By Bob Halstead
“Musical Tanks” was a game I played in the pool as a training aid for scuba divers. I learned it at my NAUI instructor course in 1970 when most scuba divers were also experienced breath-hold divers (skindivers). All the divers would remove their tanks but be breathing from them on the bottom. I would then swim down and tap one on the shoulder which meant he (or she) had to give me his regulator and, blowing bubbles, move on to another diver and tap him on the shoulder. So divers were moving from one tank to another. Then I would start removing tanks so that eventually the divers were competing for just a few tanks. If any diver came to the surface, they were out of the game.
The trick to winning was breath control. If I saw another diver was competing with me for a tank I would wait, blowing tiny bubbles, until he took the regulator then immediately tap his shoulder and he would have to give the regulator up, still short of air and usually off to the surface, but allowing me several breaths before another diver tapped me. This was good fun, especially as I got older (and more treacherous).
I taught my pool classes mostly without a tank on. I could demonstrate mask clearing (several times) on one breath after already breathing out a bit to get on the bottom. I blew the water out, but did it gently so no air escaped the edge of the mask. You should try this. See how many times you can clear your mask with one breath of air and no spillage. Half a dozen times with a standard mask should be easy. You will need a weight belt, but should not have any more weight on than if you were scuba diving.
I was reminded of all this by underwater model Leigh Paine, a good scuba diver and professional violinist, when we were shooting promotional shots underwater with a useless violin. We did this without scuba in a pool. She was wearing a concert gown with a weight belt underneath, but no mask, snorkel or fins.
I told her “Just breathe out, sink to the bottom, pretend you are making beautiful music, and I’ll take a couple of shots. I’ll have to wait a few seconds until the surface is calm enough to get the palm trees in the background. Remember to pull the dress down, keep your eyes open and your elbows in, and don’t forget to smile.”
At first she descended perfectly – but then dashed straight back to the surface again. She was breathless far too soon. Evidently there was an instinctive barrier to breathing out, then holding her remaining breath. She was experienced underwater with nearly 200 dives logged, but I realised that she had never played breath-holding games, had never done skindiving and was not trained to hold her breath whether her lungs were full or empty.
Most people never try holding their breath at all, and why should they? But divers will benefit by getting used to the sensation of increased CO2. If you can tolerate the discomfort of a minute or two without breathing, whether you are gently exhaling as you would if you had to make an emergency ascent without air, or whether skin diving to 20 metres or just swimming a length of a pool underwater, this gives you a certain confidence in a situation where you may be unable to ventilate your lungs immediately, and thus avoid panic. If you panic underwater, death is a likely outcome.
So Leigh started to practice some underwater breath holding, soon became relaxed and proficient, and the resulting photo is what we wanted, and perhaps even breathtaking.
Here is a test for you to try; my bet is that you will have to practice. Wear a normal weight belt and snorkelling gear. Dive down to the bottom of the pool and remove your fins, mask
and snorkel, and leave them neatly on the bottom. Ascend to the surface, take a couple of breaths then sink down by breathing out a bit (you still have your weight belt on), put on your fins, then your mask. Clear your mask, blow a bubble ring, put your snorkel in and ascend through the ring, clearing your snorkel underwater with your last puff of air. Arrive at the surface and snorkel without raising your head, without choking and without spitting your snorkel out and crying “help!” In other words, be cool.
If you do not know how to blow a bubble ring, this is the method I use. Lay on your back with your snorkel (or regulator) out and your mouth pointing upwards. The water needs to be free of current and surge – practice in the pool. Make an “O” with your lips and stick your tongue in. Then cough a little air though your lips while moving your tongue back and forward quickly. Just blowing does not work; you have to cough the air using your diaphragm. If the air ring breaks up you have not mastered the technique yet. Keep practicing until you can blow a series of perfect rings – the effect is almost magical – and you will even find that if you blow two in quick succession that the second will move through the first as they rise to the surface.
A word of caution is required. If you practice breath holding or skin diving it is a good idea to have someone around watching you. Deliberately hyperventilating before a dive will extend your breath-holding times and allow you to skin dive deeper, but it comes with a risk. If overdone it can drive your CO2 levels so low that you pass out on ascent through rapidly falling partial pressure of oxygen (O2) This is “Shallow Water Blackout”. Remember, build up of CO2 is the trigger for breathing, not a lack of O2. Without hyperventilation, the build up of CO2 in your body will usually force you to breathe before O2 gets too low.
Here is something you can try at home without getting wet. Practice breath holding and time yourself. Most people can do one minute, far fewer two. Get a friend to write a simple mathematical problem on a folded piece of paper. Something like 27 divided by 5. Take your confident best breath holding time and subtract 20 seconds – normally enough time for you to solve the problem (no calculators!). Have the paper in front of you, hold your breath for the new time, open the paper and solve the problem BEFORE breathing again. You will find it hard – you will want to panic. Now imagine yourself underwater without air and a problem to solve. Are’nt you glad you have some breath control and have practiced all your skills so you do not have to think about them?
Stick around, next time I’ll teach you how to walk on water – but don’t hold your breath waiting.