Rapture of the Deep
Swim Silent – Swim Deep
Where the Fish Are
Delights and Dangers of the Deep
Raymond O. West, M.D., M.P.H.
It’s the good old summer time. And the pools, lakes, quarries and rivers are warming up again. It’s time to take out the SCUBA gear, fill up the tanks, polish up the facemasks, and hit the depths. Millions do it every year from the briny shores of Maine to the lakes of Minnesota, and on over to the Strait of Juan de Fuca (reports have it that the world’s largest octopuses lurk in the depths of the strait!). And, of course, all points south.
There must be a gene for the "I’ve never been there, and I want to go there," imperative that compels mankind to push the periphery. But one doesn’t need to take the Orient Express or join an Everest summit team. For a few feet below the surface of most any body of water lives a new world, the frontier of the depths.
So, in part, that is why there are almost 9 million certified SCUBA divers in today’s U.S.A. They have learned of the delights, challenges and adventures just a few feet under.
And they’ve learned of the dangers. For instance, some time ago so divers drove down to Florida to enjoy the thrills of underwater cave diving. Four men swam into the cave, but none came out alive. Getting lost, they ran out of air. In those last few tragic minutes, the fought each other for a few last gasps of life, and died. No. SCUBA – for all its delights – comes with its own dangers.
Here’s one: It’s called "rapture of the deep," or nitrogen narcosis. Like when the diver takes out his mouth-piece and hands it to a passing fish. A few gurgles and it’s all over. Getting drunk on nitrogen befalls those who go too deep and stay too long.
Just as pertinent is pressure. Remember your high school physics, how at sea level the atmosphere, pressing down from the outer limits, creates a pressure of – say – 15 pounds on each square inch of body surface. That’s okay; the way it’s supposed to be. But sink into the water and, with each foot of depth, the pressure goes up. Now the middle ear, sinuses and lungs are in a squeeze. Fortuitously, the air tank and breathing valve deliver air at a pressure just enough to match the water pressure surrounding the body. Without that invention by Jacques Cousteau, the rib cage would be squeezed as well, and at sufficient depth would be crushed like an egg. Watch out, now – for if a diver forgets to exhale as s/he ascends, the air in the lungs expands and may blow out like a bulge on an old inner-tube. That’s one of the reasons why several healthy, vigorous and fit people die annually from the risks of SCUBA diving.
Like rock climbing, hang gliding and sky diving, SCUBA has its hazards. So, don’t try it without training. Do it safely, and relish that nether-world of delight.
But watch out for those giant octopi in the Puget Sound!
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