Air Diluent CCR
Your entry point into closed-circuit rebreather diving as certified by Technical Diving International
ABOUT THE COURSE
This Technical Diving International’s course introduces the fundamentals of closed-circuit rebreather (CCR) diving for divers ready to move beyond open circuit and operate with more control, efficiency, and range underwater.
You’ll learn to dive a CCR using air or nitrox as diluent, focusing on disciplined procedures, precise system management, and calm decision-making. The goal is capability: building the skills and habits that make deeper, longer, and quieter dives possible.
WHO IS THIS COURSE FOR
For certified divers looking to advance their training and equipment by learning to dive a rebreather. Whether you’re an avid photographer, want to experience the silence of rebreather diving, or get closer to marine life – rebreather diving is for you.
PREREQUISITES
To apply for this course you must meet the following criteria:
- Minimum age: 18
- At least 20 logged open-water dives
- TDI Nitrox Diver certificate or (equivalent)
WHAT YOU'LL LEARN
This course focuses on understanding the rebreather system, managing breathing gas correctly, and responding effectively to failures, both in theory and in the water.
Theory and system knowledge
- How closed-circuit rebreathers work and how they differ from open circuit
- CCR assembly, setup, and post-dive maintenance
- Gas physiology, including oxygen and CO₂ management
- PPO₂ control and system monitoring
- Dive planning for CCR dives, including bailout considerations
- Use of dive computers in CCR diving
- Emergency procedures and failure management
- Team procedures and disciplined dive execution
In-water skills and training
Training includes confined water sessions and multiple open-water dives, with a gradual increase in depth and task loading.
You will practice:
- Pre-dive checks and system verification
- Buoyancy control and loop volume management
- PPO₂ monitoring and setpoint management
- Bailout procedures and emergency drills
- Stable, controlled CCR diving within defined limits
- Safe ascent procedures and safety stops
- Post-dive cleaning and basic unit care
WHAT’S IN IT FOR YOU
After successful completion, you will be certified to:
- Dive a closed-circuit rebreather using air or nitrox as diluent
- Dive to a maximum depth of 30 metres / 100 feet
- Conduct no-decompression CCR dives
- Dive independently within conditions similar to those encountered during training
COMPLETION REQUIREMENTS
To complete the course, you must:
- Pass the TDI CCR Air Diluent written exam (minimum score 80%)
- Demonstrate all required confined and open-water skills
- Show sound judgment in dive planning and execution
- 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.