Technical Scuba Diving: What Is Trimix

Deep sea diving is as mesmerizing as a carefully planned trip to the deep underwaters. Even the vocational divers are trained before they are taken for the underwater tour. Like going on a holiday and getting to enjoy scuba diving seems so romantic and enchanting, but you are prepared before the tour operators take you for scuba diving, right!

Some professional divers are experienced, and experts in diving and going much beyond any other prison can go. It takes years of practice, training, and technically advanced equipment build especially for scuba diving.

Apart from other scuba gears, the most important is the breathable gas. It is of course, tough to breathe underwater even with using gas cylinders. The pressure under water increases as you go deeper and those experts divers need something more efficient than just oxygen cylinders to breathe. It’s because they go much more in-depth you have to travel a much longer distance to return to shore, not to forget they say underwater for the considerably more extended time.

The Trimix is the answer for operational and efficient gas for advanced scuba diving. Many of you who are familiar with scuba diving must be aware of this gas. But those new to this adventure may not know much about it. So here is everything you must know about the trimix gas.


The trimix name itself is not much complicated to understand, tri+mix. That is a mixture of three(gas). The trimix is a well-balanced combination of three significant gases, oxygen, helium and nitrogen. This mixture is created to increase the safety of deep sea divers as it is challenging to breathe under pressure in the deep sea also it helps control of side effects in the health of the divers.

Now, coming to the percentage composition of each of these three gas in the mixture, there are many variants in the composition, but the gases always remain the same. Which means a diver can get any different percentage composition of oxygen, helium, and nitrogen ( but no other gas than these three).

Example: a 20/30 trimix indicates 20% oxygen, 30% helium and an unmentioned but indicative 50% nitrogen.

Origin of trimix

Although, the first use of trimix or explicitly speaking helium mix gas was somewhere around the Second World War by the Navy divers of British and America. However, the trimix came to light by cave divers during the 1970’s only.

With the scuba diving and the technical diving industry coming to light and growing fast, use of trimix is becoming widespread. As a matter of fact, any diving beyond 150 ft requires the use of trimix only.

Benefits of using trimix

As per Boyle’s Law, the pressure around a diver increases as he dives deeper. More the pressure, the gas in the body compresses to levels human body can’t hold, Leading to conditions like nitrogen narcosis or even oxygen toxicity. Thus using a safe mix of the three gases help in maintaining the breathable gas pressure under water and ensures the safety of the divers.