ABOUT THE COURSE
This Technical Diving International’s course builds on your closed-circuit rebreather (CCR) foundation and introduces staged decompression diving on a closed-circuit rebreather. It’s the point where CCR diving shifts from no-stop profiles to planned decompression and longer, more demanding dives.
You’ll learn to conduct decompression dives using air diluent, extending depth and bottom time while maintaining precise control over gas management, buoyancy, and ascent strategy. The focus is on planning, discipline, and handling increased task loading in a controlled way.
WHO IS THIS COURSE FOR
This course is for divers who already have CCR experience and are ready to move into decompression diving, or for open-circuit technical divers transitioning to CCR.
It suits divers who want to stay longer, manage decompression efficiently, and operate comfortably in dives that require planning beyond recreational or no-stop limits.
PREREQUISITES
To apply for this course you must meet the following criteria:
- Minimum age: 18
- Minimum 50 logged dives
- TDI Advanced Nitrox Diver and TDI Decompression Procedures Diver (or equivalent)
- Sidemount certification and experience if using a sidemount CCR
OR
- Minimum age: 18
- TDI CCR Air Diluent Diver (or equivalent)
- Minimum 30 hours on the CCR unit
- At least 6 months of CCR diving experience
WHAT YOU'LL LEARN
Theory and system management
- Decompression theory and planning for CCR dives
- PPO₂ management throughout staged decompression
- Gas physiology with increased exposure and task loading
- Bailout planning and gas requirements for decompression dives
- CCR system configuration and maintenance for extended dives
- Use of dive computers and constant PPO₂ decompression planning
- Emergency management during decompression dives
In-water skills and training
Training includes confined water sessions and multiple open-water dives, progressing in depth and complexity.
You will practice:
- CCR dive planning with decompression obligations
- Precise buoyancy and loop volume control during ascents
- Setpoint switching and PPO₂ control
- Bailout procedures from depth, including simulated decompression
- Deployment and use of SMB / lift bag during decompression
- Managing failures during ascent and decompression
- Post-dive cleaning and unit maintenance
WHAT’S IN IT FOR YOU
After successful completion, you will be certified to:
- Conduct decompression CCR dives
- Use air diluent
- Dive to a maximum depth of 40 metres / 130 feet
- Dive independently within conditions similar to those encountered during training
COMPLETION REQUIREMENTS
To complete the course, you must:
- Pass the TDI CCR Air Diluent Decompression written exam (minimum 80%)
- Demonstrate all required confined and open-water skills
- Show sound judgment in dive planning, execution, and ascent control
- Meet all unit-specific and manufacturer requirements
A refresher is required after extended periods of inactivity, in line with TDI standards.
WHAT CCR MANUFACTURES ARE RECOGNIZED BY TDI?
TDI programs are recognized by a number of CCR manufactures worldwide. TDI is also member of RESA and is actively involved in the development of training standards. Below are the closed-circuit rebreather manufacturers that TDI and Ocean Explorers currently work with, along with letters of approval from each manufacturer.