Originally Posted by MedSailor
Type III, and V PFDs will NOT hold an unconscious person's head above water. All inflatables (that I know of) are USCG certified as Type V PFDs.
I wonder how much of this has to do with proper fit (tensioning of straps) and use of crotch straps. From what I understand, most PFDs, of any type, won't keep you from drowning indefinitely without proper fit and crotch strap. I paid the extra money for the option crotch strap on my Mustang auto inflate.