What Is Tech Diving?

Tech diving (short for “technical”) is both a new branch of diving and a very old tradition. In essence Tech diving is a crossover of longstanding commercial diving techniques and modern recreational diving goals. A Tech diver will use very sophisticated dive methods and equipment that have been developed and refined in military and commercial diving to achieve personal, fun goals. It is a hobby, a passion and an adventure. Tech diving isn’t for everyone, many of the rewards that Tech diving can bestow are not given up lightly; often Tech divers go through discomfort and must train for a long time in order to go where they wish. It is not all clear water, designer wetsuits and beaches; it is often hard work, risk taking and tedious waiting that brings the results the Tech divers seek, not to mention the exorbitant cost of the training and specialist gear!

Tech Divers May Look Funny (And Smell Funny) But Their Devotion To The Sport Is Serious

So If It’s So Hard, Why Do People Tech Dive?

Tec diving is a peculiar sport because, to many other divers, it seems an awful lot like hard work when a normal diver can have a great dive at ten metres and spend comparatively little money. The reason the Tec guys do it however, is simple; Tec divers like to do things to extremes and thus they need extreme methods and equipment to accomplish what they desire. So, what does a Tec diver desire?

To Go Deeper, For Longer

The primary reason that Tech diving exists is because standard recreational diving has many, very difficult limits imposed upon it such as air consumption, water temperature and nitrogen buildup. These factors all impose boundaries on what can be done during a dive, they especially restrict the maximum depth a diver can reach and for how long he can stay there. If a diver wishes to stay longer or go deeper than the standard recreational tables recommend then he must use other techniques and equipment, thus he becomes a Tech diver. For instance, if a standard diver went to thirty meters he’d find that his computer gave him a very short bottom time because of nitrogen buildup, he’d also notice that his air was being used up very fast and he’d probably be getting fairly chilly too. The Tech diver aims to solve these problems by breathing modified gasses to extend his bottom time, he would carry more than one tank of breathing gas to extend his air supply and he’d likely wear a high quality drysuit to take care of the chills. There are many techniques and pieces of gear that a Tech diver has in his armory, but almost all of them are used purely to let him dive deeper, for longer.

Tec Diving Is Not Just About Going Deep, It Is Also Used To Stay Shallow For A Long Time.

Divers Love Gear

I’ve said it many times before and I’ll say it again; diving’s popularity as a sport is massively aided by the fact that people like to buy things, use tools and customize stuff. The fact that the dive industry is so glamorous proves this – people aren’t just buying a lump of technology to let them go diving, they are buying the latest airmax master turbo super gasblaster regulator airflow system! Diving is a “cool” industry and manages to maintain it’s “cred” by selling funky gadgets. I’d argue that a large proportion of Tech divers got into extreme diving purely for the gear that comes with it. The case and point being the re-breather which is the ultimate in James Bond type gadgets. The re-breather is an excellent tool that can achieve much, but its beauty lies in its complicated nature, the fact that a true disciple of technology will be blissfully lost in manuals and tool for hours getting it set up and ready to use is a large part of its appeal. Tech divers are gadget freaks, the clue is in their name!

Tec Divers Are Suckers For New Gear…

The Adventure!

So why on Earth would anyone want to go through all the training, spend the crazy money, endure the hardships and take the risks purely so they can go deep? The answer is often because Tech divers are an adventurous bunch who want to go places that others cannot or dare not. They want to dive on wrecks that have never been seen by the human eye since the day it sunk, they want to find deep fish that have never been named and they want to explore cave systems that are barely even known of, let alone mapped. The equipment and training that Tech divers use allows them to truly go where no man has gone before, and that is a very potent lure for some.

To Challenge Themselves

Ok, so you can accept that there are people out there who do expensive and difficult things to go down for longer in order to see stuff that nobody else has seen, but ultimately what’s the point? The Tech diver has an answer for this too; the challenge! Why else would somebody do horrible and dangerous things? To challenge themselves with a serious obstacle (in this case: the human body vs the whole ocean), learn and train how to overcome it and then do so triumphantly. Nowadays there are few frontiers left; Everest is crowded with families on vacation, you can barely see the sun for all the skydivers, the poles have gift shops on them and it is verging on dangerous to sail on the oceans now from all the one man craft zipping about. The only really hardcore frontier left on Earth is the Deep itself. Instead of climbing mountains, Tech divers drop into bottomless pits and do their damnedest to get back out again.

The Gear And Techniques:

Nitrox and Trimix

Tech divers need to beat the bottom time calculator in order to go where they want, which means using specialist breathing gases. Nitrox is the first port of call when looking into Tech diving because it allows you to extend you dive time beyond standard tables. Nitrox is basically a breathing gas that has had the nitrogen reduced and the oxygen increased. This means that the diver’s body absorbs less nitrogen during the dive and allows their computer to be more lenient. This gas mixture can be varied for the depth the diver plans on going. He may even take more than one mixture to allow him to swap during the dive to make his computer read more favorably still.

There is a limit to what Nitrox can do though because highly concentrated oxygen has adverse effects on the human body, which means there is a balancing act between how much oxygen is put into the mix versus nitrogen. The way this issue is alleviated is by adding a third gas, usually helium, which is a noble gas and therefore has very little reactive qualities. By adding helium to the gas blend, a Tech diver can make a concentration that will (at the appropriate depth) allow him to breath very little nitrogen but not get hurt by the oxygen. This gas switching is the primary reason that Tech divers require so much training, so many tanks and so much money. This really is technical!

It Is Not Uncommon For Tec Divers To Carry Up To Eight Tanks Containing Different Breathing Gas Mixes.


Even with all the gasses and mixes available to a Tech diver, his computer will eventually run out of no-decompression time, which means that before he can come to the surface he will be required to do at least one decompression stop. This allows the nitrogen in his body to escape in controlled bursts, thus preventing DCS. Depending on the depth, time and type of gas he is breathing, a Tech diver might be required to decompress for a few hours! Which means being bored and cold for a long time!


Tech divers go very deep, for very long and often they dive solo. This means that they require all their gear to function perfectly at all times. Of course, humans aren’t perfect which means that gear will inevitably falter at some point for some poor guy. The way Tech divers deal with this possibility is by carrying a spare of every item of dive gear. He will carry two knives, masks, computers, lights (maybe three) and several regulators. A Tech diver might be required to decompress for hours, which means lots of breathing gas is required, so many Tech divers have their decompression gasses suspended from a line at the appropriate depths. This means they have redundant gas mixes too. Tech divers do take risks, but the techniques they use are designed to reduce them to almost negligible levels.

One way to tell if a diver is a Tech diver or not is by looking at his BCD, if it looks like a jacket then he is probably not a Tech diver, if it looks like a metal plate with a big ballon on it and compression straps then he is. These BCDs are designed to compensate for the massive amount of weight these divers carry in the form of redundant gear and extra tanks.

Final Thoughts

Whenever I hear stories about people who have done amazing things by working hard and learning new skills I am always impressed, but none impress me more than Tech divers. I feel this amazement because a Tech diver is one of the few people in the world who has the chance to see something truly new. They are the last voyagers on Earth and their commitment to exploration and challenge is inspirational… and I also love their gear!

Do you wish to start Tech diving? If you are already Tech diving, what’s your favorite dive story? What mixes and gear setup to you favor? Please share your experiences by using the comment section bellow.

Happy (gas-blended) bubbles!

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