CCR diving certification courses: how it goes and what you need to know

How a CCR Liberty Course Typically Proceeds

A quality CCR Liberty training track will resemble the following progression. Note: each training agency (e.g., DIVESOFT, partner instructor groups) may tailor it, but the structure should meet or exceed RTC (or equivalent) standards.

Prerequisites

Before enrolling, divers are typically expected to have:

• Advanced Open Water (or equivalent)
• Nitrox certification (Advanced Nitrox with stage cylinder recommended)
• Strong buoyancy control and trim
• A minimum number of logged dives often 30–50 (100 recommended)
• Recent diving activity
• Medical clearance as required

These ensure you’re ready for the cognitive load and risks CCR introduces.

Course Phases

1. 1. Classroom / Theory
      Theory is meant to prepare you for whatever the real world underwater has in store for you. You should be able to understand and fully grasp the principles of rebreather diving. You will study diving physiology (O₂ toxicity, CO₂ retention, hypoxia), gas control, loop mechanics, electronics, failure modes, emergency decision trees, and dive planning (diluent, bailout, decompression).
2. Confined Water / Pool Work
   In the pool, you will get used to new equipment that is so different from the device you are used to. In the confines of the pool, you will be safe and confident enough to try everything you need before you are exposed to the other influences of the real underwater world. Under instructor supervision, you practice:

• Loop pre-breathing, flood management, purge/clear procedures
• Manual PO₂ control (if applicable)
• Bailout drills (switching to open circuit)
• Buoyancy and trim control with full loop
• Simulated failures (sensor dropouts, flooding, etc.)

3. Open Water Dives
   Under the supervision of an experienced instructor, you will learn everything you need to know for self-sufficient diving with a rebreather in real conditions. You’ll execute a series of 8 dives —progressing in complexity and depth (commonly to 30 m for entry-level). Tasks include:

• Detailed pre-dive checklists
• In-water loop monitoring and adjustment
• Controlled ascents and gas switching
• Emergency responses (e.g. high PO₂, cell failure, flood)
• Post-dive checks, maintenance, sensor calibration, and data logging

4. Certification Debrief & Final Assessment
   You will be evaluated on theory, skills, emergency handling, and dive logs. The instructor confirms that you are competent and comfortable to proceed.

Timeframe is often 5–7 days, depending on your pace and local conditions.

Risks & Reality: Why Rigorous Training Is Non-Negotiable

CCR diving introduces hazards not encountered in open circuit: hypoxia, hyperoxia, hypercapnia, CO₂ retention, sensor failure, flooding, loop failures. Because of these, every CCR diver relies heavily on systematic habits, checklists, and overlearning of critical drills.

As experienced technical diver and educator Phil Short once put it:
“Training is not just about learning to operate the machine — it’s about learning to think like a rebreather diver.”
— Phil Short, explorer and diving educator (source)

That mindset — cautious, methodical, and self-aware — is what turns complex equipment into a safe tool for exploration. Therefore, your instructor, training syllabus, and continued practice after certification are your real life-zone of safety.

The Path of Progression

Once certified as an entry-level CCR Air Diluent Diver (40 m), you can progress to:
1. CCR Air Diluent Decompression (30 m)
2. CCR Air Diluent Decompression (40 m)
3. CCR Trimix (60 m) — introduces helium and decompression management
4. Advanced Trimix (100 m+) — for deep exploration and technical diving

Each step builds upon experience logged on your rebreather and expands both knowledge and confidence.

RTC & ISO: The Framework Behind Quality CCR Training

The Rebreather Training Council (RTC) brings together major training agencies to align minimum curricula and safety expectations for rebreather courses. RTC also works with manufacturers via CRISAG to align diver training and equipment considerations. Crucially, RTC holds Category C liaison status with ISO/TC 228 WG 1 (Diving Services) and contributed to drafting the ISO rebreather diver training standards now in force. rebreathertrainingcouncil.org+2rebreathertrainingcouncil.org+2

Current ISO standards for CCR diver training:

• ISO 24804:2022* — Rebreather diver training: No-decompression diving. Competencies for rebreather dives to 30 m without mandatory decompression using nitrox. iso.org+1
• ISO 24805:2022 — Rebreather diver training: Decompression diving to 45 m. Competencies for dives requiring decompression to 40 m on nitrox or to 45 m on trimix. iso.org+1
• ISO 24806:2023 — Rebreather diver training: Decompression diving to 60 m. Competencies for decompression dives to 60 m using helium-containing mixes. iso.org
• ISO 24807:2023 — Rebreather diver training: Decompression diving to 100 m. Competencies for decompression dives to 100 m using helium-containing mixes. iso.org

(As background, RTC had earlier published its own Level 1–3 technical standards; many agency syllabi map closely to these levels and now align with ISO.) rebreathertrainingcouncil.org+1

Why this matters: ISO/RTC alignment gives students and operators a common language—depth/gas limits, core skills, evaluation criteria—so your certification’s implications are clear when you travel or join new teams.

Explorer and educator Jill Heinerth puts it plainly:
“Training agencies have the opportunity to set the ground rules right from the beginning and guide divers to recognize that the general safety rules have been developed from practical experiences.” intotheplanet.com

That culture—standards, repeatable habits, and instructor accountability—turns complex equipment into a safe tool for exploration.

Training on Liberty: What to Look for If you choose to train using the Liberty rebreather, here are some criteria to keep in mind so your training is meaningful and future-proof: • Unit-specific instruction — CCR certification is machine-specific. If your training is on Liberty, that’s the unit you should continue to use (or do a crossover for others). • Redundancy & failure simulation — your course should include drills for sensor dropouts, loop flooding, solenoid malfunctions, etc. • Maintenance & calibration training — you should learn to inspect, replace, and calibrate O₂ sensors, scrubber media, and seals. • Extended scenario dives — look for courses that go beyond ideal conditions (currents, limited visibility, off-gassing complexity). • Emphasis on human factors & non-technical skills — your course should also teach judgement, situational awareness, communication, and error recognition. Post-certification, commit to regular practice, maintain checklists, retrofit firmware updates, and engage with the Liberty / CCR community to stay sharp.

Final Thoughts & Advice CCR Liberty diving holds tremendous promise — elegance, efficiency, and deeper exploration. But it is not a shortcut. The safety margin in rebreather diving is less forgiving than ever, so you must: 1. Choose a training provider that adheres to or exceeds RTC / ISO standards 2. Be ready for intensive theory, hands-on confined water, and challenging open-water drills 3. Treat checklists and emergency procedures as sacred 4. Practice regularly after certification 5. Respect your limits, and expand gradually Dive safe, stay curious — and let Liberty open new windows into the underwater world.

Author: Jakub Šimánek