Online celestial navigation courses?

[Smokeys Kitchen]

I took a group course a while ago. Practice is what really makes the difference. We used the book "A Star To Steer Her By" by Edward J. Bergin.

We used 2 youTube videos in the class. 1st one is a Maryland School of Seamanship intro:

https://www.youtube.com/watch?v=kZCwgoUxXWs

The 2nd one is 12 part series by Practical Navigator. Produced and presented by Christopher D. Nolan.

https://www.youtube.com/watch?v=BMoW...8wTzXE4XaQU64E

The book and videos worked out great, but as I said practice was the best.

[jerrypeters]

Check out this series by Will Lesh:

https://www.youtube.com/watch?v=-ARXW8InStY

Two part program, total of 9 hours plus. I learned a lot.

[Paul Howard]

There is more to navigating across oceans by the sun, moon and stars than taking sights and reducing them to draw a line of position.
Many elements of coastal navigation are necessary to find an assumed position, advancing a line of position from an earlier sight to get a fix.
Also, when the sky clouds over for sometimes days at a time and no sights can be taken, one has to do dead-reckoning, estimating speed and direction of current, leeway, etc. Coastal Navigation is an essential part of celestial navigation when actually navigating across oceans using Celestial navigation.
And, remember when the U.S. military turned off the GPS system for non-military applications in about 1991? It could happen again.

[jshambl]

Also highly recommend the Starpath courses. The personalized feedback on quizzes is fabulous and you will walk away with a good solid understanding of the fundamentals, and the details for reducing various sights.

[jjjacq]

Originally Posted by tkeithlu

Do any celestial navigation users on the forum have advice regarding online celestial nav courses?

I recently lucked into an unused 1946 US Maritime Commission sextant. No index error, hasn't been dropped. Freighter level, not fancy Navy level, but sturdy and good for me. The math kicked my butt until I took Vanderbilt University's basic course, but I need more. What can you recommend for learning celestrial, given I'm not near a class therein?

You can use my web site: https://www.madinstro.net/sundry/navig.html

Item 5 gives you a bunch of calculators, even a general sun almanach (without the nutation correction but good enough to within 1 or 2 minutes).
Save the html files to your hard disk and they will work quite happily without Internet connection.

[SeanPatrick]

Originally Posted by Rainbow48

Take a look at the online website called “TeaCup Navigation”. Very simple explanations with downloadable navigation program.

I second the recommendation of this [FREE!] software. One unique feature is the ability to use a custom value of "delta-T" - or the difference between Terrestrial Time (TT, used in ephemeris calculations) and Universal Time (UT1, specifically). In other words: it allows for more accurate data over a longer period of time. This feature is rare among celnav programs.


I'm sure I also read Rodger's book and it was good, but I honestly don't remember.

[Auspicious]

Originally Posted by tkeithlu

Do any celestial navigation users on the forum have advice regarding online celestial nav courses?

I learned from StarPath twenty years ago. That and Bowditch worked for me. I also messed around with some spherical trigonometry to better understand the basis of the tables which was fun.

Originally Posted by carioca

Check your time via WWV. It's not unusual for the GPS time to be several seconds or more off from what WWV is broadcasting.

You can also correct WWV based on signal time of flight.

Originally Posted by Paul Howard

If they were all on one side of your GPS position, you are probably making a small error in taking a sight - could be as minor as your not holding the sextant quite vertical or, as you say, not having the height of eye quit accurate.

Absent an error in height of eye for the lighthouse you're practicing from taking a sight and getting the time right for the sight are the big errors. There is a reason small boat celestial navigators have scars inside their left elbows.

[tkeithlu]

Quote: "There is a reason small boat celestial navigators have scars inside their left elbows."

OK. I'll bite. How do they do that? Juggling their left arm to see their watches? I wear my watch on my right wrist, so it's hang onto the sextant while flipping it.

Anybody got an app that reads out GMT seconds vocally?

[CHAZ]

Originally Posted by tkeithlu

Quote: "There is a reason small boat celestial navigators have scars inside their left elbows."

OK. I'll bite. How do they do that? Juggling their left arm to see their watches? I wear my watch on my right wrist, so it's hang onto the sextant while flipping it.

Anybody got an app that reads out GMT seconds vocally?

Hanging on a stanchion (arm around a stanchion)


Happy 2020 and happy navigating


Martin

[Auspicious]

Originally Posted by tkeithlu

Quote: "There is a reason small boat celestial navigators have scars inside their left elbows."

OK. I'll bite. How do they do that? Juggling their left arm to see their watches? I wear my watch on my right wrist, so it's hang onto the sextant while flipping it.

Hanging onto a shroud with the sextant, trying not to move, and watch. This is easier with two people (one for the sextant, one for the watch) but you still end up with deep bruises inside your elbow that leave permanent marks. Bigger boats and of course ships are easier.

One hack is to use a stop watch - start it at the sight and correct when you get a time below at the nav station. I just get set, check the time, and count. Generally 2nm or 3 nm triangles.

"If I get lost I just pull in somewheres [sic] and ask directions."

[tkeithlu]

The "Celestial Navigation" iPhone app by Harald Merkel does the entire sight reduction, you just feed in the time and sextant altitude having set the conditions such as height. It gives you intercept distance and azimuth. Then it plots the LOP on a chart, and lets you export it as a PDF. It almost takes the fun out of it. I'm glad I did not discover it until after I knew the basics. I think I'll continue doing the sums myself, and use it to check my work.

[Sailor_Al]

You should look up your local United State Power Squadron USPS. Reach out to me if you want a hand finding your local Squadron.

[SeanPatrick]

Anyone with any specific questions can also post them here on the forums. I'd be more than happy to help.

[Cpt Pat]

Originally Posted by Auspicious

You can also correct WWV based on signal time of flight.

Considering you would have to be around 186,000 miles (three-quarters of the distance to the moon) from either Colorado or Hawaii (the two WWV transmitter sites) to see a one second delay, I doubt you would ever need to "correct" WWV for "signal time of flight." And if your sights are so accurate on a pitching and rolling boat that a one second delay matters, I'd like you teach me how you do that! I'm happy when my final longitudinal position solution is within 8 miles of my actual position. That's equivalent to a two minute error.

Beware of using GPS time as a time reference. GPS time may or may not be corrected by your GPS receiver for the missing leap seconds that are applied to UTC time (the time broadcast by WWV) -- but that are not applied to GPS time. UTC and GPS time are slowly drifting apart (there is now a 19 second difference), and it would cause a mess if GPS time was every resynchronized to UTC. Instead, the software developers have to process the UTC-GPS offsets to correct the displays on the GPS receivers. All software developers are idiots.

https://www.nist.gov/pml/time-and-fr...-questions-faq
https://www.ipses.com/eng/In-depth-a...ime-definition

I have a speaker in my cockpit. I just blast the WWV audio from my HF receiver for a time reference. As a backup, I also have a Casio Wave Ceptor watch that sets itself to WWVB. When it runs without a WWVB reference, it's only off by about 2 minutes a year. And that watch is a whole lot less expensive than a Rolex.