By Don Shirley

Image by Dr Michael Hindley

Becoming a technical diver is less daunting than you might think. It will take a lot of training and hard work, but progressing your diving starts with making that first move.

I am often asked how a diver can get into technical diving. My usual response is that it is something you grow into as your diving progresses. Any diver can become a technical diver and I believe that being trained in technical diving makes you an informed and thoughtful diver, and therefore also a safer diver. As is the case with any level of diving, you can progress as much as you want and have a great time diving at your chosen level. Your progression into technical diving will start by adjusting your techniques and taking control of your diving – like dive planning and using the correct gases for a dive, which will ultimately allow you to dive longer with no or safe decompression. Then, you will learn how to control your decompression with higher levels of oxygen (less inert gas) and in so doing, you will start using larger and/or more cylinders, or even a rebreather. Voilà! You are a gear-festooned technical diver.

It is all about having fun and doing what you want to do while using technology to your advantage. You can never escape the physics and physiology of diving, but you can use exotic gases to control your narcosis levels and correct gas ratios to control your decompression, which will ultimately help you to dive deeper and also to wean off the inert gases.


There are many routes that take you to the higher levels of diving. The number of dives required (you may be surprised by how few dives you need before entering the lower-level courses) and the names of the courses do differ between the agencies, but they will all get you to the top.

Open-circuit and rebreather divers can train side-by-side for most of the climb, just as they can train side-by-side at any recreational level. Think of the pyramid as a three-dimensional shape: when you look at it from different angles, the route may look slightly different, but the end result will remain the same.

Looking at the technical diving pyramid from the simplest angle, progression can be achieved in tandem with your recreational levels (advanced diver, rescue and so on). You will start with nitrox and progress to deep diving where you will learn about redundancy and dive planning. After completing 30 dives, you can start with advanced nitrox diving (what I like to call the border between technical and recreational diving) where you will start diving with a stage cylinder (for decompression) and have redundant systems on your back. This can be done with a single back-mounted cylinder, with double cylinders or with a rebreather.

The next step (technical/normoxic) is when you have reached the 100 dive mark. This is where you can enter the true technical diving world and where you can progress toward no limits diving. As the gas volumes inevitably increase, you will need double cylinders or a rebreather to conduct these dives. Depending on the gases you use, you will be able to dive up to 51-60m in depth. You will also be able to control your bottom and decompression times. The only limitations, or challenges, include your ability to stay warm enough underwater, how far a boat can track you or how far you can swim through a cave (if you are cave diving qualified, of course).

The true depths start calling after reaching the 200 dive mark. After having gained experience in decompression dives below 40m, you will enter the trimix level, which is true no limits diving (keeping in mind that the same limitations apply as with reaching the 100 dive mark). After this, the final level of advancement is the expedition trimix level, which has an entry requirement of 300 dives (of which 100 dives must have been reached at the full trimix level).


Learning how to use a rebreather is not mandatory for reaching the higher levels of technical diving, yet if you consider that you can complete all these courses with a rebreather, you can start climbing the pyramid with a rebreather right from the start, which would inevitably change the pyramid journey. A rebreather is a machine, and after having mastered the machine, it offers you advantages in gas management. Also, with rising helium prices, some divers prefer using rebreathers to using open-circuit systems as rebreather gas is only a fraction of the price of open-circuit gas.


Cave diving requires the highest level of skill sets amongst technical divers, which means that cave divers generally move up the technical diving pyramid quicker and easier, and when they reach the top, they are considered to be truly accomplished divers. Cave diving training can commence at any time during your diving journey. To enlist for the entry level of a cave diving course, which is cavern diving with a single cylinder, you only need to have conducted 10 dives. After 25 dives, you can penetrate deeper into caves, and after having conducted 100 dives, you are allowed to carry out full cave penetrations. After completing your cave diving training, you can carry out all technical diving training levels either while in a cave or in the open water.

So, when you start training to become a technical diver, the journey can be long, especially when looking up from the bottom of the pyramid. But, as always, the journey starts with the first step, and that is always a short one.