On June 25, 2013, I was interviewed on CBC Radio's Early Edition program. The topic was dive safety and learning to dive in the cold, green waters of BC.
I was invited to go on air shortly after a dive incident at Whytecliff Park, the most popular dive training site for group dive instruction. I knew few specific details about the incident at the time of the interview. What I knew was that a 17 year old woman was training with an instructor (course unknown, dive shop unknown, group size unknown) on June 22nd and was taken to hospital unconscious and unresponsive. She was recovering in hospital. No diagnosis of the specific medical issue was provided in the police report that I had been sent.
After the interview, I subsequently learned that the student had vomited into her regulator, probably barfed it out of her mouth, and aspirated water into her lungs. It was therefore likely a near-drowning incident.
In my opinion, it is very likely that the student suffered vertigo underwater, which can happen when a diver becomes disoriented in a low-visibility environment or has incurred an ear injury owing to a failure to equalize. I had been diving at Whytecliff the day before the incident. Conditions there on June 21 included a plankton/algae cloud that was 15m deep....meaning that there was zero visibility between the surface and 15m. Any diver within this cloud would not have been able to see the surface, the bottom or any other diver beyond arms reach. When this happens, disorientation can cause a diver's stomach to turn, inducing vomiting. This can also lead to a panic response in a novice diver. The risk of this kind of incident is very high in the Summertime, when visibility is poor and there are many students taking group dive classes in shallow water.
I have experience with this problem and have had a student of mine suffer vertigo in the past. Fortunately he was able to suppress the vomiting until we had made our way to the surface.
In teaching the Open Water course, I always advise students of the risk of vertigo and what to do if they feel like vomiting underwater: Keep/hold the regulator in your mouth.
The regulator's exhaust valve is a one-way valve. Nothing that is exhausted can come back in, and when you inhale, the reg delivers air to you normally. You can cough your guts out into a regulator without getting a drop of water into your mouth.
To listen to the interview, click on the link, click the green button to listen to the June 25 episode of the Early Edition and drag the slider to 1:02:00. Then sit back and listen to the rock star…..errrr, I mean sea star.
Mark
http://www.cbc.ca/earlyedition/pastepisodes/