Celestial Navigation

Well, I suppose I will ask since it is on my mind. This 'is' an aviation/marine oriented site and I am seaplane rated. (although Im nowhere near current) Has anyone deciphered/demystified the hocus-pocus math involved in using a sextant. I have tried a couple of times to master it, but I keep loosing interest since I am probably the only person within 300 miles who actually owns one. <br> Short of actually going to the coast and taking a class from the Coast Guard; does anyone have any ideas on how to make this easier?

K,<br><br>I can barely navigate from my house to work. As far as celestial navigating goes though, I thought that the math was already done. Is it not "take a sight, check the table, presto--your location. I know, I know, you have to know the time, and I think you need two sights, but I'm pretty sure the math is already done. All you have to do is check a table/chart somewhere. The big-brains with the slipsticks in their heads at the Naval observatory have already done the math. Anyone confirm/deny this?<br><br>Take care,<br><br>Andy

I wish it was that easy. Taking a sight is the easy part. Taking a noon sight for longitude (with a chronograph) is pretty easy also. After that you enter fuzzy math. The nautical almanac assumes that London is the center of the universe and everything revolves around it. Well....why not? Gotta start somewhere. They did control the seas at the time these things were perfected.

If you own a PDA there are good programs to do the math.

I learned the sextant with the aid of Knight's Modern Seamanship, Dutton's Navigation and Bowditch's Practical Navigator. I heartilly recommend these texts for falling asleep when you 've consumed large amounts of caffiene. I still needed the kind administrations of a chief quartermaster to become proficient. Until you can find such a resource, I recommend practising 'the heroic pose' in a mirror. Don't forget Old Spice for mariners and BayRhum aftershave for aviators ;O)

" I heartilly recommend these texts for falling asleep when you 've consumed large amounts of caffiene."<br><br>No doubt. Second only to John and Martha King videos or morse code practice. I cant decide which I hate worse.

I learned how to do a celestial fix in a Naval ROTC course 14 years ago and have long since forgotten the details. If you have a local college with an NROTC program, they may still be offering a similar course which you could audit, although with the advent of GPS, celestial navigation has probably become all-but-obsolete even in the Navy.<br><br>I agree the math is a real headache, not to mention the bulkiness of the reference books that are needed (which must be kept up-to-date) and the necessity for sub-one-second time accuracy. I recall it taking two people to use the sextant and chronometer together and something like an hour or more to work out the math with a pencil and basic calculator for just one single fix (using three stars). I can't imagine trying to work through it in a storm-tossed small craft, for instance. The only practical way to tackle it is with a dedicated handheld celestial computer (or a Palm computer with the appropriate program installed, as mentioned in an earlier post). But if you are going to use such electronics, the question becomes why not just go with a GPS unit?<br><br>You must be interested for the sake of intellectual curiosity. If so, I admire that. Good luck. <br><br>On the other hand, you might be able to skip the heavy celestial calculus if it would satisfy you to just learn a couple of neat tricks that you can do with the sextant. For instance, you can directly measure your latitude with a simple shot at the North Star (Polaris) to an accuracy within about one half of a degree, which can be made more precise using a table for adjustments. And I believe you can fix your longitutde with your sextant by measuring the peak of the sun's arc at mid-day, recording the time, and doing a table look-up or some calculations that are less rigorous than a full-blown celestial fix. You can also get your latitude from the same sun shot. You might be able to search up the details of these procedures and the necessary tables on the internet or in a library.<br><br>BTW, I don't think the sextant is of much use inland because you need a clear view of the true horizon, which is best seen at sea or from an aircraft. However, in our class we used the sextant from the roof of a bell tower, so it is not impossible in all inland areas.

"The only practical way to tackle it is with a dedicated handheld celestial computer (or a Palm computer with the appropriate program installed, as mentioned in an earlier post). But if you are going to use such electronics, the question becomes why not just go with a GPS unit?"<br><br>Because the celestial navigation method will still work when GPS goes down.<br><br>(But not when it's cloudy. ;-) )

have a look at this site- I didn't go thru the process, cause I don't have any sextant,so it is rather irrelevant...but still..<br><br>http://www.celestialnavigation.net/practice.html<br><br>Have fun

excellent