I'm a little suspicious of automatic devices.

I've seen people try to swim with a life jacket on in ideal conditions. Even tried it a few times. Given a little wind and a little current that life jacket makes you pretty much unable to do more than go along with the flow. Even a short swim against these forces is exhausting.

There are also those rare cases when life jacket inflating on its own might be a catastrophe. I've not researched all the available literature but clearly remember several non-fiction accounts of people on yachts experiencing trouble when the boat turned turtle and they had to swim down and out to reach free air. In one case the sailor wasted valuable time and energy trying to swim out with an inflated life jacket on and was forced to resurface in the overturned hull and remove the jacket. In another case the jacket inflated after they cleared the hatchway and it got tangled. The sailor lived because he was able to remove it.

Yes, I know, this is right up there with people not wearing a seat belt so they don't get trapped in a burning car. A rare situation that sounds more plausible than it really is.

Except I'm not advocating not wearing a life jacket. Fact being that the vast majority of the time it is going to do you more good than harm. What I'm asking for is a life jacket that has a mechanism for disabling the automatic inflation, an oral inflation tube, and some way of deflating a jacket quickly.