Celestial Navigation

cb32863 · Feb 18, 2016

ASA 107. I have a plastic sextant from Davis Instruments. Loads of books out there and online resources.
https://my.vanderbilt.edu/astronav/
http://thenauticalalmanac.com/Forum/
http://asa.com/certifications/asa-107-celestial-navigation/

Cue the arguments in regards to it is outdated, no one should do this anymore, its a pain in the. a$$, you can't do it on a passage as it is impractical.... These folks don't realize that some folks just want to learn it for fun. Yeah, the enjoyment of a "thing". EDIT: Oh yeah, then there are those that say you must learn it cause some evil doer HAX0R is going to bring down the GPS system with a few key strokes...

Rich Stidger · Feb 18, 2016

United States Power Squadron Junior Navigation and Navigation courses. Outstanding college level courses.

All U Get · Feb 18, 2016

ASA course using the Starpath books, I have them with me so I should give it a try.

All U Get

Gunni · Feb 18, 2016

cb32863 said:
Oh yeah, then there are those that say you must learn it cause some evil doer HAX0R is going to bring down the GPS system with a few key strokes...

No, the name is Ivan. Your Uncle Sam plays the game too.

Had an octogenarian submariner in my Safety at Sea class a few years ago who told us that although the Navy trained him in celestial nav and he used it to fix his boat across the Pacific during WWII, he no longer used it. Someone asked what he did instead, "I carry 5 GPS devices". Good enough for the CAPT, good enough for me! The Davis plastic sexton remains in the box. I do know how to plot and dead reckon on a paper chart, which in my mind is the minimum skill any competent boater should have.

heritage · Feb 18, 2016

I learned celestial during USAF Nav. school. Even then during the Vietnam era, most long range aircraft were being equipped with inertial nav systems, so celestial was becoming obsolete. I was assigned to a C-130 squadron that figured it was cheaper to feed a navigator than to invest in expensive inertial devices. We would take a celestial shot every hour on long transocean passages. It would take about 15 minutes to precompute where the stars should be, 2 minutes to take the shot, and about 5 minutes to plot it on the chart. Hopefully the resolved position would be within a few miles of your DR position.

I saw today on the news that hard copy photos are coming back. Some of the new generation have never held a photo in their hands and are enthralled with the idea. Celestial navigation may still have a future,, as a fun novelty.

Dave Groshong · Feb 18, 2016

USN, someone once said it takes 10,000 shots to be a pro, about right, my 6 years in the Navy I was able to achieve 3 mile accuracy consistently. Anyone thinking of crossing oceans can become proficient in sunlines in a short time, accurate enough to get to port.

Benny17441 · Feb 18, 2016

They should offer a course in Morse Code too?

Indysailor · Feb 19, 2016

My nephew told me he wanted a GPS for Christmas so I bought him a compass and the USGS quadrangle for his location. He was pissed, but my brother knew what I was saying, you have to understand the principles first. As to GPS v. celestial, or rather whether celestial is important to waterborne navigators, if it is an academic pursuit that helps a sailor understand the mechanics of navigation, it's probably worth while. And lets not forget, these guys are training to navigate during war time. I suspect if we are in a situation that has brought down our armed forces GPS capabilities, I'll be glad these guys know how to look up or bring the sextant down to the horizon and figure out where they are.

PotomacDaysailer · Feb 19, 2016

Took a Celestial Nav. class in college in 1979. I wasn't in the Navy ROTC program but the class was open and I was interested. It covered actual celestial navigation plus piloting and dead reckoning. I would need a whole lot of practice and restudy to identify stars and shoot altitudes, apply all the corrections and plot a position nowadays. No need for it on the lake where I'm never out of sight of the shore but it would be fun to relearn, preferably on a blue-water cruise.

Jackdaw · Feb 19, 2016

Anyone that missed the allure and frustration of CN should read Bill Buckley's book, 'Atlantic High'. You might not agree with his politics, but the man loved to sail, was a great storyteller, and possessed a massive intellect. My kinda guy. Just thinking about the chapter where the crew expects him to 'conjure up Bermuda' makes me smile.

