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Technical Equipment
Over the years we have evolved a basic technical
diving rig that has been adopted by many open
ocean, wreck and cave divers. I have decided to
highlight some of the key equipment requirements
for Technical diving, with some additional considerations.
I am not a believer in cults and recognize that
many people have personal preferences when it
comes to equipment selections. The information
below has been derived from my experience over
1000’s of dives and is aimed at the newcomers
to our sport. Technical Diving equipment is expensive
and continually replacing worn equipment is essential
if your life depends on it. Think hard and long
before you invest you’re hard earned cash in something
that does not function well for you and your diving.
If your require advice regarding technical equipment
purchases prior to training please do not hesitate
to ask as we are able to supply equipment from
most major brands and only recommend equipment
we would use for our Technical dives.
Navigation
Tanks, Bands & Manifolds
Technical Diving calls for larger capacity cylinders.
Generally two are mounted together with some type
of band system and mount to a divers back-plate
with a bolt kit. The valves incorporate a manifold
system, designed to allow the diver access to
the gas in the event of a failure to one side.
If diving is taking place in a dry suit I would
generally opt for a set of steel tanks as they
are quite a bit heavier than aluminum tanks reducing
the required amount of Kg added to a weight belt.
I am also keen on double seven 300 Bar tanks as
they are very compact and have a gas supply of
4200 Litres which would suffice for most extended
range dives. Larger capacity tanks up-to double
20 litre are used for deep Trimix dives.
Ensuring a good fitting set of bands is essential
to the functionality of your twin-set. The manifold
could become stressed if the bands are not holding
the tanks together correctly, this could result
in dual valve failure causing a catastrophic gas
loss during a dive. Good quality stainless bands
can be brought from most technical diving suppliers.
I particularly like the Custom Divers and OMS
stainless steel bands.
Regulators
With the market a wash with many different regulator
designs what things should you consider when selecting
regulators for Technical Dives?
Servicing availability and cost. You will probably
need them serviced more often to keep them in
tiptop shape.
Confidence in you regulator. When you first started
diving you were taught to trust your equipment
and to a certain extent I believe this still to
be true. If you like it stick with it, there is
no need to ditch all your existing kit.
One thing I like is a primary regulator on a
long hose approximately 2m in length. This regulator
loops under your right arm, around the back of
your neck and into your mouth. This system allows
a diver to pass of their regulator, switch to
a back up on a standard length hose, giving both
divers space to swim. Its the best option should
you need to pass off gas to a following diver
inside an overhead environment when exiting requires
divers to swim behind each other rather than side
by side. This regulator does not have a gauge
only a low-pressure inflator if a redundant BCD
is being used.
The secondary regulator is presented with a standard
length hose looped behind the divers neck and
is either clipped to a D-ring on the divers harness
or bungeed under the divers chin. This regulator
should have a submersible pressure gauge, as your
primary does not.
Wing / Buoyancy Control
There are many manufactures producing wings in
all different designs, Bungeed, Un-bungeed, dual
and single bladders in many different colors shapes
and sizes. So what things need to be considered?
Does the wing provide enough lift /buoyancy in
the water when wearing full equipment this is
termed as the wings lift capacity and expressed
in Pounds. Somewhere between 45-60lbs should generally
do the job for most applications?
Single bladder wings are suitable only if the
diver is diving with a dry-suit, which can be
used as back up buoyancy if your wing should fail
in some way. If you are diving with a wet suit
a double bladder totally independent wing should
be used in case of a failure.
Back plates and harness systems
Back plates are available generally in either
aluminum or stainless steel and tend to look very
similar in design. All will have holes punched
into the centre for attaching your plate to the
bands on your double tanks. Holes are also positioned
for mounting canister lights; lift bags / surface
markers and dry suit inflation cylinders. If you
choose a plate from one of the mainstream technical
manufactures, OMS, Diverite, Halcyon, you will
not go far wrong.
Regarding harness systems there are three different
styles to choose from. Comfort harness with lots
of foam padding around the shoulders and back
area fitted with a selection of D-ring for stage
tanks. Straight through webbing with no quick
release buckles other than the waistband, the
idea being no failures from weak points on the
harness, the downside is donning and doffing the
harness while wearing a thick suit. Then somewhere
in the middle you could opt for a webbed harness
with adjustable quick release buckles keeping
your harness simple yet still easy to put on and of.
Dive lights
Technical Diving in low light conditions require
the diver to carry dive lights and back up lights.
Standard handheld dive lamps used by recreational
divers are usually not suited to technical diving
either depth rating is insufficient or burn time
not enough.
