Sextant fanatic

[Jacket]

<you'd soon eat the batteries in your spare handheld GPS.>

Why would you? If you're far enough from land to be able to use the sextant safely, you'd only need to turn the GPS on briefly once or twice a day to get a position fix.

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[AndrewB]

Yes, didn\'t Les Powles ..

... make it back that way from somewhere west of Cape Horn to Lymington, when his main GPS died?

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[tome]

Sod's law tells me I'd forget to switch it off at some point, as witnessed by my old hand-held which always has flat batteries when I try it out.

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[zvidoron]

This is a wonderful thread

I read every entry and really enjoyed myself!

An excellent book to read is David Burch's (Starpath school of navigation, USA) "Emergncy Navigation". It is full of excellent advice on how to navigate without various items and with nothing at all. His best piece of advice is to buy a very good mechanical wrist watch, set it to UTC and wear it always, so if anything goes wrong the watch stays with you. I have a 30 years old Omega Seamaster that does the job wonderfully.

As long as GPS or Radio are functioning you keep a daily check on the watch so you have a very accurate idea on its rate of change (Garmin GPSs are about 1 second behind UTC on the display). If all things go down you can keep applying the right correction daily.

Sextants are actually surprisingly accurate if maintained properly and their errors adjusted out. I tested quite a few in the last year. German metal sextants, from expensive Cassens & Plaths to the small Freiberger Yacht Sextant, used from a stable platfrm with the Sun brought down to its reflected image (to remove variation of horizon, sea state etc.) invariably give repeated position lines well within 1/4-1/2 a mile from actual GPS position. Even cheap Davis 15 and 25 plastic sextants give an accuracy of 1 1/2 miles or better. Obviously sea conditions will introduce variation and this is where averaging 5-7 sights helps a lot.

There are various perpetual almanachs which are small and give accurate enough GHA and Declination so a full alamanac is not needed in emergency.

Using either sight reduction tables or Haversine tables it takes minutes to reduce a sight. I reduce several at once which cuts time so within 15-20 minutes I have 5-7 position lines and imediately see if I made an error in one of them.

DR is of course the basis to it all - read "The Lonely Sea and the Sky" to see what a master like Francis Chichester managed to do with excellent DR coupled with ingenious use of Astro Navigation.

Yes of course GPS is the answer to every navigator's dream and I have used it several times to get out of difficult situations in the air and on the sea. But there is no substitute to the feeling of acheivement that comes from mastering a wonderful art like celestial navigation.

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[Reap]

To me it depends on wher your going, not much need for a sextant crossing from solent to Cherbourg for instance even without GPS. If you are a traditionalist then your traditional nav will be up to speed then no doubt.
However no harn in carrying one and it can be of use in coastal nav if you can be bothered.
For an ocean crossing though I would certainly want one with me and would probably use it too, just for the pleasure of navigating (properly)

Now don't get me wrong I am no luddite and use gps, however I like to use trad nav and think it would all become soulless if you take electronics too far.
After all you can link your gps to your auto pilot and let it do the whole trip for you without even coming on deck. Whats the point??? You might as well get the ferry or fly!!

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