I have the suspender type floatation vest that has both a pull cord and also will automatically inflate if the activation "pill" gets soaked. I have never had it inflate while in my float tube or while in a heavy down pour that lasted all day. I wear every year in Alaska and it is always raining there. It goes on over my rain coat.

I also wear it whenever I am in my drift boat or while out in the ocean in the power boat. I was recently fishing with a friend -- we each had small prams. He had a conventional life jacket and didn't want to wear it. Long story short, he fell out of his boat -- life jacket floated just out of reach. Fortunately, his boat floated a little bit and he could hang on to it -- and no harm done. He won't make that mistake again.

If I am wading in deep or difficult water -- it is on.

Doesn't seem to interfer with my set up which is usually a chest pack..

I have had it inflate while I was not wearing it and it was lying on the floor of my boat and it was raining so the rain could enter into the activator but it would not have happened if I had been wearing it.