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16-02-2010, 12:35
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#1
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Registered User
Join Date: Nov 2008
Location: Panhandle of Florida USA
Boat: Bristol 34
Posts: 328
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Time to Buy a Sextant ?
For the past year I have been enduring the taunts of my fellow marina bums regarding my purchase of a sextant, many books on it's use - not to mention the many hours of torturing my poor brain learning to use it.
"Why go to such trouble when you have three GPSs aboard"? Is an often asked question.
Well, my answer has usually been that they (the taunters) obviously have a great deal more confidence in the U.S. government than I do - and the government controls the GPS grid and can switch it off any moment.
Seems that I overlooked the other inequities in the system, as pointed out in the following article:
Solar flare puts GPS off the air -- Government Computer News
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16-02-2010, 12:43
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#2
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Registered User
Join Date: May 2008
Location: Sweden
Boat: Between boats
Posts: 474
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I have a sextant. I've spent the past 10 years working as a marine electronics engineer... Which is why I got the sextant...
/Hampus
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16-02-2010, 13:15
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#3
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Registered User
Join Date: Oct 2008
Location: San Diego
Boat: Farrier f27
Posts: 704
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For me the question is more why not have one. It is true that a lot of books and people teaching sight reduction make things complicated but it doesn't have to be. A simple form and fill in the blanks is all that's necessary, it's more matter of practice.
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16-02-2010, 13:21
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#4
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Registered User
Join Date: Oct 2006
Location: The boat lives at Fidalgo Island, PNW
Boat: 36' custom steel
Posts: 992
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Quote:
Originally Posted by Hampus
I have a sextant. I've spent the past 10 years working as a marine electronics engineer... Which is why I got the sextant...
/Hampus
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That's rich.
Got mine; thanks for the confirmation.
__________________
John, sailing a custom 36' double-headed steel sloop--a 2001 derivation of a 1976 Ted Brewer design.
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16-02-2010, 15:29
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#5
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Registered User
Join Date: Jun 2007
Location: Northern California
Boat: finally a catamaran dive boat...
Posts: 505
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I see how the gov't manages everything they touch and with that in mind... I have mine, my calc to assist me and taught my kids as well. Anyone can read a digital display but when it reads all zeros' then what. LoL
__________________
the perfect dive boat is one you're on...
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16-02-2010, 16:28
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#6
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Registered User
Join Date: Jan 2010
Location: Wells, Vt
Boat: 42ft Colvin Gazelle - TLA HLA
Posts: 503
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It's just plain fun to add to the knowledge bank!
Astra IIIb Sextant
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16-02-2010, 16:36
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#7
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Registered User
Join Date: Dec 2009
Posts: 2,959
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I'll fall back to dead reckoning if GPS goes down. Worked for thousands of years. Sextants were a 'flash in the pan' in regards to sailing history. But it can be fun.
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16-02-2010, 16:39
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#8
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Registered User
Join Date: Nov 2008
Location: Hobart Australia
Boat: Catalina Morgan 45
Posts: 350
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Not sure what's you're referring to here. I guess the word is a combination of "sex" and "tantric".
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16-02-2010, 17:05
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#9
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Registered User
Join Date: Jan 2010
Location: Wells, Vt
Boat: 42ft Colvin Gazelle - TLA HLA
Posts: 503
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Even with deduced reconing on has to have bearings of some kind to give their possition credibility. Time, speed, tide and current, windage all go into the guess. Soundings can help as can compas bearings on known waypoints. Every bit you can get! A sextant can help. As can a gps. Tantric sex however has always seemed to distract aquiring any fixed point in time and space for me though.....
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16-02-2010, 17:32
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#10
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Registered User
Join Date: Aug 2009
Location: between the devil and the deep blue sea
Boat: a sailing boat
Posts: 20,420
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Quote:
Originally Posted by daddle
I'll fall back to dead reckoning if GPS goes down. Worked for thousands of years. Sextants were a 'flash in the pan' in regards to sailing history. But it can be fun.
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Ye, sure - unless you happen to be mid-Pacific.
b.
