This is the second entry level certification course for divers wishing to utilize a closed-circuit rebreather (CCR) for mixed gas diving using a Helitrox diluent. The objective of the course is to train divers in the benefits, hazards and proper procedures for diving a CCR and to develop basic CCR diving skills, to a maximum of 45 Metres, using an Trimix diluent for formal decompression diving. Students are permitted to utilize a diluent and bailout mix with no greater than a 35% helium content (+/- 5%) and no less than a 20% oxygen content and are permitted to use up to 100% oxygen for decompression.
mCourse Prerequisites
- Minimum age 18
- Provide proof of 50 logged dives. If completing a unit crossover, provide proof of 10 logged CCR dives in the last 12 months
- Minimum certification level of TDI Advanced Nitrox Diver, Deco Procedures Diver or Helitrox diver or equivalent from agencies recognized by TDI
- Provide proof of at least 5 logged staged decompression dives to a minimum depth of 30 metres/100 feet
OR
- Minimum age 18
- TDI Air Diluent CCR Diver certified or equivalent
- Minimum of 30 hours and 30 dives on the CCR unit
- Six months CCR diving experience
What you can expect to learn:
Understanding the Theory of CCR Diving
– Basic CCR principles, breathing loop mechanics, and gas behavior
Breathing Gas Limits
– Understanding safe oxygen exposure, nitrogen limits, and depth-related gas restrictions
Electronics Overview, Safety Protocols, and O₂ Cell Function
– How the controller and sensors work, safety systems, and essential pre-dive checks.
Disassembly, Assembly, and Detailed Understanding of JJ-CCR Parts and Function
– Full unit breakdown and setup, correct assembly, and recognizing each component’s role.
Possible Configuration Options and Trim Adjustments
– Different equipment setups, accessory options, and achieving stable, efficient trim.
Understanding Decompression Profiles and Choosing the Right Strategy
– How decompression works on CCR, gradient factors, and selecting safe dive plans.
Planning and Conducting Decompression Dives Within Safe Limits
– Practical dive planning, gas choices, bailout requirements, and conservative limits.
Bailout Strategy and Gas Management at Various Depths
– Emergency planning, calculating bailout needs, and managing gases effectively.
Manually Operating the Rebreather and Responding to Unit Failures
– Manual control techniques and correct reactions to common malfunction scenarios.
Diving as a Team and Safety Procedures During Decompression Dives
– Team communication, shared emergency planning, and coordinated decompression protocols.
Conducting Dives to a Maximum Depth of 45 m Using Helium Blends
– Using trimix/helium diluent safely, depth planning, and procedures for deeper CCR dives.
Equipment Requirements:
- Drysuit
- Minimum 2 stage cylinders
- Back up mask, cutting tools, buoy etc.