On Fri, 27 Nov 2009 20:17:17 -0800, "Bill McKee"
wrote:

http://gcaptain.com/maritime/blog/cold_water/

What happens when you enter the coooold water.


I have had first hand experience with all of phase one and part of
phase two. The descriptions are entirely accurate. Fortunately I
was able to get out of the water by part way through the second stage.

You Can’t Breath:

The first phase of cold water immersion is called the cold shock
response: It is a stage of increased heart rate and blood pressure,
uncontrolled gasping, and sometimes uncontrolled movement. Lasting
anywhere from 30 seconds to a couple of minutes depending on a number
of factors, the cold shock response can be deadly all by itself. In
fact, of all the people who die in cold water, it is estimated that
20% die in the first two minutes. They drown, they panic, they take on
water in that first uncontrolled gasp, if they have heart problems –
the cold shock may trigger a heart attack. Surviving this stage is
about getting your breathing under control, realizing that the stage
will pass, and staying calm.

You Can’t Swim:

One of the primary reasons given by recreational boaters when asked
why they don’t wear a life jacket, is that they can swim. Listen up,
Tarzan; I swam for a living for the better part of my adult life, and
when the water is cold – none of us can swim for very long. The second
stage of cold water immersion is swimming failure. lacking adequate
insulation your body will make its own. Long before your core
temperature drops a degree, the veins in your extremities (those
things you swim with) will constrict, you will lose your ability
control your hands, and the muscles in your arms and legs will just
flat out quit working well enough to keep you above water. Without
some form of flotation, and in not more than 30 minutes, the best
swimmer among us will drown – definitely – no way around it. Without
ever experiencing a drop in core temperature (at all) over 50% of the
people who die in cold water, die from drowning perpetuated by
swimming failure.