Any Suggestions for a Perfect Sextant ?

[JazzyO]

Originally Posted by ahaluk76

for JazzyO and İF the USA nsa want to cut gps power its probably possible in A minute.Where you are? how long distances : and how dangereous night and shallow waters rocks and all dangers whit out GpS.....

What on earth has that to do with your remark about cancer?


Onno

[Andrew Troup]

Originally Posted by gjordan

Jammer!, I have had my GPS lie to me, in my airplane. It was a clear day so it didnt do any harm, other than shake my faith in them. I was going out to an airport near the California coast and my recently purchased hand held moving map GPS was doing just fine. When I got within 4 or 5 miles of the airport, I started paying much more attention to the airport, and potential traffic, than the GPS. On downwind, alongside the airport, I glanced down at the GPS, and it had me about 15 miles out over the ocean. I was surprised, but since the airport was in full sight (and had been for miles) I continued my landing. When I stopped, the GPS showed me exactly where I was on the taxi way. I have no idea what went wrong, but it didnt build my trust in electronics. This was not a $99 unit from Walmart, it was an $800 Bendix aviation unit, and it still lied to me. It was one of those GO FIGURE? moments. _____Grant.

Good luck getting any converts, Grant.

I don't know how it is for GPS, but the usual circular logic for deeply held beliefs is against you, and it probably goes like this:

Player 1) GPS units do not lie
Player 2) My one did, so your claim is invalid
Player 1) I discount spurious data like yours
Player 2) How do you know it to be spurious?
Player 1) (sigh) because GPS units do not lie

[Jammer Six]

I think we should just go ahead and bring this argument home: carry paper, compass and sextant, practice heaving-to and running a lead line.

[ahaluk76]

nothings !!! its an idiotic joke maybe take some attentions. dont worru you right!!!!

[Capt GenlmanJac]

You do not garden to make money; in fact you LOSE money gardening... And I will continue to pick up my sextant for the same reason (That I cannot explain to you) that I continue to plant my own corn and tomatoes...

[a64pilot]

Originally Posted by Andrew Troup

Good luck getting any converts, Grant.

I don't know how it is for GPS, but the usual circular logic for deeply held beliefs is against you, and it probably goes like this:

Player 1) GPS units do not lie
Player 2) My one did, so your claim is invalid
Player 1) I discount spurious data like yours
Player 2) How do you know it to be spurious?
Player 1) (sigh) because GPS units do not lie

I used to ferry aircraft from Fl. to Central and South america. These are turbine powered crop dusters and have no avionics, so I would carry two handheld Garmin's, usually a 296 and a 396 for Nav. Somewhere I thought Damn I'm holding a good course line as usually every couple of minutes I'd have to make a turn, usually a left turn, seems I have a right turn built in. Anyway after awhile I noticed the mileage hadn't changed so I did a left and a right turn, with no indications at all on the GPS. It was simply locked up, frozen. None of the buttons would work, you couldn't even turn it off. I took out my back up and thankfully it worked.
I had to take the battery out of the 396 to get it back, it has always worked since then, that was a one time occurrence, years ago.


I cave dive and prefer a Shearwater Predator dive computer, I've always liked their statement on page four of their manual. remember this warning for all electronics
I cant cut-n-paste as its a .PDF, but look on page four under warning

http://www.shearwaterresearch.com/wp...nual_2_3_3.pdf

[carstenb]

I carry a sextent and I practice using as much as I can. Normally I prefer them to be at least 7 feet long - the one pictured is a bit short for my taste

[Dockhead]

Originally Posted by capngeo

In ALL of them?

1. 2 pucks
2. 1 handheld
3. 1 old 126 at the nav station
4. 2 GPS chipped cell phones
5. The chartplotter
6. An iPad

That's 8! Eight individual units that would all have to fail at one time! A lot better chance of it being cloudy and knocking the sextant offline! CRAP! I forgot the 2 SPOT locators! That's 10 individual, isolated GPS receivers in ONE boat!

I agree. There are two potential issues: (a) failure of your GPS receiving equipment; (b) failure (or intentional shutdown) of the GPS system.

Issue (a) is easily eliminated by sufficient redundancy. My boat is like CapGeo's -- in fact I would be hard pressed to actually add up all the GPS receiving devices I have on board. At any given time there will be at least a dozen mobile phones (including obsolete ones kept for backup) and tablets which are capable of receiving GPS, plus retired handheld GPS's, several GPS receivers on my nav network, etc., etc., etc. I really don't think this is an issue in the day and age when every cheap mobile phone has a GPS receiver built in. The chance of a normal cruising boat being without a single functioning GPS receiver seems vanishingly small.


