NAUI Trimix Diver

What will you learn?

The NAUI Trimix Course builds on your foundation skills and on the dive experiences of your previous technical courses, but with the addition of learning how to dive with more than one deco cylinder on dives requiring more substantial decompression time.

Our NAUI Trimix Diver Course gradually steps you deeper and deeper as deco stops get deeper and longer and your dive sites get bigger and deeper.

You’ll learn how to manage Normoxic trimix 16-18% oxygen depending on agency (NAUI vs. TDI) to a maximum training depth of 240′ (NAUI) or 200′ (TDI).


Rescue Diver
Technical Decompression Diver
100+ logged dives


This course is available privately for individuals or groups available locally or wherever you are located.

Course is often conducted in 5 days intensively or over 2 long weekends.

Training Agency:


Additional Details:

Our Trimix Diver Course is for technical divers wishing to dive to a deeper depth taking advantage of the benefits of a true Trimix dilluting the partial pressure of Nitrogen (reducing Narcosis) and in deeper diving dilluting the PPO2 to avoid CNS O2 Toxicity.

This course covers topics such as Helium, Oxygen, Nitrogen for breathing gasses. Argon, CO2, Carbon Monoxide, advanced physiogy, physics and chemistry of diving (kinetic energy, specific heat capacity, tissue solubility and more), dive planning, table model comparisons, Isobaric Counterdiffusion and variations of trimixes are just a few of the many topics to be discussed. To enroll in either Trimix course, you must be certified as a diver with Advanced Nitrox, Decompression Techniques, Helitrox, Heliair.

The Trimix Diver Course consists of two levels. These courses will give you the skills and knowledge needed to minimize the risks of utilizing helium-based Trimix breathing gas mixes for dives to a maximum depth of 240′ requiring staged decompression and utilizing EANx mixtures and/or oxygen during decompression at Trimix 1 and up to 330′ for Trimix 2.

These Team driven programs offer some of the most challenging skills found in technical diving and test the diver more than any previous course to date in the students technical diving path. Upon Successful Completion of the course you will be able to plan and execute technical dives that require staged decompression and utilize helium-based trimix breathing gas mixtures and EANx and/or oxygen for staged decompression to depths above 240′.

When the Diver gets to the Trimix level they are the most experienced technical divers. Extensive experience in double tanks is needed prior to enrolling in this course. We expect a minimum of 100 dives, 25 of which should have required mandatory decompression. Trimix Divers wishing to upgrade their skill sets, depth rating, knowledge and procedures will move into our Trimix Level II course.

Our Trimix Level II Course will teach you how to safely extend your diving depths down to 330′. The Trimix Level II Course will teach you more advanced methods and procedures. Students will work with up to 3 stage/deco bottles, optimizing your mixes in deeper dives extending your bottom time, offgassing more effectively, the course also dissects expedition trimix diving and what expedition diving is all about. Extensive experience in double tanks is needed prior to enrolling in this course.

For Trimix Level II we would like a minimum of 125 dives. 50 dives should be decompression or mixed gas dives.This is one of the most serious diving courses, as such, candidates should think long and hard about whether or not they should be participating in this program. This basically means, Practice, Practice, Practice before you enroll in this course or you will be re-taking your Advanced Nitrox/Decompression Procedures course over again. This really happens which is why we’re making this point.

Divers crossing into one of our Trimix Courses will be required to do a skills equivalency of all NAUI Intro to Tech Skills in open water prior to acceptance in our courses due to the large number of students we’ve had to retrain.  Upon completion of the intro skills, a decompression checkout will be required as well to check all of the required skills off the list before acceptance.

This course is to provide the diver with the experience and knowledge needed to minimize the risk of diving beyond 73m (240 ft.) while utilizing helium-based trimix breathing mixtures, hypoxic trimix breathing mixtures, helium based and EANx-based travel gases as well as EANx and oxygen during decompression.

Upon successful completion of this course, graduates are considered competent to plan and execute a team- based technical dive that requires travel gasses, staged decompression, helium based trimix breathing mixtures, and EANx and/or oxygen for decompression without direct supervision for dives that exceed 73m (240 ft.) provided the diving activities and the areas dived approximate those of training.

Cost is only $999 +GST for Trimix Diver Level 1 or $1695+GST as a combination course (Trimix 1&2).

What gear will you need?

Full Technical Gear Package and a minimum of 2 decompression cylinders properly rigged with MOD Markings and drysuit inflation system.

Where do I go from here?

Here are some popular examples of courses commonly taken by graduates of this course:

  • CCR Explorer
  • Cave 1
  • Cave 2
  • Technical Wreck Penetration
  • Sidemount Diver