Ratio Deco Q&A
Hello!
I am a PADI Msdt and
technical diver. Most of
my technical training is
with TDI, including
rebreather and OC
trimix.
I have watched a video
in which Andrew was
praising ratio decom-
pression planning on
the go. While I can see
some relevancy, I am
still a bit puzzled.
I haven’t found much
material on this and
was wondering if you
could share some
references or material
on this?
The background of Ratio Deco starts with a core
understanding that it a decompression strategy – not
a scientific theory – that is based on five or more
different “decompression theories.” These include
gradient models, Haldan and other Neo Haldanian
models such as Bulhman and Workman, as well as
bubble mechanics models such as VPM/RGBM.
Then we use deep stop theories from Brian Hills,
Pyle, WKPP and ultimately our UTD 5-year Ratio
Deco study in Italy. Lastly we add O2 windows as
described by Mornsen, Behnke, Bennet and Elliot.
These have all been combined into practice over
the past 20 years by thousands of recreational and
technical divers. More importantly, Ratio Deco has
been used in very large and deep projects by var-
ies groups – WKKP, SCRET, EJKPP, SCKPP, and
many others that have done over 600’/180m dives
for 6 hour bottom times. Those dives on a Bulh-
man or VPM model would of been prohibitive as
they would require up to 36 hours of decompression
time, yet Ratio Deco proved we could exit in less
than eight hours, “Max Deco.”
Of course I realize that not every one wants to
do a 600’ dive for six hours bottom time, but the
advantage to the average technical diver is that
Ratio Deco is NOT one-size-fits-all theory such as
a computer. Because we are a living organism, not
everyone is the same – or even close to the same.
Your decompression approach needs to be a living
strategy that you develop over your knowledge,
experience and time, then you slowly apply to your
diving.
This deco strategy does not numb your understand-
ing such as relying on a computer, blinding trusting
that what it says works, but starts by you complete-
ly immersing yourself in understand all decompres-
sion theories and then slowly applying the best of
each towards your diving. Then over time tweaking
it out to evolve into what works for you and your
team. There is no CYA like you find in ALL com-
puters, as RD is customized by you for you.
TM
Andrew Georgitsis