SSI CCR Hypoxic Trimix eLearning

SSI CCR Hypoxic Trimix Diving — eLearning & Certification Credit Only

Push the boundaries of technical diving with the SSI CCR Hypoxic Trimix Diving specialty — the pinnacle of closed-circuit rebreather training. This advanced-level course is designed for highly experienced CCR divers who wish to explore extreme depths using hypoxic trimix gas blends. This product provides your academic training and certification credit only; all practical training dives must be completed separately with an authorised SSI Extended Range Instructor Trainer.

What you’ll learn online

• Advanced theory of closed-circuit rebreather (CCR) function and physiology
• Gas blending and management for hypoxic trimix operations
• Decompression theory, dive planning, and bailout procedures for deep dives
• CCR setup, pre-dive checks, calibration, and maintenance at advanced levels
• Navigation, redundancy configuration, and mission planning
• Problem recognition, emergency procedures, and bailout gas strategies
• Stress management and team protocols under extreme depth conditions
• Environmental awareness and responsible expedition-level diving

Required practical training (booked separately)

To complete your certification, you must undertake in-water CCR training dives with an authorised SSI Extended Range Instructor Trainer. The practical portion of this course includes:

• Progressive CCR dives using hypoxic trimix gas blends
• Simulated equipment failures, emergency bailout ascents, and decompression drills
• Multi-stage dive planning and execution at depths up to 100 metres (330 feet)
• Gas analysis, verification, and rebreather system management in extreme environments
• Team protocols, communication, and situational awareness at technical depths

These practical sessions are not included with this eLearning product and must be booked separately with Dorset Diving or another SSI Extended Range Dive Centre that offers CCR Hypoxic Trimix training.

Important prerequisites

• You must be at least 18 years old and hold certification as an SSI CCR Extended Range Trimix Diver (or equivalent).
• A minimum of 100 logged dives, including at least 25 hours on the specific CCR unit to be used, is required before beginning practical training.
• Valid first aid, CPR, and oxygen administration certifications (within 24 months) are mandatory, along with a current diving medical signed by a physician.
• Divers must use an approved closed-circuit rebreather model and demonstrate proficiency with its operation during assessment.
• Always confirm that your chosen dive centre offers SSI CCR Hypoxic Trimix training and has access to suitable sites for extreme-depth dives.

Free registration

You can begin your eLearning by creating a free SSI account and affiliating with our dive centre here:
Register with Dorset Diving.

What’s next?

After completing CCR Hypoxic Trimix Diving, divers often progress toward SSI CCR Technical Instructor ratings or participate in expedition-level CCR projects, exploring deep wrecks and cave systems far beyond conventional limits.