Using sextants on land?

[blackdog]

At sea, a sextant is a good thing to have if the GPS receiver stops working for some reason. But would the same solution be feasible on land as well, when hiking?

If so then there's this clever mini sextant i could use for a sail&hike project. It has no moving parts and only weighs a couple of grams.

[chief]

don't forget you'll need a good distant horizon for a sextant to work. that won't be possible in mountains, forests, etc. maybe a desert? also, you'll need clear skies, a decent compass, an accurate timepiece, a way to accurately determine your altitude (and the horizon altitude), a celestial almanac, maps and a good working knowledge of sight reduction math. any variance of the above and your sights will be miles off (probably 100s of miles). i suppose you could use a nav. calculator to do all the sight reductions, but then if you're gonna do that, why not just use a gps. NO, a sextant is not very useful while hiking. a good compass and maps are all you need. if you want to learn celestial navigation, you need to be at sea where you'll at least have a true horizon and consistant altitude to work with.

btw, i made a living on ocean going ships for 26 years. while i was an engineer and not concerned with navigation, i was interested enough to buy a sextant and learn to use it. early on in my career, the sextant was the primary means of finding your way across oceans. i've long since forgotten most of what i learned.

[blackdog]

I know it's kind of a stupid idea, but I need to have some kind of backup, for the sea at least. Electronics are great (I need a GPS, a digital camera and a computer to do my work) but they can screw up pretty badly at times too. So I have no choice but to learn the theory.

A map and a compass should indeed do on land, and yet I can't help wondering...

Just for the trivia of it?

[chief]

hey, learning to use a sextant can be lot of fun! definitely a good idea for a boat. one particular ship i was on, the deck officers, cadets and i would all take our sights individually, calculate our positions, plot them on the chart and use the satnav (pre-gps) to see who got the closest. it was a voyage long competition which i actually won once or twice. can't see it happening on a hike, but it sure can give you an extra measure of confidence on a boat. enjoy!