20 / 116
Pollock tells me about research that was done on
commercial divers in the 1960s and 1970s, when
many occupational divers were experiencing dysbaric
osteonecrosis. This condition involves lesions of dead
tissue in long bones such as the humerus (upper arm)
and femur (thigh). An extensive monitoring program
of North Sea divers led to changes in diving protocols
that resulted in a reduction in the frequency of cases.
Three factors were identified as important risk factors
at the time: a history of repeated dives below 165 feet,
a history of DCS and a pattern of diving profiles that
could be considered experimental. That sounds much
like technical diving today, which is the reason Pollock
started this study. We tech divers are an odd lot,
participating in an edgy aquatic experiment with our
bodies over time.
The battery of tests, which lasts for two hours
after each dive, includes collection of blood for
microparticle analysis (cell fragments in the blood that
could show signs of decompression stress), collection
of DNA samples for epigenetic study (analysis of how
stress factors can reprogram gene expression) and
testing of lung function.
The tests also include questionnaires about our
dives. Were we comfortable? Were we using active or
passive heating? Was our exertion level high or low?
For me, the questions bring insight and revelations
about my personal diving protocols. I have always
assumed that a warm and cozy diver would be a safe
diver, yet my active heating efforts could be promoting
increased ongassing of inert gas during the deepest
portions of my dives. As I chill during decompression,
relatively still in the cold meltwater, I might not be
offgassing as effectively as I thought. Or perhaps my
additional exertion when taking photographs means
added decompression stress. Diving with me is like
walking a dog. I swim laps around my subjects to
get a shot, shifting my vertical position in the water
column while panting and handling heavy camera gear.
I suppose it’s no surprise that my hardest photo and
video dives netted the highest bubble scores.
One might ask how Pollock’s research could ever
result in valid conclusions if every dive is such an
uncontrolled mess of variables. It might be tough
to publish, but the value of his mission goes far
beyond a published article in a scientific journal. His
most important work may be to reveal to the diving
community that even if we feel great and follow what
we believe to be a conservative algorithm, we may
still face risks now or later in life. His questions and
careful observations create a framework for education
and discussions in the technical diving community.
We really don’t know a lot about our experimental
technical dives, but if we can push for more research
in this field, we should be able to improve our
understanding and safety in the future.
I’ve emerged from the heart of Bell Island with an
indelible image in my mind. My downward-facing
heart-valve mermaid is strong, but I don’t want to
see her navigating a field of bubbling blood again. I
know I need to make some changes that can reduce
my decompression stress. I’m going to re-evaluate
how or whether I choose to use active heating on
cold-water dives. I’m going to add more light exercise
to my decompression hangs and lengthen my last
decompression stop. I hope that with more of this
cutting-edge research we’ll acquire better data to
enlighten our community and usher in a set of
safer protocols.
INTO THE MURKY DEPTHS
The chocolate-brown water yields to a wispy veil of
vaporous white. A dive light casts a warm glow in the
distance, and I emerge into clear water that reveals a
17-foot-high tunnel with squared-off walls. A pair of
rusting metal pipes covered in gelatinous silt lures us
deeper down the shaft, and a hulk of gears and wheels
takes form in the dark room ahead of us. We find a
large pump system and a junction of broken pipes
and gear. Cas Dobbin, an engineer in the oil and gas
industry, looks around at the equipment, noting the
broken valves and severed connections. He files away
18
|
SPRING 2016
DIVE SLATE
BELL ISLAND MINE
Neal Pollock examines expedition diver Steve Lewis using 3-D ultrasound. Jill Heinerth swims
down a mine tunnel, documenting artifacts. Cas Dobbin photographs the SS
Saganaga.
JILL HEINERTH
CAS DOBBIN
JILL HEINERTH