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WBM september 2010
with the respect afforded to anything weigh-ing
in the vicinity of 250 pounds, with double
rows of razor-sharp teeth. One observer, Robert
D. Decker, writing for Scuba Diving magazine,
referred to them as “Barney Fife in Arnold
Schwarzenegger’s body.” Decker also noted
that “Barney always carried at least one bullet,”
so divers shouldn’t get too cocky around these
beasts.
Two of them had moved in slowly behind
Mobley, as the occasional blink of her camera’s
flash lit up the water, all the way to the surface.
The sharks kept edging into the periphery of
Mobley’s sight, making her aware of them and
distracting her from her work with the camera.
“I finally got so annoyed,” she said later,
aboard the dive boat, “that I turned around and
snapped a picture of one of their eyeballs.”
█ The Basics
Sharks are actually quite low on the list of
things that one needs to consider when decid-ing
whether to seek training and certification
as a scuba diver, which can be accomplished
locally at any of three area dive shops (more
information on these later). A more important
consideration, to the point of being tested on
the subject as a prerequisite to dive certification,
is the absorption of nitrogen into your tissues as
you descend into deep water and its release as
you surface.
Normally, the air you breathe is about 79
percent nitrogen, which is absorbed and released
in your body all the time as you breathe. The
increased pressure of water at various depths
causes the nitrogen in the compressed air you’re
using to breathe underwater to become absorbed
into the body’s tissues in higher than normal
concentrations. In and of itself, this absorption
of extra nitrogen is not a problem. However,
that extra nitrogen you’ve absorbed, reacting
to the decrease in pressure as you surface, cre-ates
micro-bubbles in the bloodstream. These
bubbles can be exhaled safely through the lungs,
as long as you don’t ascend too quickly. A rapid
or uncontrolled return to the surface can turn
those bubbles loose into your tissues or organs,
causing what’s known as “decompression sick-ness,”
or DCS. In its milder forms, DCS can
cause aches and pains in joints or tendons. At its
worst, it can be fatal.
The rate of nitrogen absorption-and-release