is it much easier to get lessons on CN or just read up on it and practice.
 
#299 ·
lapworth,
Pick up a copy of Bowditch and start in. There is much there beyond celestial of value to you over a lifetime of reading. Then take a class; you're likely to have the same experience as denby.

If you're sailing offshore you certainly do have plenty of time to practice celestial and even squareknot the odd scrap of line into something useful. Others choose to utilize this time figuring out what went wrong with their TV remote control. To each his own, I suppose. (g)
 
#300 ·
I accidentally posted this on another CN thread. It's still true.

One final thought. In addition to all the practical reasons, it just feels good to lay out a little "cocked hat" on the chart and be able to say "Wow, I did that". It just a good feeling to able to do anything really well, especially when that thing is something that could save your boat, or life, or both.

Dick Pluta
AEGEA
Nassau, Bahamas
 
#305 · (Edited)
I try to link this every time i see it come up. American Practical Navigator is available in for free from the NGA:

Maritime Safety Information

Click on the complete version, or you can download each chapter. The complete version is 35 MB.

In adition to that, you can get all nautical publications for free by clicking on the "Publications" link on the left hand side of the screen and then choosing a pub from the dropdown list. You can get American Practical Navigator, Chart No. 1, Sight Reduction Tables, Radio Navigational Aids, Pilot Charts, US Notice to Mariners, etc etc. All are free for download.
 
#303 · (Edited)
You do realise that the only real way to check an error on a gyro compass is to take an azimuth. Also there are numerous computer programs which mr electronic i'm assuming you have on board that will work out sights automatically, so your'e argument is flawed.:D

The United States government has a program in its gps that allows them to change and disconfigure (they say it's disabled but come on) the system, this was used primarily in the cold war.;)

and also if you're going to lose sextants why not lose anything reasonbly old like learning to tie a monkeys fist (unless your vessel is considerably large, you have no need of a heaving line) e.t.c

We learn these things because one day we might need them.

Finally if you read the nautical almanac it talks you through how to reduce sights.
and this is coming from a person who's only 20 years old.


(ALSO i agree with denby the Bowditch is a brilliant book)
 
#307 ·
The United States government has a program in its gps that allows them to change and disconfigure (they say it's disabled but come on) the system...
Something like that. They have the ability to introduce random error into the non-military signal. It's currently turned off and, with todays dependence on GPS, it is considered unlikely it'll ever be turned on again.

Jim
 
#304 ·
So, I'll apologize for hijacking this thread, and please feel free to redirect me elsewhere on the forum if it's already been discussed.

I'm interested in buying a sextant to learn and practice CN. However I am fairly sure I'm not going to lose interest and therefore would not like to buy a "better" one someday. Finally, I am not wealthy.

So I'm thinking of either getting an inexpensive working reproduction, or finding one in a pawn shop or something. If I go with the latter option, any recommendations for how to examine a sextant to determine whether it's useful and in good condition?
 
#306 ·
Don't go with a reproduction one, since most aren't made with any sort of accuracy. You can get a decent sextant, either plastic or if your budget affords it, a metal one for less than you'd think. If you have questions about a sextant, the best book to get, is Bruce Bauer's The Sextant Handbook. It has a very good section on how to examine a sextant for specific problems, and whether the sextant is worth purchasing... :)
 
#308 ·
Celestial Nav is to GPS Nav what Morse Code is to Radio Communications. Both CN and Morse Code are now art forms practiced by people who truly enjoy using them. When MC was no longer required for an Amateur Radio license the doom and gloomers said the world was sure to end etc.etc. The same is being said of GPS now. Remember one must learn all sorts of interesting things (basic seamanship, basic navigation, using a compass, making sure you have enough fresh fuel for your aux motor, and on and on) before he or she can safely sail across a bay much less an ocean.
Yes I have a chart plotter, several GPS, a few paper charts, a computer filled with electronic charts. My most important tool is between my ears. I can see my compassd or listen for a fog horn if necessary. I know when to drop an anchor and wait out a bad weather situation. Taking unnecessary chances is not macho or wise.
If you believe that CN is a vital tool that you must have, take the time to learn it to proficiency.
Please enjoy your outing today as none of us knows how many more we have.
 
#314 · (Edited)
I won't diss the GPS crowd, but I have had GPSs go out on me more than once and It was and is a good thing that I could and can navigate by coast piloting and Celestial.
So for those of you who depend on the GPS 100% of the time, I highly recommend that you learn coast piloting and Celestial navigation and practice both contenuously. Then when the GPS does gives up the ghost, you are not left out on a limb or in the lurch.
 
#315 ·
Cn

I, too, am a fan of CN; as I was taught "the prudent navigator does not rely on any single means of navigation, but heeds all the navigational data available". Having said that I also believe CN is not the ultimate backup, always available. On a trip from Atlantic City, NJ to Cape May, NJ with a weather forecast of clear weather we were socked in with fog for nearly the entire trip. CN and coastal navigation were not possible with visibility of 20 feet; so without the GPS it would truly have been "brown pants" time. With GPS and radar it was still nerve-racking.
 
#319 ·
I, too, am a fan of CN; as I was taught "the prudent navigator does not rely on any single means of navigation, but heeds all the navigational data available". Having said that I also believe CN is not the ultimate backup, always available. On a trip from Atlantic City, NJ to Cape May, NJ with a weather forecast of clear weather we were socked in with fog for nearly the entire trip. CN and coastal navigation were not possible with visibility of 20 feet; so without the GPS it would truly have been "brown pants" time. With GPS and radar it was still nerve-racking.
You mean that you don't have a cloud splitter attachment for your sextant??:laugher
 
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