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Old 12-07-2011, 21:52   #1
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Tecnology vs Sextant

I guest a sextant is much like a spare wheel on a car ...which is not flat

You don't actually need it untill your GPS fails in the middle of nowhere so i am of opinion that it's certainly is a must for any boater!
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Old 12-07-2011, 22:10   #2
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It's more like a pencil and paper vs. A computer. It's not really a great 'spare tire' since it's actually cheaper and equally as reliable (arguably) to just have a spare gps.

It's old school, which is always considered better to some people. I got a sextent and fully intend to learn how to use it. But not under the pretence that I actually need it. I just like the idea of doing things 'by hand' instead of always taking the easy road.
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Old 12-07-2011, 22:12   #3
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Re: Tecnology versus sextant

Let me see - you buy some handheld GPS's on eBay for US$80 each or so and then you need to buy some AA batteries. Then you turn it on and in a few minutes, usually less than 5 minutes, you get a Latitude and Longitude accurate to several meters of where you are located.

- - Where would you buy a quality, metal, reasonably accurate Marine Sextant these days?
How much does such a Sextant cost?
What do you need to buy with it to enable you to get your Latitude and Longitude?
How long does it take to get that Latitude and Longitude?
And what is the accuracy of the Sextant Latitude and Longitude?
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Old 12-07-2011, 22:12   #4
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Re: Tecnology versus sextant

Well, Popeye, GPS is here to stay! Most people including myself have a backup GPS. Sextant navigation is very satisfying when you are rolling down the trades on a nice warm sunny day, however when the preverbial hits the fan then the acuracy falls flat and mistakes made especially if you are trying to read off tables and almanacs.
If you want to use a sextant or want it onboard for a backup I would suggest downloading an Astro nav program from Pangolin @ $40 US to your laptop, easy to use, acurate and very affordable!
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Old 12-07-2011, 22:21   #5
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Re: Tecnology versus sextant

Yea, i hear ya.. i gues the salt weans the brain cells somewhat! Thanks for that info not that i considder a laptop as to be reliable but then its only backup!
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Old 12-07-2011, 22:22   #6
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Re: Tecnology versus sextant

Suppose GPS completely fails. Maybe the US gov cannot afford the power bill ??? And you have no sextant. What is the worst that could happen? You're likely sitting at anchor or in a marina because that is where cruisers spend 90% of their time...or more. If you are actually out at sea on the typical problem? Is Florida or North America really that hard ti find? Seriously, carry a few weeks of extra water and rice...

Disclaimer: I carry a sextant and some very basic almanac data...
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Old 12-07-2011, 22:25   #7
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Re: Tecnology versus sextant

Well it's also like this. You buy a sextant as a backup and learn to use it. Then you use your gps and then after a period of time the gps breaks. Now you try and use your sextant but you forgot or you get an inaccurate fix because you don't use it everyday.

Another thing is the sextant is not very accurate no matter what you've read. Too many variables and you do need a clear horizon.

But remember a gps can go out, and for various reasons might go down

You should also learn emergency navigation skills. No sextant or gps
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Old 12-07-2011, 22:36   #8
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Re: Tecnology versus sextant

[QUOTE=SaltyMonkey;727781]Well it's also like this. You buy a sextant as a backup and learn to use it. Then you use your gps and then after a period of time the gps breaks. Now you try and use your sextant but you forgot or you get an inaccurate fix because you don't use it everyday.

Another thing is the sextant is not very accurate no matter what you've read. Too many variables and you do need a clear horizon.

But remember a gps can go out, and for various reasons might go down

You should also learn emergency navigation skills. No sextant or gps

NOW YOUR'E TALKING!!!!!
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Old 12-07-2011, 22:54   #9
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Re: Tecnology versus sextant

My personal opinion is you shouldn't get a sextant and tables as a backup navigation tool. Using a sextant - whether hand calculating or using a calculator/program - is a set of skills which needs constant practice to be accurate enough for coastal work.

Most cases I know of where gps gear has failed and the boat managed without mishap to get to port, the crew used very simple navigation to get to landfall, and then relied on Piloting skills to get to in. I would focus a lot more on the piloting than the sextant. (Which I do; the sextants only rarely live on the boat, but I've a hundred or so charts aboard at all times. And 3 gps these days when I leave port.)
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Old 12-07-2011, 22:57   #10
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Re: Tecnology versus sextant

I never had luck with a sextant in northern lats. Too much fog and smoke. Piloting is a necessity
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Old 12-07-2011, 23:04   #11
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Re: Tecnology versus sextant

An ongoing argument like the CF anchor debates.

I agree mostly with Jamels sentiments. I'm old school and have used sextant without GPS but probably wont use a sextant again since GPS is pretty reliable -but not infallible.
Having said that for offshore use I would carry at least three independent GPS, being so cheap, with at least one in protected storage - perhaps in the grab bag .
I'd also suggest one knowing how to take at least a noon site and carry, if not a sextant, then at least instructions to make one and a crude 'almanac' table of sun zeniths printed/written down. One could if desperate construct a primitive shadow type astrolab from a few bits of timber. Together with a little maths, a shadow measurement of say 5mm at a metre length equates to ~ 15nm mile lat. diff -enough to get by with in that unlikely event of WWIII or all 3 GPS failing.

I think I'm right in saying OpenCPN now has a celestial nav plugin available but I suppose if the GPS is dead then its likely the netbook is too. Theres plenty of celestial stuff available online.
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Old 12-07-2011, 23:14   #12
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Re: Tecnology versus sextant

Quote:
Originally Posted by otya View Post
An ongoing argument like the CF anchor debates.
.
Yikes this seems popular -6 new posts in the time it took to type mine -i must be slooow -cant keep up with the technology
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Old 12-07-2011, 23:15   #13
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Re: Tecnology versus sextant

The only way to truly practice primitive navigation and sailing is to get one of those logs I occasionally see in the San Juan's, jump on it and make a rudder and mast from the foliage still left on the log. Whatever clothes you have then can be converted to sails. Depth sounder? You look down. Where are you? You look around. Sextant? Make one out of a few twigs and your shoelace. Now excuse me while I go turn up the air conditioner because I am too lazy to open a window...

However, you guys may be on to something- sailing primitively. I only thing I would add is that sailing without current technology is not cruising- but it is a game worthwhile it its own right. As a former survival instructor, I would say that sailing with only what you can make and repair would be a rather interesting game, although I think the mortality might be higher. Lots of old sailors died sailing to the new world....
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Old 12-07-2011, 23:16   #14
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Re: Tecnology versus sextant

Am looking foward to continuing to practice and learn how to use mine effectively. This has less to do with redundancy, safety, etc. than it does with how I want to sail and what skills I can enjoy developing. I have my eye on a really nice one when I graduiate from my 2nd hand plastic model. It's like boat choices we make, the places we might sail, the how we want to get there. Glad I've got my GPS though, makes it easier to learn the sextant. Will always have a couple of handhelds around. I do not use an anometer...enjoy learning how to identify conditions. Probably won't get a chartplotter but will have a radar for solo work. None of these choices make me a better or worse sailor just the kind of cruiser I like being.
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Old 12-07-2011, 23:20   #15
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Re: Tecnology versus sextant

Newt common man get real here. Were tlking emergency navigation not survival or primitive living skills. I love flontknapping but I know well enough there aren't enough calories around these days.
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