Imagine that you are swimming peacefully underwater. Fish swirl around you in an ever-changing rainbow of color. Light filters from the surface and shimmers silver patterns on the white ocean sand. You are in your own world, calm, relaxed and . . . sluurrrp, out of air! Where's your buddy? No, really, where's your buddy? You look for your dive companion and his alternate air source, and realize that he is no where near you. Perhaps he is off flirting with a turtle, or maybe he just swam away to check out an interesting coral head. Whatever the case, he is too far for you to reach his alternate air source in time. What do you do?
Obviously, a diver in this situation needs to make it to the surface. Instead of panicking and shooting up in a dangerous, fast ascent, a skillful diver would swim safely to the surface using a Controlled Emergency Swimming Ascent (C.E.S.A.). He does this by swimming slowly to the surface while exhaling and deflating his buoyancy compensator. Every certified diver learns the C.E.S.A. in his Open Water Certification Course, but most divers forget the skill because it seems complicated and is not practiced regularly. Here is a step-by-step guide to the C.E.S.A., an important emergency management skill that every diver should master.