I own 6 Cabelas 3500 series inflatables. I wear them in rain, snow, ice, freezing splash, you name it. I've never had one go off as a result of being wet due to moisture or rain.

I was fishing a tournament last year in Alpena with Skillet007. A storm came up in the last hour of the tournament. We actually took a rouge 7 footer over the back of the boat. After we hit the channel for weigh in, the storm dumped over an inch of rain in less than 20 minutes. I was still wearing my life jacket when we jumped in the truck after getting everything tied down. And it did NOT inflate due to being wet.

One thing to keep in mind. Check your state regulations in regards to inflatable life preservers. Some states (like Michigan) have since updated their code book to allow inflatables to count as a PFD if it is NOT being worn. I do know that some backwards places have YET to follow the federal guidelines and still require the wearing of an inflatable for it to count as a PFD on board.

Federal law (USCG) simply goes by classification (Type I, II, or III) and all new inflatable are labeled as such. State law can be more stringent and some of them "specifically" state that they must be worn to count. Keep in mind that USCG cannot enforce state laws so they will only go by federal law which allows them to count towards your needed total.