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post #21 of 29 Old 01-11-2018
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I have taken the USPS JN and N courses. Good courses but very time consuming as they cover more than just the mechanics for taking and reducing sights..
Yes..and upon completion of both courses (JN an N )and submitting your practical sight folders to the Navigation committee for review..it's damn close to completing a Masters degree..

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post #22 of 29 Old 01-11-2018
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Re: Online Celestial Navigation Course (free)

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Personally, I'd put that worry a few steps below getting hit by lightning or a meteorite at sea......
My concern is cyber security. I think it's just a matter of time. This isn't a bunch of nerd in their parent's basement. It's organized state sponsored cyber terrorism. Think about the chaos that would occur if the gps network went down for just one hour. It's a rich target.


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post #23 of 29 Old 01-11-2018
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Re: Online Celestial Navigation Course (free)

Here's a dated post I made on noon shots many years ago. Fun. Not hard to do.

https://www.sailnet.com/forums/819052-post16.html


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post #24 of 29 Old 03-07-2018
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Re: Online Celestial Navigation Course (free)

About 10 years ago i was out on Galveston Bay, Texas. While sailing back to port My Magellan Nav 600o suddenly shifted my reported position 5 miles to the north. It was evening with good visibility. I was on approach to the Clear Lake channel when the shift happened. Having the channel markers in sight about a mile ahead I disregarded the GPS and continued on my way. The following day I called the coast guard in Galveston to see if they had reports regarding the GPS system. After a rather lengthy discussion the officer relented with the following. I can neither confirm nor deny the government altered the GPS system but chances are it wasn't you GPS. Good news, I didn't have to replace a defective unit. So the moral of the story is The GPS system is occasionally altered or is incorrect.
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post #25 of 29 Old 07-31-2018
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Re: Online Celestial Navigation Course (free)

I recently watch some vids on the youtube "Navigation Training" channel, the presenter Chris, provides very lucid description of celestial basics from just finding latitude with noon sight, through to running fixes with repeated sun sights, and of course star and moon shots too.

Well worth watching if you are just dipping your toe into celestial.
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post #26 of 29 Old 08-07-2018
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Re: Online Celestial Navigation Course (free)

[quote=Donna_F;2051338810]This was posted in my sailing club email list. I haven't looked too closely beyond "free" but it might be worth investigating if you're interested.

Thanks for posting, I like the positive vibe for anyone interested.

Why do those who are to lazy to bother or just not interested keep trying to discourage those who are? with their negative vibe. Its not like anyone is suggesting they have to bother if they don't want to
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post #27 of 29 Old 08-22-2018
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Re: Online Celestial Navigation Course (free)

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Originally Posted by travlin-easy View Post
The best accuracy I was every able to obtain was +/- 9 miles, which ain't worth a tinker's damned when you're trying to find an inlet along an obscure coast.
In the middle of an ocean, nine miles ain't bad. Before GPS, I was always amazed at how accurate a sextant and dead reckoning could be. The closer you get to land, the more serious you get about your celestial sights and the accuracy of your dead reckoning.

Back in the day, because of the expected low precision of celestial and dead reckoning, we were taught to intentionally overshoot a landfall one way or the other, never try to hit it exactly. When you made the coast, you had a pretty good idea of which way to turn to find your inlet.

That, and always make landfall in the early morning, so you can see any lights on shore to help locate where you are. By the time the sun comes up, you're ready to navigate into the harbor, inlet, etc.

With GPS, these lessons are pretty much outdated I suppose, although I believe making landfall several hours before sunrise for reasons stated may still be applicable.

Last edited by wingman10; 08-22-2018 at 06:25 AM.
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post #28 of 29 Old 09-07-2018
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Re: Online Celestial Navigation Course (free)

I recently completed the Vanderbilt course. It was very good. It explained how celestial navigation worked in theory, but did not explain how the values used in the calculations were determined, since everyone but a PhD in astrophysics is just going to look them up anyways. The course does not claim to teach you other uses for a sextant such as range finding, but this information is easy to understand and fairly intuitive and can be found in almost any basic book on navagation. It does only cover using the sun as your celestial body. It says it covers other celestial bodies in the supplemental material, but I could not find that. That being said using a sextant is an art that must be practiced and will always be limited by the physical environment. I think it is a great skill to have, even if you never need it. Like learning CPR, a defibrillator, epinephrine, and intubation work better, but...
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post #29 of 29 Old 09-07-2018
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Re: Online Celestial Navigation Course (free)

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Originally Posted by dog-star View Post
t explained how celestial navigation worked in theory, but did not explain how the values used in the calculations were determined, since everyone but a PhD in astrophysics is just going to look them up anyway.
Well, it is the theory and practice: how to fill the sight reduction form. How the values are determined? .... that's trigonometry, and I think nobody wants to go there.

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The course does not claim to teach you other uses for a sextant such as range finding, but this information is easy to understand and fairly intuitive and can be found in almost any basic book on navagation.
...Celestial Navigation Course, not principles of Navigation 101.

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It does only cover using the sun as your celestial body. It says it covers other celestial bodies in the supplemental material, but I could not find that.
I can see the SM at the end of the course in this link: https://my.vanderbilt.edu/astronav/review/. It shows examples with the Sun and two stars. At the sight reduction form it show the field with "Additional Corrections (Mars/Venus/Moon)", which are taking (if I am not wrong) from the almanac.
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