So in contrast to the other thread about the flashlight being frozen in a block of ice. I guess this is a little more real world...

http://www.pinnacleflashlights.com/blog/2009/05/16/fishing-with-the-nitecore-ex10-literally/

Video of the Nitecore EX10 functioning at a depth of 10ft. No, it's not waterproof to a depth of 660 feet (because who would really be swimming at that depth?), but I'm confident that if it's in my pocket and I have to swim across a river or something, my light will still be working!