Nov 2014

Introduction to Technical Diving

By Mike Waddington

If you have been diving for a while you may feel like you have exhausted most of the potential routes. You may have finished your Rescue diver, and completed some specialties such as Nitrox, Deep or Wreck and still feel that you want more out of diving, like you need a new challenge. Well if you feel that way then you should have a look at taking up some technical diving, or more commonly known as ‘tec diving’.

What is Technical Diving?

The term technical diving means diving beyond the realms of recreational diving, using extensive equipment to go deeper or stay down for longer. Technical diving is not simply breaking the limits set out for recreational diving. Technical Diving done correctly should involve planning your gas needs, planning out any required decompression and having backups to everything that you may need to keep you alive.

Technical Diving Equipment

If you sign up for a technical diving course you will be using some new equipment that you have probably never used before. First of all now you need at least two tanks, maybe more depending on what you will be doing. The most common set up for technical diving is called a twinset. This is two tanks of equal size that have been connected via a ‘Manifold’. The reason behind this is because if there is ever an emergency such as a severe gas hemorrhage, you need to be able to isolate the problem, and still have gas to breathe. This is why there will be three valves on your twinset. One to open and close each cylinder valve, and one to close the manifold. If you are planning on decompression diving then you will also be using decompression tanks, also known as a ‘deco package’. This is an extra tank, which should be worn on your left side via sliding gate clips. The tank will have markings on it such as maximum operating depth (MOD), your name, and the percentage of what gas is in there. Attached will be a regulator first stage, with a second stage and an SPG so you can monitor your air supply.

The regulators will look slightly different to what you are used to as well. As you have 2 cylinders you also need 2 regulator first stages. On your left first stage you will have a second stage on a short hose and an SPG which should also have a clip so it does not dangle, and on your right you will have a second stage which is attached via a 2m long hose, and low pressure inflator hose (LPI) to connect to your ‘wing’.

You will not be wearing a BCD for technical diving, but instead you will be wearing a wing and harness. The wing acts as your buoyancy device, and is held in place by the harness which consists of either a stainless steel or aluminum back-plate, which has webbing run through in various places so you can wear it. This is then bolted to your twinset via wingnuts, so when you are wearing your ‘technical rig’ you are literally bolted to your tanks.

Technical Diver Training

The training itself if very different from your previous dive training. When you completed your previous courses you would have completed skills on each dive, and afterwards you would be taken on a tour of the dive site. During a technical training dive you will have skills thrown at you constantly, and often many at a time. Because if an emergency really happened underwater you cannot simply go up to the surface as doing so could result in a serious injury, you must be able to deal with any issue underwater. Almost all of the skills you will deal with are emergency procedures such as gas shut down, out of air, free flowing regulators and loss of equipment. By practicing them many times, and while trying to complete other important procedures you will gain automatic responses so if there are problems on a real dive you will react instinctively instead of stopping and thinking about what to do.

Apart from technical diving taking you to greater depths, it also allows you to go further into shipwrecks, deeper into caves or under ice sheets. Taking part in overhead diving has many of its own dangers. A major one is the possibility of entanglement. It is vital in technical diving that we are completely streamlined, as anything dangling is sure to get wrapped around a guide line, or trapped in a crack or small hole. You will practice proper streamlining right from the beginning, even though you won’t be going overhead for a while. This will include not just the streamlining of your equipment, but also of yourself. The proper position for technical diving is called “Being in trim”. Divers in ‘trim’ will be completely horizontal in the water, with their knees bent upwards and their arms held out in front of them. The best way to describe ‘trim’ is like the skydiving position. When combined with an efficient frog kick, and streamlined gear the diver will greatly reduce the risk of stirring up silt on the bottom, or getting anything entangled.

Technical diving is a rewarding experience that will take your diving further than it has ever gone before. If you have no interest in going deep or cave diving the training will still make you into a better diver, which will really improve your ability to deal with problems and handle emergencies. If you are interested in learning more about technical diving then you should look at programs such as PADI DSAT Tec 40, or TDI intro to Tec.

‘Introduction to Technical Diving’ was written by Mike

Photo Credit: Professional Scuba Instruction

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Mike Waddington

I first discovered diving in 2008 after going snorkeling on the Great Barrier Reef in Australia. After trying diving at a flooded quarry in England I decided to head out to warmer more interesting waters in Thailand where I ended on the Island of Koh Tao completing my Open Water course. Instantly addicted with money to spend and plenty of time on my hands I decided to continue until I became a Divemaster so I could live what seemed as the perfect life.

After that I headed to the Caribbean to an island called Utila to complete my instructor course, I spent several months out there completing the MSDT internship, teaching students and leading dives. This is also where I discovered my interest in the technical side of diving, taking part in equipment repair courses and learning about blending gasses and running compressors.

With all my new qualifications it was time to head back to where it had all started, Back to Koh Tao where I intended on living the dream. Once I arrived I quickly found a job and started teaching straight away. During my time on Koh Tao I took part in all many technical diving courses, learning how to dive with re-breathers, in caves and even going down to 90m/300ft!


PADI Master Scuba Diver Trainer
PADI/DSAT Tech Deep Instructor
PADI/DSAT Gas Trimix Gas Blender
PADI/DSAT Trimix Diver
TDI Intro to Cave Diver
TDI Advanced Wreck Diver
TDI Inspiration rebreather Decompression Procedures
PADI Professional Videographer
BSAC Compressor Operator
TDI Equipment Service Technician

Dream Dive Locations:

Silfra, Iceland
Cenotes, Mexico
Chuuk Lagoon, Micronesia
Ice Diving in Russia