The new Spinlock auto-inflatable Deckvests seem to be enginered to take into account a broad range of the previously mentioned concerns (although no one product will address every worst case scenario), but they're not cheap. They are very strong, light weight, and have lots of features. Some might prefer a simpler approach though.
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Yes I was looking at that model. It is truly amazing. Can anyone find anything negative about it. I sure hope someone can trash it other wise I will be tempted.
The risk calculation changes with a unit this good. My cheap standard vest is guaranteed to work all the time because it has no mechanism to fail. The Spinlock however will keep my face up and has the spray hood which would be better if unconscious or in rough seas.
So what is more likely, being unconscious or the mechanism not working? I suspect being unconscious is more likely as everyone has said the mechanism is well tested for a long time.
But as someone said fixed flotation can not deflate. So I wonder if the Spinlock would remain buoyant for three days until I either was rescued or died of thirst.