I have Auroralites safety collars. I live deep in the woods and usually walk my dogs offleash. I also live on a lake. Since I have labs who love to swim, I was more than a little skeptical when I ordered my collars but I decided to try. As soon as they came, I popped in a battery and immediately tossed the collar into the lake and waited for it to sputter and die. Fifteen minutes later, it was still going strong and the dogs and I sloshed out into the water where I RETRIEVED it and put it on the dog. We went for a walk and I could easily see the dogs. As a matter of fact that was two years ago and the collars are still working perfectly. The luxury of seeing exactly where my dogs are at night (of course there are no lights in the woods) is wonderful. During hunting season, I no longer worry because there is no game with glowing blue stripes around their necks so my dogs are protected and highly visible. Because of that we can actually go for walks in small game season and that is pretty terrific! All this and even when my dogs go for a swim!!!! THREEDOGLADY Beaver Lake, N.J. , 06/03