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pocket compass

Started by oded kishony, July 08, 2009, 04:10:06 PM

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oded kishony

Anyone have a recommendation for a good pocket compass or what features you think one should have?

Thanks,
Oded Kishony

okawbow

Here he lies where he long'd to be;  
Home is the sailor, home from the sea,  
  And the hunter home from the hill.

AdriftAtSea

i like the Iris 50 hand bearing compass
s/v Pretty Gee
Telstar 28 Trimaran
Yet we get to know her, love her and be loved by her.... get to know about My Life With Gee at
http://blog.dankim.com/life-with-gee
The Scoot—click to find out more

Lynx

I have a Kayak compass as an emregancy standy by and handbearing.

I recomend dual purpose.
MacGregor 26M

s/v Faith

Quote from: okawbow on July 08, 2009, 05:45:07 PM
I like the military style lensatic compass.

http://www.thecompassstore.com/military27.html

I agree, but then I used to teach Land Nav.  I would however hold out for one with tritium.  I probably have half a dozen compasses.  I like my Nikon bino's for shooting bearings, but would not want to try to steer by them...  :P

  I also have a Weems & Plath hand bearing compass.  It has tritium, and works pretty well (don't know if they are available like that any more). 

  A true tritium military lensatic compass is good gear.  It would be marked with "National Stock Number: 6605-01-196-6971. Mil Spec: MIL-PRF-10436N" don't waste your money on the copies, they are no where near as good.
(although the one in Okawbow's link looks like the same thing minus the tritium, and I would take that one if I could not find the tritium.)



Satisfaction is wanting what you already have.

oded kishony

Thanks for all your sage advice!

Oded

okawbow

I'm not sure if the tritium is the same thing.....but a freind was stopped at the US border crossing, because my military surplus lensatic compass set off the radiation alarm. By the way; the tritium coating lasts 10 years. So, the older compasses don't "glow" in the dark very well.
Here he lies where he long'd to be;  
Home is the sailor, home from the sea,  
  And the hunter home from the hill.

s/v Faith

  Yes, it is radioactive.  Will set off sensitive equipment, but well worth it compared to trying to hold a flashlight on it (especially if you were trying to steer by it).

  The 10 year life span is correct, but kind of misleading.  It does loose intensity over the years (like an LED does) but should remain visible for some time beyond that.  I have tritium sights on my Beretta.  They are something like 15 years old and can still be seen at night even if they are not as bright.
Satisfaction is wanting what you already have.

Rick Westlake

Tritium is the radioactive isotope of hydrogen, and it has a half-life of 4500±8 days according to the National Institute of Science & Technology - roughly 12 years, 4 months.  Its nucleus has one proton with two neutrons, and it decays into helium-3 (two protons, one neutron) by emitting a high-energy electron from the nucleus. This activates a fluorescent chemical, which emits visible light.

After the "half-life" point, there's half as much tritium as there had been when the compass was new; so it will be about half as bright.  After two half-lives, it'll be 1/4 as bright ... and so ad infinitum.

Quote from: okawbow on July 09, 2009, 06:29:12 PM
I'm not sure if the tritium is the same thing.....but a freind was stopped at the US border crossing, because my military surplus lensatic compass set off the radiation alarm. By the way; the tritium coating lasts 10 years. So, the older compasses don't "glow" in the dark very well.

Chattcatdaddy

So basically they just glow in the dark! ;D
Keith
International Man of Leisure

s/v Faith

Quote from: Chattcatdaddy on July 30, 2009, 11:35:31 PM
So basically they just glow in the dark! ;D

  Yes, but the cool part is you don't have to expose it to light to 'charge it up' first.  You can pull it out of your pocket at 3am and see the card clearly.
Satisfaction is wanting what you already have.