Celestial Navigation

[sailingdog]

Last I checked, the Russian navy wasn't hunting my nuclear missile carrying sailboat.

[hellosailor]

Cameraderie, any really good Real Navigator (like a Polynesian or Viking) would call your sextant a overly complex unreliable newfangled nonsense, the same way you'd look at a sextant.

You might not find Bermuda or Hawaii (unless you had an am/fm radio onboard and they were still broadcasting) after some despot caused the GPS system to be shut down, but you'd certainly find a coastline and then be able to make your way home without a sextant. Heck, you can see the nighttime skyglow from any major coastal city out at sea before you can see the coast in daytime.

To justify a sextant on the concept that the GPS system might be shut down for the end of the world, is pushing the concept a bit. If the world ends, you'll probably be safe staying at sea anyhow.

Celnav today makes a fine brain sharpener. A fine hobby, just like chess. But the same $300 that will buy a used low-end metal sextant, will buy two GPSes plus rechargeable batteries and a solar charger plus a brick of AA cells that can give you power for daily fixes for six months by themselves.

Drop the sextant, and you've got trash. Drop the GPS, and you've got the spare. With more spares at $100 each.

Celnav is an anachronism today. Like a horse and buggy, it still may be the best tool for a job--may be, some times. And it might make a nice change to take the horse and buggy out for a picnic in the country.

But in practical terms? Expensive, fragile, bulky, unreliable (use it during a 48-hour overcast, go ahead) and requiring a trained user and auxiliary materials.

Nice if you can afford it as a luxury and a hobby, but of little practical OR potential value these days. And that's from someone who has owned them and enjoyed using them.

[sailingdog]

Hellosailor-

I'd like to point out an article that recently came out. It is readable here.
I'll quote the relavant part from it:

Navigation, power and communications systems that rely on GPS satellite navigation will be disrupted by violent solar activity in 2011, research shows.

A study reveals Global Positioning System receivers to be unexpectedly vulnerable to bursts of radio noise produced by solar flares, created by explosions in the Sun's atmosphere.

When solar activity peaks in 2011 and 2012, it could cause widespread disruption to aircraft navigation and emergency location systems that rely heavily on satellite navigation data.

I plan on being out sailing in 2011 and 2012...so I think I'll keep the sextant handy, just in case.

[hellosailor]

Sailingdog-
I'd say the key phrase to that entire article is "Charged particles from solar flares also produce intense bursts of radio noise,"
In other words, noise bursts may knock out your receiver for several seconds or several hours. The same way that a cloudy day will knock out your sextant. But GPS has been around more than 11 years, the problem is neither unknown nor unanticipated, and as long as you are not making aircraft landings during a noise burst, you'll probably have no problems.
Earlier this or last year, there was frantic talk that the world was going to end due to some intense solar flares, that cell phones would be killed, GPS satellites would be killed, tv and powerline networks would overload....Yeah, solar flares have come and gone before and yes, they really could wipe all life off the planet. So far, the news has mainly been focused on selling itself.

[camaraderie]

HelloS...thanks for the support on this again. We're not gonna convince anyone here so I'm gonna drop out of the discussion at this point having said my piece. 90%+ of the people cruising today have no sextant and Darwin is ready for any who choose to do it with sextant alone. If someone wants to do it with both, all they have to worry about is rust on their expensive paperweight. I'd much rather go to sea with 3 GPS's than a GPS and a sextant. See ya on another thread.