Sextants

[gjordan]

The old navy guy using an RDF got a laugh out of me. I used an RDF all up and down the Calif/Mexico coast and even used it on Aero beacons in the Tuamotus. I loved it. I also used a Radio Shack time cube for WWV and was my weather reports for the Pacific. I did have a Zenith Trans oceanic that I could usually only get religious stations on. It was a simpler time and nobody was afraid to leave the dock if they didnt have $20K worth of electronics. I commend people for learning celestial, even though nobody really needs it until the day GPS crashes. I suspect that there will be 500 epirbs going off when GPS crashes. Maybe it will never happen, but it just might. _____Grant.

[evm1024]

Originally Posted by gjordan

The old navy guy using an RDF got a laugh out of me. I used an RDF all up and down the Calif/Mexico coast and even used it on Aero beacons in the Tuamotus. I loved it. I also used a Radio Shack time cube for WWV and was my weather reports for the Pacific. I did have a Zenith Trans oceanic that I could usually only get religious stations on. It was a simpler time and nobody was afraid to leave the dock if they didnt have $20K worth of electronics. I commend people for learning celestial, even though nobody really needs it until the day GPS crashes. I suspect that there will be 500 epirbs going off when GPS crashes. Maybe it will never happen, but it just might. _____Grant.

Much the same here. RDF up the Washington coast and HCJB from Quito on the shortwave. HCJB has (had?) the strongest signal in the world.

Memories....

[svHyLyte]

Originally Posted by GrowleyMonster

.... Timex stem wound wristwatch, (why Timex? I don't know, but he loved the brand)

Jeez--Kids today. Because a Timex "Takes a lick'n and keeps on tick'n!"

[gjordan]

I wish I still had my old windup stop watch. It was a real classic. I left Mexico having just learned to do a sun LOP and within a week or ten days could do sun, stars, planets and the moon. It was great fun but it was a relief when the first Island peak showed on the horizon. Until that point there is always a little doubt. ____Grant.

[TeddyDiver]

Originally Posted by gjordan

Just another comment about doing noon sites. If you are actually planning on using a sextant for anything more than an emergency, I would highly recommend NOT LEARNING HOW TO DO A NOON SITE. The reason I say this is that many of the cruisers that I met before the age of GPS learned to do a noon site and patted themselves on the back and that was as far as there skill went. It is not that much more knowledge to do all of the celestial bodies and if you have spent several days with cloud cover in the midday you will be glad that you can take shots anytime of the day. Also for day time sights it is good to cross the sun and the moon (when available). Just my opinion! ____Grant.

To be patting on the back seriously you actually don't need a sextant. Just time the sun rise and down times (if it's cloudy use camera exposure meter to know when the sun rises) and do the math with nautical almanac. Only stay in port during equinox

[psk125]

Originally Posted by gjordan

I suspect that there will be 500 epirbs going off when GPS crashes. Maybe it will never happen, but it just might. _____Grant.

And then what? How will they find any of them if GPS has crashed?

[WingRyder]

WOW! The prices of these things is staggering! On amazon, the Davis Mk25 is $165 US, The Tamaya is $1900!!! I bought a 12' dobsonian telescope for half that, and a Celestron 8" with right ascension drive for $1200... apples/oranges, perhaps. But it is still a precision instrument. I can't see a valid reason for these instruments to cost that much

The price difference is clear. If you can get +/- 5 mile accuracy from a Davis @ $165, that's a no-brainer for me. I would only want a sextant, to play around with, and as a last resource to backup electronic navigation anyway.

[Benz]

What sets the Astra apart from the various plastic sextants is not simply the stability of the frame: the optics are far, far better, allowing you to shoot dimmer stars more easily. In fact, given the results I've had with my Astra IIIB, I'd say the only improvement it could have (there's never index error) would be even better optics.
I've had decent results with an Ebbco and Davis MK15, but they're not as consistent as the Astra, and as I said before, the mirrors, shades and eyepiece are far better.

[SV_Harbinger]

Well I did it I bought myself the Astra IIIb, the price wasn't cheap by any means, about as much as the outboard for the dink
Once I get to play with and get used to it I'll come back an post what I think of it compared to my current Spencer Browning antique.
And I thank every one who has contributed to this thread.
And regarding the ability to do a noon sight vs a LOP, when I was being taught, I was told that if you could make 3 circular LOPs then noon sights don't matter much except as a point of convenience. I was also taught that when we'll off shore even a single circular LOP is better than nothing even if only because it will tell you where you aren't...

[gjordan]

The optics are what make a sextant good or not. It sounds like Astra is very good. The most technically accurate instrument in the world is no good if you cant find the star because of less than good optics. Dont sell older sextants short on optics. I had a 70 year old scope on my dads hunting rifle that was as clear as could be and great light gathering characteristics. Some of the older sextants will have great optics. I often wonder about the WW2 navy sextants or the Russian ones that come on the market. Russian rifle scopes are good quality, maybe their sextants are also and a lot less pricey. ____Grant.

[SeanPatrick]

Originally Posted by SV_Harbinger

Well I did it I bought myself the Astra IIIb...

When I switched from the Davis to the Astra I was very happy I did. The Davis is nice to play around with and, as I have said, can be used to navigate. But the convenience of not having to constantly worry about index error is so nice. Also, being a heavier instrument, it tends to be more stable when taking sights. And look at it this way: the Astra is a well-built, quality instrument that can be handed down or even re-sold for a good price. As long as it is taken care of, it can last many lifetimes.


Speaking of taking care of it: if you need any tips on adjusting, using or maintaining your sextant, feel free to ask. That also goes for the practice of cel-nav in general. If you're not already familiar with it, I'd love to explain the "time sight" and how it complements the noon sight. These two methods were the daily routine for sailors from the time of the proliferation of chronometers (ca. 1850) right up until the invention of electronic methods of navigation. And there's no need for plotting - you get your latitude and longitude directly from a few simple calculations! (If you really want to get in-depth, I can also help with lunars and other methods.)



On a side note: I did visit the Stanley of London page and noticed that they now offer "calibrated" sextants - one of which looks very much like the Astra IIIb. I suspect that this sextant is indeed made by the same factory which makes the Astra: the Chang Zhou Celestaire Co. (Yes, the Astra is made in China.) Ken Gebhart, the CEO (and founder?) of Celestaire once stated that the Cassens and Plath "CP Sailing" sextant was also made by the same factory and simply branded for C&P.