Technical Diving 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 a strong believer in following a team diving concept and recognition that your equipment is not only yours but your teams, that it mind a unified approach is key to survival in extreme conditions. 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 your hard earned cash in something that does not function well for you and your diving.

If you 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. Double 12 ltr tanks will suffice for most extended range dives with additional stage tanks of bottom mix added to extend depth and time.

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.


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 that has become an industry standard 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 60cm length hose place under the divers chin, 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 inline other rather than side by side. This regulator does not have a gauge only a low-pressure inflator for your wing.

The secondary regulator is presented with a 60cm length hose looped behind the divers neck and is 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 for most applications., If you are diving with a wet suit a single bladder will still work fine so long as correct weighting and equipment is selected to avoid over wighting and or use of a lift bag could be used in the event of primary wing 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, 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. 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 should be fixed using 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 Liquavision X1, shearwater, Suunto D9 and Nitek range made by Diverite.

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 is required and can be 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. 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 spool 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 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 wet notes 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