One of the frustrating things about being labelled a technical diver is the image of technical diving as being only for hardcore, extreme exploration. Yet technical diving is something that every sport diver should consider simply so that they can improve their own safety underwater.
Sport divers seem to have the perception that so long as they stay below 40 meters and within no decompression limits, they are safe. Yet when one looks at statistics (such as those published by BSAC http://www.bsac.org/uploads/documents/Diving_Safety/incidents/2007_Annual_Report.pdf) it becomes clear that it is the sport divers and not the technical divers that carry the highest risk. A look at the statistics shows firstly that the majority of the incidents taking place do so below 30 meters. Secondly, the statistics seem to indicate that a lack of basic skill (specifically ascent rate) are to blame.
These trends tend to enforce my personal experience of sport divers (garnered over 15 years, ten of those as instructor). Once sport divers acquire their open water 2/ advanced certification, they tend to think they are invincible and can do any dive… so long as they stay within the no decompression limits. The introduction of dive computers has not assisted, with divers simply strapping on a computer, grabbing a cylinder of air and going where they please.
This attitude was highlighted recently when I heard about an experienced PADI instructor (with no technical qualifications, so limited to 40 meters and using a single tank and air) who was proudly advertising a weekend excursion to Wondergat (one of South Africa’s inland dive sites with a fascinating cavern that starts at 40 meters and extends back about 100 meters to reach a total depth of about 60 meters) where she took not one, but three students to the back of the cave (60 meters and requiring a 100 meter swim with a descent of 30 meters), on air. Because of its depth this dive is a normoxic, Intro cave dive and most definitely not a deep air, advanced diver dive.
Now as a deep air diver myself I can hardly point fingers, except for one thing, my deepest ever deep dive on air was to 65 meters and I never, ever go deeper than 50 meters without weekends of build up. I also never, ever go deep on air without twin sets and staged bail out. Their dive was on single cylinders. They had placed a single bail out cylinder somewhere on the way up. Much good it would have done them if they had needed it. The swim out of the back of the cave is hard, especially if you are panicked, have lost a light and destroyed the visibility. The instructor thought she knew what she was doing because she was an instructor. They all came back, which just enforces their perception that they are brilliant divers and that this is an easy dive, well within their capabilities. But they were lucky. That exact same dive, under exactly the same circumstances (except that the instructor was actually technical trained and experienced) killed himself and his student. The student panicked and ran out of air at the back (they were on singles, it was dark… and deep). The instructor assisted, but they never made the staged bail out and ran out of air on the swim out..
Sport diving is only safe if you do not break the certification limits. If you want to go deeper or stay longer you must have a course such as Advanced Nitrox. If you want to become more self reliant and to reduce your risks on sport divers than you should definitely do an Advanced Nitrox course.
In my next post I will go into the basic skills that you need to safely explore the so called ‘sport’ (40 meters) zone underwater.