I have never had any problems after accidental immersions of my Photon 2, though I have usually unscrewed it and dried it out before too long. On the photonlight.com website's message forum, Brian Avery has described a way to properly waterproof them and I have quoted him below (though, I haven't gotten around to doing it to mine yet).<br><br><br><br>--- Quote from Brian Avery of photonlight.com forum:<br><br>: what kind of store sells silicon dielectric <br>: grease so i can waterproof my p3? <br><br>I got some good stuff at a local diving supply store. It even came in a small <br>key-chain sized tin (very appropriate, I thought). <br><br>You can probably also find something in the plumbing section of your local <br>hardware store. <br><br>Just look for 100% pure silicone grease. <br><br>-Bryan<br><br>: What exactly do you apply it to on the photon <br>: light, and how do you apply it? I'm just not <br>: familiar with this material or how it's <br>: used. <br><br>Basically, you want to fill the inside of the light with the grease. Cover the batteries completely and around the edges where the battery cover closes. If you want to go all the way, you can even lift up the circuit board a bit and get some of the grease in under the button, but this might be overkill. If you get too much in there, you might have a little trouble with the switches. With mine, the on/off switch was not working reliably and it would turn itself off and reset itself as soon as I let go of the rear button. After working the button for a minute or two the grease got worked around enough inside the case that it was not getting in the way and the light worked fine after that. <br><br>Right now, the light has been sitting in a jar of water for about a month, but I think it is still water-tight. <br><br>-Bryan <br><br>