Asian Diver and Scuba Diver No. 1/2015 Volume 136 | Page 3
Paul Nicklen/National Geographic Society/Corbis
faster than nitrogen, and
NOAA
and
, i.e., they can be
depending on the planned dive depth, duration, etc.”
32% 36% O2
Strikey says: “The mixes, however, tend to be richer than the ‘standard’
40%-plus
oxygen, is used as a tool to
accelerate in-water decompression stops.
more than
21%
faster than nitrogen.
Nitrox, a mixture of oxygen and air that comprises
Strikey says: “Looks good to me!”
helium saturates and desaturates some
3.7 times
2.7 times
Hydrogen saturates and desaturates approximately
The Gassy Game
Nobody ever said air was the best gas
to breathe underwater, so here are
some figures to crunch on the quest for
deep diving perfection.
Asian Diver’s tek consultant, David
Strike, aka Strikey, recalculates…
DIVING BY NUMBERS
helium, the inert gas of choice.
25%
to
50%
33%, say 40%
to
. Cost, as well as narcosis, enters the equation,
although, in a perfect diving world, cost should never have
a role.”
the depth, so it may be higher than
Strikey says: “The ratio of helium in the mix will depend on
30%
Common trimix calls for
Strikey says: “The French commercial diving company, Comex,
experimented with hydrox mixtures but found no real advantage.
Later experiments, in which they added helium to the mix, were
more successful, however. Hydrogen conducts heat away from
the body more rapidly than, say, helium. Also, because it is highly
flammable and explodes, great care has to be taken when mixing,
handling and storing the gas, considerations that impose an
additional cost-burden on its use.”
in commercial diving.
130 metres
Hydreliox is a mixture of oxygen,
helium and hydrogen, targeted at dives below
Strikey says: “Tolerance levels to
toxicity
vary enormously within the same individual
from day to day.”
O2
may create a high risk of oxygen toxicity,
which could result in death.
21%
55 metres
Breathing normal air with
oxygen at depths greater than