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The ONLY important features on a compass are the needle/card and the index line. Everything else is a convenience. Quit worrying about a convenience feature. (IOW - carry a flashlight and "recharge" the "glow-in-the-dark stuff" as required - tactically.) Tritium is a radioactive isotope with a useful half life (about 10 years IIRC). After that it gets progressively dimmer as it continues to decay (that's what radioactive isotopes do). FYI - there are compasses in the supply system that are older than any of the 18Xs on this board. Some of you will probably get them issued. No supply "person" worth its salt is going to throw a compass away just because the tritium is a little feeble. In fact - because they are important to mission, etc. they are rugged enough that running over them with a tracked vehicle will not reliably destroy them (but you can still be charged for damaging gov't equipment). The important stuff - After you get your issue and before you start land nav your cadre will give you the opportunity to check the compass for accuracy (w/i 2-3 deg E/W of Mag N at a surveyed point). Check it all the way around (360 deg) to make sure any error is consistant, log the error, and move out. If the card does not rotate freely, the error is more than 2-3 degrees, or it's half full of water from the last student's swamp crossing (the one he quit on - otherwise it probably would have had time to dry out before they issued it again) then you approach the cadre and (respectfully) DX your compass. BPT articulate your reasoning. I don't know about today but "weak tritium" didn't use to elicit sympathy.
(Standard disclaimer - this info is dated and based on my personal experience, opinions, and prejudices - I'm now retired and only good for crusty opinions. If anything has changed significantly your cadre will advise you. Obviously what they tell you is the "truth du jour" and superceeds anything else you might have heard/imagined!)
FWIW - Peregrino
And NO the compass housing is not filled with tritium gas. The DOE/NRC would have cows. It's sealed in glass vials. There's usually a phosphorescent "paint" under the index line that is sufficient to read degree markings. It will require the flashlight at regular intervals to get quality illumination. If you use the rotating bezel with its tritium vial on the index line and count the clicks the way you have been/will be taught you do not need to see the degree markings on the compass card. The real compasses can be identified by the DOE warnings/disposal instructions on the back of them.
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