This text is not a recipe for deep dives, but simply how I did it and
(possibly) how it turned out so favourably. You will note that I did not
mention ascent rates (critical), where the deep stops were (critical), also I
didn’t mention any mix values or the stop depths/ times themselves.
Extreme deep diving successfully is a complex business. Its not really a
competitive sport, in fact you are competing only with yourself…and if you
lose, you lose the farm.
Since completing this deepest solo dive, I received numerous emails, mostly
well wishes, but a few from would be “Extreme Explorers” less impressed. A few
mails were from Explorers angry with me for not sharing information. My purpose
for attempting this deep dive, was to find some answers and prove some theories.
Deep Explorers who are only interested in going on previously trodden ground,
are not explorers but thrill seekers. If these divers want thrills then…diving
with an un-proven ascent plan is as thrilling as anyone could want! If people
would like some tips on deep diving then of course I am happy to help in a
professional level, the information I have at the moment has commercial value,
and I will treat it as such.
Divers at Explorer level will either be diving in un dived areas of sea, or
diving in unknown areas of physiology. The latter category have over the years
proved again and again what does not work, but still many are willing to embark
on virtual suicide missions believing that strength or fitness rather than
technique, will somehow over come the physical brick walls of extreme deep
diving. I have always tried to embrace new ascent solutions, but these can be
every bit as precarious as the old school techniques.
From what I read of previous deep dive accounts, they all seem to follow
similar themes. Dropping to maximum depth like the US dollar and then ascend
like a jet fighter on afterburner. I thought this was wrong the first time I
read it, a rapid ascent would ensure problems for later, but also, from my
previous experience, too long spent in deep water would need serious redress
also and could cost me as dearly as before. Deep water decompression is an
emerging science. The benefits gained can be dramatic on the overall
decompression by stopping deep for short periods, typically less than 30
seconds. Too many stops though below 200m though would add heavily to the
overall decompression burden. I chose a relatively slow ascent rate from the
bottom at around 18m per minute for my planned dive to 320m, the first stop was
around 250m, with the next 4 within 18-20 metres of each other. I planned and
planned this dive, fine tuning the gas mixtures so that the Nitrogen values
would be dropping on the ascent after one initial spike early on in the ascent.
Some bad gas choices on the ascent would impact heavily on the decompression,
combined with too much and then too little decompression stops would have
affects similar to my previous dive. The maximum depth gases for this dive
would be largely helium with 20 per cent nitrogen and 5 per cent oxygen (ish).
The relative ratios of the breathing gases can have a dramatic affect within
the body as gases of different solubility and density jockey for up-take and/or
eliminination hierarchies.
I had built my dive plan for a deeper dive before deciding whether I was dive
fit. During the subsequent months I returned to dive fitness (on my own
estimation) and at 10 months post accident felt confidence and fitness were at
levels necessary to attempt a deep dive.
Once the date of the dive was agreed, support divers would need arranging and
briefing and the dive tanks filling. The tanks alone for myself and fourteen
support divers would take 3 full days to fill, and use almost 60 cubic metres
of helium. The tanks were filled just two days before the dive, and this in
hindsight was too close as the process was stressful as was the loading of the
dive boat during a squall that had recently blown in. I had insufficient sleep
that night and would have made an excuse to postpone the dive had the weather
not been perfect by providing gail force winds that day.
The team met early that morning, my feelings were not of confidence at all
and, I felt relief that the weather was simply undivable. Normally I feel quite
optimistic pre dive, but the sheer relief I felt of not going that morning was
incredible. To postpone the dive was an expensive exercise for me, I could
afford to fund one more attempt and then would shelve the project until I had
saved enough to repeat the process. I had wanted to dive during a period of
small tidal movement and the next window of opportunity was 2 weeks away and
exactly 1 week before Christmas day. I did think of rescheduling into the new
year as I did not relish the thought of Christmas Dinner in the recompression
chamber and also the unusual nagging doubts I kept having were taking there
toll.
During the next few days I felt like the storm clouds were passing in my mind,
I started to feel as good as I would need to soon. The following week passed
easily and I managed several practice dives in less than ideal conditions. The
day before the dive I went to bed early mindful of the current windy
conditions. I woke up to blue skies and calm seas and I felt as carefree as a
6metre support diver! The journey to the divesite was 4 hours of smooth seas
and I felt absolute confidence, this helped to ease all the support divers
anxieties and put the whole boat into business mode.
