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There
are many differences in the way a recreational and technical
diver configure their equipment. One of the most distinctive aspects of
a technical diving setup is the use of a long hose on the primary
regulator. A typical recreational diver will have their main regulator
and then an ‘octopus’ regulator which can be
donated to their buddy in
case of emergency. This octopus reg is often, but not always, on a
slightly longer hose than the main regulator. Technical divers tend to
use a much longer hose, from 1.5m to 2m in length. There are a number
of reasons for this. When diving in an overhead environment such as a
cave or inside a wreck then if one diver were to go out of air (OOA),
it may be difficult to swim out whilst in the side by side position
that a normal length octopus would require. With a long hose, the
divers can be one in front of the other and so can easily swim through
restrictions.
Of course, most recreational divers will
never go anywhere near a cave or carry out any level of wreck
penetration but a long hose is still useful, even in an open water
environment. In an OOA situation you will need to be very close to your
buddy if they have a traditional octopus. Most OOA drills are carried
out in calm conditions with both divers kneeling on the bottom of a
pool or on a convenient bit of sea bed that the instructor knows is
ideal for this drill. Once the OOA diver has taken a few breaths the
instructor signals that the drill is over and the dive continues.
Unfortunately this isn’t very realistic. In a real OOA
situation you
may need to remain neutrally buoyant as there may not be a convenient
patch of sand immediately beneath you. If one of you is OOA then you
will need to ascend to the surface. If you try to ascend while
breathing off your buddy’s short hose, you will need to be
very close
together. Sending up a delayed SMB, controlling the ascent and holding
a safety stop are much more difficult when you are very close together
and ‘in each others faces’. Combined with the
stress of the initial OOA
this can be enough to turn a difficult situation into a full blown
incident.
On a no-stop dive this may cause problems and
will be inconvenient. Controlling the ascent rate and holding a three
minute safety stop will not be easy. It is for these reasons that OOA
situations are often associated with rapid or uncontrolled ascents. An
uncontrolled ascent is bad enough on a no-stop dive. However, if you
are doing a decompression dive and have mandatory decompression then it
is simply not an option.
The use of a long hose enables you
to be slightly further away from your buddy. This gives you the space
to perform all of these tasks with enough room to remain comfortable
and composed. Once you have passed over your regulator and deployed
your long hose you can maintain your normal in-water position and the
ascent is then no more difficult than if your buddy was breathing their
own regulator.
The use of a long hose is closely associated
with technical diving and is often seen in conjunction with a twinset.
However a long hose is not restricted to a twinset and it is possible
to use this configuration even on a recreational single cylinder set
up.
The long hose could go on the octopus but most
technical divers put the long hose on their primary regulator. This is
because in the case of an OOA they would plan to donate the reg in
their mouth. This is not what the majority of divers were taught on
their entry level course so why should this method be adopted? The
first reason for donating the regulator in your mouth is that you know
this regulator is working. The OOA diver will be under stress and
putting a working regulator in their mouth is the quickest way to calm
them down. Another reason is that many people believe that an OOA diver
is more likely to take the regulator from your mouth rather than
hunting around for an octopus.
The last reason is that
technical divers frequently carry multiple cylinders. These cylinders
carry gasses which are only breathable at certain points of the dive.
If you breathe the gas at the wrong depth then Oxygen toxicity could be
a very real risk. We know that the reg in our mouth always contains
breathable gas and so by donating this reg we are ensuring that the OOA
diver is getting a safe source of gas.
Of course if we
donate our reg then that leaves us with no reg. This is not a situation
that we want to be in for very long. If we now need to start hunting
around for our backup, ensuring that we don’t take a deco gas
reg by
mistake, then we are just moving the problem along from the OOA diver
to ourselves. For this reason the technical diver does not store his
backup in his pocket, dangling by his hip or clipped somewhere on his
chest but instead he stores it on a bungee around his neck. This means
that once they have donated their primary it is just a question of
ducking the head and putting the bungied backup into their mouth.
Using
a long hose is sometimes criticised for being non-standard or even
confusing, especially when training new divers. I have always found
that a good buddy check, where you explain your kit configuration, is
very effective at removing any queries. This is especially true for new
divers. After all, as all of the kit is new to them they
don’t know
whether your kit is standard or not. In many cases new divers are the
most open to the long hose configurati on as they are not
preconditioned
to think of the standard configuration as the only option.
The above article was written
by Mark Powel, one of only a few full
time Technical Instructors in the UK.
If you would like to discuss any aspects of Technical training with
Mark, please contact him direct on 07770 864327. |
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