As if underscoring the sheer range of its training programmes, Dive RAID International has followed up the introduction of its Static and Dynamic Apnea courses, both freediving disciplines undertaken at no depth at all, with its deepest technical scuba option – Hypoxic Trimix Open Circuit to 100m.
The course also provides the alternative route to the 80-100m range covered by RAID's Hypoxic Trimix rebreather course since early 2023.
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The new specialist course departs from most technical training by covering diving on gas mixtures containing extremely low levels of oxygen, requiring, as RAID puts it, “students at the top of their game”.
The partial pressure of oxygen in a standard gas mix at extreme depths is beyond what would normally be considered safe, raising the likelihood of oxygen toxicity, so the training concentrates on getting divers to understand how to use these gas mixtures safely, calculate decompression obligations and handle any emergencies that might arise.
Depth options
There are two certification options: Limited Hypoxic Trimix Open Circuit Diver qualifies divers for depths to 80m, while Hypoxic Trimix Open Circuit Diver enables descents to the full 100m. Both courses build on theoretical knowledge and skills learned in previous courses and introduce new techniques specific to deep diving using multiple decompression strategies and gases.

Candidates should already be comfortable with planning deep open-circuit dives, managing complex equipment packages and teamwork, says RAID. Much of the course focuses on contingency planning, multiple gas switches, pin-point buoyancy control while exchanging stage cylinders, DSMB deployment from depth and support planning.
Correct equipment set-up, pre-dive checks, gas analysis and labelling, and effective communication and problem-solving techniques are all said to be emphasised with a view to instilling confidence and competence.
“Deep trimix diving also brings into play many other psychological and physiological challenges that this programme will prepare you to meet and manage,” says RAID. Start by contacting your local dive-centre.
Also on Divernet: Face-down: the latest RAID freediving course, Dynamic Apnea: New CMAS world record + RAID course, ‘Be the best buddy ever!’ says RAID, RAID adds 100m CCR course, BSAC boosts app