Issue (b) can actually be eliminated by the same means -- redundancy. GPS is not the only game in town -- the Russian GLONASS system has been fully operational for a few years by now, and the European Galileo system should be up pretty soon. I bought a Simrad GS25 receiver for my nav network which gets all three systems (GPS, GLONASS, Galileo) and costs a paltry $199. My main mobile telephone (for Pete's sake!) receives GLONASS besides GPS, and since the Russians banned the sale of mobile phones without GLONASS, I think nearly all mobile phones have GLONASS now (since Russia is one of the world's biggest mobile phone markets).


So I think the risk of not having a satellite position fix is much lower than the risk of, say, losing propulsion, losing hull integrity (God forbid), losing the rig, etc. Therefore, it is not on my list of things to worry about.


And anyway -- even on the odd chance that you lost all ability to determine your position at sea, in the middle of the ocean -- so what? Why is that a disaster? Columbus didn't have any (even remotely) accurate way to determine his position. You will know what general direction to head in order to reach the nearest land mass; everyone knows how to roughly find E, W, N, S from sun and stars. Just keep going till you hit land, then make your way along the coast until you find a port, then guide yourself in using the buoys. Or radio the Coast Guard when you get within radio range, and let them determine your position by RDF.



Nothing against sextants -- I'd love to have one and I'd love to learn how to use it. But I don't personally consider it to be really important in this day and age.

[boatman61]

Luddite 'DUHHH..!!' question... will the GPS phones still operate out at sea.. eg; 200miles offshore..??
I've only just discovered ones with internet...

[a64pilot]

Originally Posted by boatman61

Luddite 'DUHHH..!!' question... will the GPS phones still operate out at sea.. eg; 200miles offshore..??
I've only just discovered ones with internet...

For navigation, yes at least the ones I have used do. I think turning them on airplane mode will greatly extend the battery life too, if you don't it will always be trying to connect to a cell tower that isn't there and the battery will die pretty quickly.

On edit, possible airplane mode on some will kill the GPS? If so you'll have to disable cell service, Wifi and Bluetooth separately if that's the case

[Snowpetrel]

Love the Bris sextant idea as a simple backup, pure genuis. Anybody used one?

I have a beautiful frieberger that does double duty as decoration in the house, and an old Davis mk 15.

I my case lots of problems with backlash in the Davis micrometer, giving about 12 minutes of error if I dont carefully use it. For a plastic one I would go a vernier scale, in use they seemed more consistant than my davis but then my Davis might be a dud.



Sent from my C6903 using Cruisers Sailing Forum mobile app

[Scott Berg]

1) Astra (as most say)
2) Davis (as most say)
3) Tamaya.... would have been C Plath years ago but the big Tamaya's are georgous!

I used to use a Freiburger (sp?) for daily work but found the Astra handle more comfortable for my big mitts...

Originally Posted by MehmetCan

After spending almost two decades programming computers and designing systems, I know one thing for sure; electronics fail all the time. So which sextants would you suggest for these three usages :

1. Everyday use
2. Emergency use
3. One to be proud of without caring for the price, something for the grand children and etc.

This question probably came to the posts many times, sorry for the inconvenience in advance and thank you all for your comments.

Fair winds and best regards;
Mehmet

[Capt GenlmanJac]

NEVER take on Big Wind and Water unless your Crew has at least as much experience, intelligence and Conservative Values as you. MOST abandoned ships are found bobbing gently up against a sandbar somewhere (S/V Satori, which see.) And to argue FOR some electronic toy... Oh never mind, I got seagull poop to scrub!

[Dockhead]

Originally Posted by boatman61

Luddite 'DUHHH..!!' question... will the GPS phones still operate out at sea.. eg; 200miles offshore..??
I've only just discovered ones with internet...

Yes, they do, but again, 200 miles offshore, why do you care about your precise position? You actually don't - a vague direction is quite ok. Precise position becomes interesting only near land.

[Capt GenlmanJac]

I go on Broad Water cuz of where I DO NOT WANT TO BE, NOT WHERE I AM! I agree with DICK, er DOCKHEAD! When I see some landmass, THEN I will concern myself with where I am... And then only if it happens to be dead ahead...
bt