Paragraph 2.2 begins the UK Civilian Experience.....and cites the 1995 CAA Study. What is quoted there is not very flattering. Look where we find ourselves today....18 Years later.
http://traktoria.org/files/helicopte.../AG-341-02.pdf
Comments that support Griffo's fondness for such kinds of Breathing Systems....
They concluded that HEED had facilitated underwater escape. They reported that there were 25 individuals who reported that they would not have survived without an emergency breathing system. EBS users consistently reported a calming effect replacing the post-impact panic frequently experienced with the initial in-rush of water.
So much so, that the Marine Corps were seriously considering training their ground troops and supplying units to those proceeding on over-water missions.
Like the soon to come into service Canadian design, the US Navy was modifying the system so that the compressed air bottle was an integral part of the vest. An air hose was added so that only the regulator / mouthpiece need be located, retrieved and placed in the mouth.