Brian D · Feb 19, 2016

I too have a Davis sextant and have tried many times to use it. I should break it out and continue practicing. Very good topic.

wristwister · Feb 19, 2016

When I was a young teen back in the 70's, a salty old sailor at the marina taught me the basics of sextant navigation. It was the first time I saw the value of math, and I was fascinated. A few years ago I got one of those plastic Davis sextants at a swap meet and re-learned how to do a noon sighting. I'm proud to say I can reliably fix my position within a few hundred miles accuracy. I'm sure I could do much better, but ... umm ... the sextant must be out of calibration. Yeah, that's it, the damn sextant must be off!

smokey73 · Feb 19, 2016

Learned it at the Naval Academy in 1970. Was never very good and could get within about 25-50 miles from my actual known location. Did running lines on the sun on a Bermuda - Rhode Island passage in about 1979 (two people on a 38 foot Chrysler sailboat with an atomic 4). That along with a radio direction finder got us to the end of Long Island or so. But to be honest, we hailed commercial traffic when we saw them and got a fix from that. I have heard now days that many commercial vessels will not give a position over the radio (something to do with liability I am sure.)

Brian D · Feb 19, 2016

Everything is liability these days. Good grief, Charlie Brown.

WayneH · Feb 19, 2016

I have a book on CN. But something is wrong with it. Everytime I open it up, my eyes glaze over and I have to pick up a rum and coke to make it stop.

capta · Feb 19, 2016

I am a self taught celestial navigator. I used it for about 25 years to find my way across a bunch of oceans and seas and a circumnavigation. After several years of checking the first satnavs, I began to rely on them and with the introduction of GPS I have retired my sextants, taffrail log and chronometer, air nav tables, plotting tools, maneuvering boards and stop watches, hopefully for good. It was certainly a lot of gear to carry internationally as a delivery skipper.
Anybody who thinks that celestial navigation is a good alternative to or back up for GPS is fooling themselves, because the weather rarely cooperates with one's need to get one good sight, and one good sight is only a third of the minimum necessary for a reliable fix. Anybody can get a reasonably good sight in good weather, but when the sh*t hits the fan and you really need an accurate fix, you most likely won't get what you need unless your life has depended on celestial navigation for some YEARS. Don't forget you need an accurate deviation table, if you want to navigate celestially, so you are going to need to have your compass swung professionally every year.
I'm not saying don't learn, but consider it a fun pastime, not as an emergency navigation system. Buy a cheap handheld GPS for that purpose.

JamesG161 · Feb 20, 2016

cb32863 said:
Oh yeah, then there are those that say you must learn it cause some evil doer HAX0R is going to bring down the GPS system with a few key strokes...

You forgot the Zombies!!

They will shutdown the government and stop GPS.
Wait!
The take over has already started!

You forgot you need a good analog chronometer too.

Jim...

Jackdaw · Feb 20, 2016

capta said:
I am a self taught celestial navigator. I used it for about 25 years to find my way across a bunch of oceans and seas and a circumnavigation. After several years of checking the first satnavs, I began to rely on them and with the introduction of GPS I have retired my sextants, taffrail log and chronometer, air nav tables, plotting tools, maneuvering boards and stop watches, hopefully for good. It was certainly a lot of gear to carry internationally as a delivery skipper.
Anybody who thinks that celestial navigation is a good alternative to or back up for GPS is fooling themselves, because the weather rarely cooperates with one's need to get one good sight, and one good sight is only a third of the minimum necessary for a reliable fix. Anybody can get a reasonably good sight in good weather, but when the sh*t hits the fan and you really need an accurate fix, you most likely won't get what you need unless your life has depended on celestial navigation for some YEARS. Don't forget you need an accurate deviation table, if you want to navigate celestially, so you are going to need to have your compass swung professionally every year.
I'm not saying don't learn, but consider it a fun pastime, not as an emergency navigation system. Buy a cheap handheld GPS for that purpose.

Excellent reality check.

People often don't realize that you often might not get a sight for days, and only have vaguest idea of where you were, based on your last fix and some suspect DR.

Celestial Navigation

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