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16-02-2010, 18:28
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#11
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Registered User
Join Date: Apr 2008
Location: U.S., Northeast
Boat: Currently boatless
Posts: 1,643
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Quote:
Originally Posted by rover88
[...]they (the taunters) obviously have a great deal more confidence in the U.S. government than I do - and the government controls the GPS grid and can switch it off any moment.
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True. The government also controls WWV time service which you'll need to compute longitude.
Quote:
Originally Posted by rover88
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Again, true. GPS service was interrupted for 15 to 30 minutes, depending on the type of receiver. Just about enough time to take out your sextant, take a sun or star sight (provided it isn't cloudy), get your nautical almanac and sight reduction tables (produced by the same government--or do you trust the Brits more?), calculate your position, and plot it on a chart based on some government's soundings.
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16-02-2010, 18:33
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#12
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Registered User
Join Date: Dec 2009
Posts: 2,959
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Quote:
Originally Posted by barnakiel
Ye, sure - unless you happen to be mid-Pacific.
b.
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No problem whatsoever. I'd know what latitude I as at when gps quit. Simply keep sailing towards paradise. Bound to find something. I'd ask the locals where they are when I get there. That's real sailing.
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16-02-2010, 18:57
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#13
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Registered User
Join Date: Nov 2008
Location: Panhandle of Florida USA
Boat: Bristol 34
Posts: 328
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Quote:
Originally Posted by Ziggy
True. The government also controls WWV time service which you'll need to compute longitude.
Ah, but they don't have a monopoly on timekeeping. A $35 Casio watch will keep perfect time for a few years. My battered thirty year old Rolex only looses a predictable 15 seconds a month.
Again, true. GPS service was interrupted for 15 to 30 minutes, depending on the type of receiver. Just about enough time to take out your sextant, take a sun or star sight (provided it isn't cloudy), get your nautical almanac and sight reduction tables (produced by the same government--or do you trust the Brits more?), calculate your position, and plot it on a chart based on some government's soundings.
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Do a little more research. The predicted interference of solar flares in coming years is far greater than a few minutes here and there. Okay, so even if it's occasional would you trust your life to a GPS knowing it may - or may not - be accurate?
Look, I love my chartplotter, handheld GPS and there is even one built into my laptop. I use them all the time and they are a true marvel of modern technology. I'm not knocking the technology by any means.
My charts, tables and almanac have been around for a long while and proven their worth to generations of sailors. I don't care if the boy scouts developed them as long as they serve my needs.
Trust what you like and put your confidence in a government or technology if you choose. I offer no apologies for my distrust in either.
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17-02-2010, 04:13
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#14
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Registered User
Join Date: Jan 2010
Location: actually in Brazil
Boat: sadler 32
Posts: 27
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it is common knowledge now, in the technical world of GPS, that from 2010 the aging GPS-network satelites are in a bit of a predicament. The US confirmed that from this year on there are no more spare satelites to be shifted in place if one of the satelites fails to work.
So we could be facing less precision from this year on.
As "the taunting" ones I thought I'd never have the need for a sextant ... thinking different now ...
Anybody an idea of "good" (read "easy to understand") literature about learning the sextant ?
thanks
Bas
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17-02-2010, 05:23
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#15
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Registered User
Join Date: Aug 2009
Location: South coast of England, moving around a bit.
Boat: Long range motor cruiser
Posts: 750
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The European satellites are slowly coming on line, as are the Russian equivalent so the reduction in the USA sponsored system may or not be a problem. Having a sextant and knowing how to use it seems prudent for every off shore voyager but I may be a little old fashioned on this. Certainly helped me for the first 35 years of my cruising experience. I've still got my RN issue sextant sitting in it's box carefully packed away in my cabin, with up to date reduction tables. For me it's one of those 'Don't leave home without it' items.
P.
__________________
The message is the journey, we are sure the answer lies in the destination. But in reality, there is no station, no place to arrive at once and for all. The joy of life is the trip, and the station is a dream that constantly out distances us”. Robert Hastings, The Station
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