So over the summer I was doing a wreck dive on a boat in the middle of the ST. Lawrence river. The wreck was under the main travel zone of the seaway, so we had to travel underwater a ways to get to t safely. To and from this area was extremely high current, enough where we had to hold a rope. Emergency surfacing in this area is considered to be dangerous because of heavy boat and ship traveling and a nice $10,000 fine if the coast guard has to save you and shut down the area.
I was about 1300psi at around 50 foot when the hose on my gauge blew off. I lost air extremely quickly, and not only could I not suck in air through the regulator, but somehow when I tried it sucked in water. Anyway, kept calm and obviously lived, but there was some issues and I spent quite a bit of time without air. Pretty exiting video, check it out.