When selecting a good primary light most technical
divers choose the canister type rechargeable battery
pack and separate light head. The larger battery
pack is then either mounted to the divers back
plate or waste band / hip of the diver. The head
can either be hand held, mounted to a helmet or
position to a Goodman handle to allow the divers
hands to work freely.
Modern LED bulb technology seems to be the way
forward with these bulbs working for thousands
of hrs before they need replacing. HID technology
is still a popular choice giving great brightness
and good burn times. The drawback is replacing
the bulbs can prove very costly.
If a technical dive requires the use of a primary
light then the diver must carry back up lights
at least two and in overhead environments three.
They generally do not need to be as powerful and
long lasting as your primary as you should be
turning a dive when forced to use your back up.
A small scout light attached to your harness would
normally suffice. Maybe you could even use your
old recreational dive light if its not to big.
Computers, gauges and instruments
Computer technology for technical diving is constantly
changing and staying up-to date is a costly one.
The Vr3 from Delta P technologies manufactured
in the UK provides the modern technical diver
with an upgradeable full multi gas, Trimix and
rebreather compatible dive computer. It can be
PC interfaced for post dive viewing and is my
personal choice for all my dives. Other options
available on the market include the HS Explorer,
Suunto D9 and Nitek range made by Diverite. None
of which are upgradeable.
On all technical dives, you are required to carry
a back up depth/timing device and usually any
dive computer that has a gauge only function will
do. Many divers simply use a digital gauge similar
to those made by Uwatec.
A Compass may be required but is usually kept
stored away in a pocket the important consideration
is that the compass is liquid filled to avoid
it imploding at depth.
Exposure protection
Hypothermia and hyperthermia are both very real
problems that face the Technical Diver. The fact
that most technical dives require longer in water
exposures compared with a regular recreational
dives the need for a dry suit arises. On some
short exposures in the tropics you may get away
with a 5-7mm wet suit with hood and gloves but
I find that the overall enjoyment is increased
when I feel totally comfortable and warm in a
dry suit. Divers should select a custom made suit
to insure a good fit , an incorrect fitting suit
will play havoc with your in water comfort, trim
and buoyancy. Another mistake divers make is opting
for the thickest under suit they can find believing
it will keep them warm instead of one of the more
effectively designed lighter weight two and three
piece Thinsulates on the market. The thicker under
suits generally hold pockets of air that move
around as well as requiring much more weight for
the diver to submerge.
Some useful addition to your suit are cargo pockets
for storing buoys, slates spare masks and another
useful accessories. Adding a balanced pee valve
ensures the diver is able to urinate during the
dive, a must for planned long exposures. The female
dive would generally go for an adult dipper for
comfort. Adding a well fitting hood and gloves
combined with a well made dry suit will ensure
the diver can stay comfortable for long duration
even in freezing condition.
Reels / Spools
The technical diver includes several different
reels in his/her gear bag. I do not believe there
is a good single multi purpose reel on the market.
A reel used for deploying a surface marker would
generally not be designed for a long wreck or
cave penetration. A primary reel is recommended
for laying a primary guideline inside a wreck
or cave system and normally has between 90 and
150m of good quality line. If used correctly some
can be used easily as an up line with a buoy/
SMB. Jump reels and spools are generally smaller
in size but similar in design to a primary reel
and typically hold 40-55m of line and a used for
tying off from a primary line source. Some diver
use a spool as a back up to their SMB reel which
is totally acceptable so long as the divers is
capable of using it with ease.
Some consideration when choosing a suitable technical reel include
How easy is it for the line to become tangled
around the spool and jamming
A suitable reel should have more line on than
the planned maximum depth
Ratchets and springs have a tendency to break
easily try to avoid these weak areas
Buoys / Lift Bags
Surface marker boys come in all shapes, sizes
and colors yellow, red, yellow and red. The idea
being that the Technical divers selects a buoy
with sufficient lift for the job. The longer self
sealing SMB are great for free drifting decompression
allowing the boat to follow the diver for the
decompression period in areas with current. Lifting
objects from the bottom generally require a higher
lift capacity than this type of SMB. Larger volume
lift bags generally do not self-seal so the bag
does not burst on accent.
Accessories
As with every specialist activity there are many
accessories available from custom made slates
to clips and bits. It’s a bit unrealistic to include
all the available items on the market bit I have
listed below some of the items you may find useful.
- A selection of slates & wet-notes
- Spare masks
- Cutting tools – Knife, Z-Knife, scissors
- Jon-Line
- Emergency Signaling devises
- A good selection of clips
- Stage Rigging device
- Good quality fin straps
- Tools kit
- Selection of spares
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