Lumapower and Water

I have searched here and on the marketplace for specific information about Lumapower and their waterproofness and/or resistance. I read that they are tested to 1.5 meters with the threads heavily lubricated. I was wondering what the duration of the test is? Also, is it the threads being heavily lubricated or the o-ring that is really keeping the water out? Basically, I'm wondering if it can put up with what I can put up with. Is a week in the rain going to kill it? How about a swim across a river in my pocket? I'm asking about the brand in general, but specifically the 301 and 303. I now have one of each (ok, one was bought for someone else, but I played w/it) and I'm consistently impressed w/the lights. Actually, I've found its even very appealing to non-addicts, which is always a plus, and part of the reason I ask this question. Before I start giving them as gifts to waterfowl hunters, I'd best know if they'll survive the blind, or worse three months of being lost at the transom of an aluminum boat in the winter.

Thanks in advance to whomever addresses this!

The M1 tail switch doesn't look waterproof to me.

I think NovaTac claims to be waterproof. It's possible some SureFire's may be rated to swim. Don't know about any others in this form-factor.

I own both the 301 & 303. Both performed well on a wet long weekend camping trip.

I wouldn't use it as a dive light but I wouldn't worry about them in the rain.

YMMV

Thank you both for your input!