Sextants - as useless as sudocu

[Conachair]

they seem an utter waste of good engineering and scarce personal grey matter.

Oh,but they are so beautiful

A bit pointless maybe but there are few excuses to go on ebay and buy such a precision toy that isn't electronic.

 

[Neil]

I bought one and learned how to use it without ever thinking that I would actually have to use it. I did astro just for the pleasure of it, and to learn a skill. I did want to learn how to reduce a sight without the tables (and without a calculator, though I still have my old slide rule from when I were a lad.) but I haven't, as yet.

What surprised me was that I wasn't the only oddball on the block; apart from the ebay sales, the chandlery that sold me my Astra IIIb told me they sold at least a dozen or so per year..........

 

[Simondjuk]

It's about being self-sufficient rather than relying on your essential data being spoon fed to you by some faceless agency, via a satellite somewhere in space.

If you don't instinctively understand the sense of satisfaction such autonomy brings, it probably cannot be explained to you.

 

[ChrisE]

It's about being self-sufficient rather than relying on your essential data being spoon fed to you by some faceless agency, via a satellite somewhere in space.

If you don't instinctively understand the sense of satisfaction such autonomy brings, it probably cannot be explained to you.

[/pedant mode on]

and the digital watch you use to know the time to make an accurate reading of the sun is not a product of the same technology as the satellites?

[/pedant mode off]

 

[Conachair]

[/pedant mode on]

and the digital watch you use to know the time to make an accurate reading of the sun is not a product of the same technology as the satellites?

[/pedant mode off]

I find the getting the time from the gps is that little bit more accurate

 

[Simondjuk]

You entirely missed my point. Last I checked, both my watch and the ship's clock were unlikely to be switched off, adjusted or in any other way messed up by any agency other than my own. Hence, the comment on self-sufficiency.

Neither timepiece is digital either.

 

[Conachair]

Main problem offshore I have is that the ais is always on and needs gps to work, so best that can be done is putting the cover on the gps. But even that is quite liberating, not being so hung up on knowing exactly where you are all the time but happy being a little vague knowing where you're not.

 

[timbartlett]

Why do you bother with sails: the wind is often in the wrong direction or too little or too much. And very few sailing boats can go anything like as fast as a motor boat. And most of them take their sails down and rely on a motor to park.

Similar sort of argument, IMHO.

 

[Sybarite]

I secretly admire those who still know how to use a sextant

but in my experience in UK waters

given the smallness of my boat

the cloudiness of my skies

they seem an utter waste of good engineering and scarce personal grey matter.

They are, in my opinion, about as useful as sudocu.

An utterly pointless intellectual excercise.

By the way my wife warned me that I would alienate one group of sailors after another until there were only three left who still agreed with.

Dylan

A log, a compass, DR and charts : what more do you need? It got me back from Ireland to Brittany. The Decca packed up on the outward passage. It was also all that I had on my trips over to Corsica.

 

[electrosys]

If you Google "eLoran", you'll find that an improved form of Loran is being suggested - which would be ideal for mariners, and without the huge expense of satellite technology and the paranoia of space junk running into 'em, or of them being switched-off.
eLoran wouldn't be quite so good though for aircraft ALS or for finding your way through the streets of London.

 

[Barnacle Bill]

Undoubtedly somewhat useless for coastal sailing, but on the ocean a sextant is slightly less useless than a GPS that isn't working.

 

[dylanwinter]

my GPS has never not worked

Undoubtedly somewhat useless for coastal sailing, but on the ocean a sextant is slightly less useless than a GPS that isn't working.

I have a spare one just in case it decides to not work

when tghere is no sun then the GPS is still working

I guess if both GPS devices quit I would not know where I was until it came back on

but then if the sun goes in I would not know where I was until the sun came out again

and if you dropped it on the way out of the camopnaionway hatch and damaged it in some way

how many people carry a spare sextant?


all I can say is

so far so good with the GPS devices from ebay

as for soduKo



it does seem to me one of the most brainless activities yet invented by man

on a level with rubics cube

mental labour with no real end result

Dylan

 

[Barnacle Bill]

I have a spare one just in case it decides to not work

when tghere is no sun then the GPS is still working

I guess if both GPS devices quit I would not know where I was until it came back on

but then if the sun goes in I would not know where I was until the sun came out again

and if you dropped it on the way out of the camopnaionway hatch and damaged it in some way

how many people carry a spare sextant?


all I can say is

so far so good with the GPS devices from ebay

as for soduKo



it does seem to me one of the most brainless activities yet invented by man

on a level with rubics cube

mental labour with no real end result

Dylan

All true, but I have such a lot of respect for people who crossed oceans before GPS was available (pre 1989?). I'm not sure I would have had the b*lls to do it.

