Dave
Might not fit exactly what you mean, but whilst diving with a relatively inexperienced diver who had just bought some 'new' 2nd hand kit, at the Farnes recently when he suddenly grabbed my pony reg. Cheeky Bas***d I thought, use your own air, and he had loads, I could see it on the guage 80 bar plus. At the surface, including stops, he explained that his guage had jammed and he was out of air.
The problem I think you will find is that only dead divers have a problem with equipment without a form of redundancy. The rest of us only have a tale to tell.
