A lot of guys in BASS use them. I think the expensive versions are water-activated (I recall a story about somebody's suspenders inflating when he left them in the bottom of his boat during a heavy downpour). I have the cheap version -- you have to yank a cord to inflate (actually, mine is even cheaper than that -- it's worn like a belt, and after you inflate it you have to stick your head through the hole). But since we're going < 5 mph (with a good breeze behind us), I guess that's OK. At least until we get run over by a Tr-22 doing 75!