today’s regulators are designed to fail wide open, as in free flow. Still plenty of gas to get to the surface. Again, with proper situational awareness and ridged equipment maintenance, there is no reason to have an out of air situation. Now, if your doing something stupid like diving beyond your training or equipment configuration.....can’t help ya.
My Own Out of GAS Experience
This is the only time I've ever heard of a first stage failing shut. Anyone else? I have to ping Graham to ask if when he took it apart and figured out why it failed shut. An extremely rare occurrence as far as I can tell.