Decompression Tactics
All divers need to decompress
properly. This includes recreational divers doing deep safety stops and
ascending slowly. The benefits of a slow depressurization can be seen by
a simple experiment. Take two soda bottles side by side and open one very
slowly and the other one rapidly. Notice that the one with the rapid
decompression results in more bubbling.
In addition to the rate of
decompression through the stops and making sure enough pressure is kept on the
diver during decompression, divers can also speed up their off-gassing (as well
as in-gassing if not careful at depth) by doing very super mild movements.
We hesitate to call it exercise because that makes it sound like work must be
performed ... which is exactly what a diver does not want to do.
Performing work or exercise will generate micronuclei and make decompression
worse. Instead, very slow and ultra gentle movements are desired, such as
bending the arms and legs slowly. It is the change in muscle form that
will open up capillaries and make blood flow occur and result in better
off-gassing due to the increase in blood flow. But again, anything more
that amounts to activity can generate micronuclei and make things worse ... so
always error on the side of caution by doing ultra gentle movements
The exercise that some divers think is helpful during decompression is a big
no-no.
Another procedure a diver can perform to reduce
decompression risk is to obviously spend more time decompressing. But the
point of this article is to suggest and explain procedures that a diver may not
have thought about. Another of these procedures is for a diver to remain
on their final decompression gas for a period of time after surfacing (in
addition to avoiding anything other than mild activity). This will assist
with the elimination of gas whether bubbles are present or not. But
assuming a proper conservative decompression was done, bubbles should not yet
really be present. Bubbles take time to generate after a dive (but this
may differ with mandatory decompression stop dives). The reason for this
is that it takes awhile for gas leaving the tissues to randomly bump into a
micronuclei. As the micronuclei grow and provide a larger surface area,
the rate of gas bumping into the micronuclei increase. If bubbles are
avoided upon the initial surfacing, then there will be a window of time in
which the diver can increase gas elimination by breathing a decompression mix
at the surface before the bubbles grow - which in turn will reduce
decompression risk. But again, even if bubbles are present, this
procedure will still assist in a diver eliminating gas.
