I worked for 5 years, and part of my job was inspecting, maintaining, and making emergency repairs on underwater hydraulic and electrical systems aside from the structural work. Running out of air in recreational diving is one thing, but in the tight, dark spaces of a cave, or under a moving piece of machinery it is another.<p>The one guy, Huotarinen, in the article died while trying to switch mouthpieces, and he was an experienced cave diver, not recreational diver.