 

[AntarcticPilot]

I find the getting the time from the gps is that little bit more accurate

No, it isn't. A good digital watch will provide time more precisely than a navigational GPS. You can get GPS kit optimized for time, but the kit is expensive and specialized - it is used (for example) as a time source on computer networks for precise synchronization. But the GPS you and I have on our boats can be wrong by several seconds; the electronics don't make extraction and display of the precise time a priority task. A good quality digital watch will keep time more accurately than that, and if the rate is noted and applied will be good to better than a second. And one that automatically synchronizes to radio signals will be accurate to a few milliseconds.

I think, though, that the point is that a watch (without radio synchronization) is independent of external requirements; it is totally self-contained. A GPS is not.

PS Good quality does not equate to expensive in this case - most of the cost of expensive watches is in the name on the case and the degree of "bling"!

 

[TimBennet]

If you are minded to become a regular and well practiced user of a sextant and astro then, apart from any personal satisfaction you may gain, it could be another string to your bow should the totally inconceivable happen to GPS.

However, no one should be fooled into thinking, that by buying a sextant and a few books and squirrelling them away aboard a boat, it somehow constitutes a workable, fail safe back-up system. You might as well spend the same money on voodoo dolls and a hot line to some god. The chances of teaching yourself and becoming competent, (or remembering some shore based course material from four years previous), when you're 'up against it' are slim indeed. Dead reckoning (or a generating an EP) are going to stand you in much better stead for a week at least.

However, if you are well practiced, some people find it a comfort that they can fall back on a system that is pretty inaccurate, weather dependent, prone to silly mistakes and errors, is reliant on a delicate mechanical instrument that is susceptible to knocks and salt water, and needs a time piece with a known error. Oh, and a dry set of up-to-date tables and almanac. Remember Mike Richey's decision to abandon Jester when the bulk carrier Nilam arrived, was that his paperwork and tables were sodden, and even if he could repair the damage to the cabinhouse, he was unable to continue safely, as he had lost his means to navigate. Who know's what the outcome might have been if he had a cheap GPS and batteries in a tupperware box stashed away somewhere.

Real safety at sea is largely dependent on making realistic evaluations of the risks and putting together practical and workable strategies to counter them. Do I still take my sextant with me? No, after 40 years I no longer think it warrants the space aboard.

 

[Conachair]

But the GPS you and I have on our boats can be wrong by several seconds;

There was actually a tiny bit of irony in the gps for time post

But thanks for the info, didn't know that.

Explains the errors in my sights

 

[Conachair]

You might as well spend the same money on voodoo dolls

Now these voodoo dolls, can you get them on ebay?

 

[Salty John]

I secretly admire those who still know how to use a sextant

but in my experience in UK waters

given the smallness of my boat

the cloudiness of my skies

they seem an utter waste of good engineering and scarce personal grey matter.

They are, in my opinion, about as useful as sudocu.

An utterly pointless intellectual excercise.

By the way my wife warned me that I would alienate one group of sailors after another until there were only three left who still agreed with.

Dylan

I've never tried to navigate by soduko so I couldn't comment on its usefullness. However, my mother-in-law seems to understand the technique - she told me she gets the Daily Maily so she can get her soduko fix. I wonder how accurate it is?

 

[Mariner69]

Undoubtedly somewhat useless for coastal sailing.......

Wrong on several levels.

We used to use several sextants, and the bodies to wield them, for precision navigation (better than the Transit system) in minesweeping and pilotage into ports. Required some pre-planning but very effective. Good enough to lead the team out on a Thursday.

 

[CreakyDecks]

Bligh and Shackleton managed to use theirs to good effect in small boats!