rick is right. Test it out. Some years back I had a fiasco when I tipped over my 12' boat coming into a landing at a small local lake. Stearns self-inflate vest didn't. Pulled the cord, nothing. Like a dummy I forgot there was an inflate tube and ended up using the boat as my preserver and kicking myself to shore. I found one winter would cause the CO2 cylinder to empty and you were without inflation. Happened next year when I tested it again. Now I don't trust them and wear a mesh shouldered buckled vest. I should tell you the rest of the story.

When I tipped the boat over it was because I lost balance trying to clean the weeds from the trolling motor in the dense milfoil at the landing. A Park Ranger saw this and put out the call for help for an old guy drowning. About the time I'd kicked the boat in to where I could stand the cavalry had arrived and two guys in full survival gear grabbed me and put a life ring around me and another pulled me to shore while they took over the boat, which was floating with about 6" of water in it. By the time I got to shore there was a fire truck, an ambulance, two police cars, the fire station rescue truck pulling an inflatable boat, and about 25 people from around the park all spectating. The landing I'd fallen in was a soup of slop and by the time I got out I was hanging from top to bottom with green snot and weeds and looked like the swamp monster from a horror movie with a long green beard. The nice part was the healthy young rescue guys dumped the boat, carried it up to my trailer and tied it down, and the guys in the ambulance wouldn't let me leave until my blood pressure and heart rate were within their required "safe" range. When I got home (only a few blocks from Golden Pond) my wife took one look at me and said, "Yep, we were just talking about hearing all the sirens by the lake and wondered if it involved you. It looks like it did."

By the next day, even tho I immediately showered very thoroughly, I had about a thousand red spots all over my legs. I'd been wearing shorts and kicking in all that slop and something left me looking like I had measles. Fortunately, with all that mess on my legs, it didn't itch at all, thank God for that. When I went into work the next Monday a guy at our break table worked for a local Volunteer Rescue Squad and was laughing about the story going around about the old gray beard they had to pull out of Golden Pond and what a mess he was. I had to push him to see how much the story had grown, and of course by this time I was half dead when they got me instead of just about pushing the boat in by myself but sure got the super razz when I 'fessed up to being the "old gray beard" they rescued. I did have a couple of nice bass and a big northern on the stringer and enjoyed eating them even more than I normally would have.