I have used it in a real needy situation
:P Little River / Alabama Suicide Run / Rapid: Humpty Dumpty. IV+ I ran the wrong line on this Rapid and spent well over a minute stuck in a crease / Hole up against a large Rock. After about 30 seconds I took a hit off the Rapid Air and then another hit just before being kicked out of the hole and into a boxed in terminal eddy. That eddy kept recirc'g me under a rock shelf. I took two more hits of Rapid Air while waiting on a rescue boater to set up my evacuation from the eddy. I don't know if it saved my life but I do know that it gave me the extra breath I needed so that I could regain my composure, thus allowing me to remain calm and help my rescuers help me. I also know that if you think you can hold your breaths for 2 minutes..think again. Under extreme duress the heart rate peaks and your two minutes quickly become 20 seconds, especially in 45 degree water.