Rebreather training organized around your unit and objective.

• Minimum age: 18.
• Proof of 20 logged open-water dives; for a unit crossover, 10 logged CCR dives within the previous 12 months.
• TDI Nitrox Diver certification or equivalent.
• Nitrox Diver and/or Advanced Nitrox Diver may be combined with this course.

• History and evolution of rebreathers.
• Comparison of open-circuit, closed-circuit and semi-closed-circuit rebreather systems.
• Practical mechanics of the unit-specific system.
• Gas physiology.
• Scrubber packing in accordance with the manufacturer’s recommendations.
• Electronic or manual system design and maintenance.
• Dive tables, dive computers and dive planning.
• Emergency procedures.

• Build the unit to the manufacturer’s specifications using its manual and build checklist.
• Complete pre-dive checks and verify diluent and oxygen-cylinder contents with an oxygen analyzer.
• Demonstrate correct pre-dive planning and emergency procedures.
• Use the BCD or suit and manage breathing-loop volume effectively for buoyancy control.
• Stop at 3–6 metres / 10–20 feet during descent for a leak and bubble check.
• Monitor PO₂, change setpoints and, where applicable, control the setpoint manually.
• Use and adjust heads-up displays and dive computers.
• Remove and replace the mask.
• Deploy a lift bag or delayed surface marker buoy and reel where relevant.
• Execute the dive within all predetermined limits and complete required safety or decompression stops.
• Maintain constant loop volume and validate oxygen cells using diluent and oxygen appropriately.
• Clean and perform diver-level maintenance on the unit after the dive.

• Minimum age: 18.
• Proof of 50 logged dives; for a unit crossover, at least 10 logged CCR dives within the previous 12 months.
• TDI Advanced Nitrox Diver and Decompression Procedures Diver certifications, or equivalents recognized by TDI.

• History and evolution of rebreathers.
• Comparison of open-circuit, closed-circuit and semi-closed-circuit rebreather systems.
• Practical mechanics of the unit-specific system.
• Gas physiology.
• Scrubber packing in accordance with the manufacturer’s recommendations.
• Electronic or manual system design and maintenance.
• Dive tables, dive computers and dive planning.
• Emergency procedures.

• Build the unit to the manufacturer’s specifications using its manual and build checklist.
• Complete pre-dive checks and verify diluent and oxygen-cylinder contents with an oxygen analyzer.
• Demonstrate correct pre-dive planning and emergency procedures.
• Use the BCD or suit and manage breathing-loop volume effectively for buoyancy control.
• Stop at 3–6 metres / 10–20 feet during descent for a leak and bubble check.
• Monitor PO₂, change setpoints and, where applicable, control the setpoint manually.
• Use and adjust heads-up displays and dive computers.
• Remove and replace the mask.
• Deploy a lift bag or delayed surface marker buoy and reel where relevant.
• Execute the dive within all predetermined limits and complete required safety or decompression stops.
• Maintain constant loop volume and validate oxygen cells using diluent and oxygen appropriately.
• Clean and perform diver-level maintenance on the unit after the dive.

• Minimum age: 18.
• Proof of 50 logged dives; for a unit crossover, 10 logged CCR dives within the previous 12 months.
• TDI Advanced Nitrox Diver and Decompression Procedures Diver, TDI Helitrox Diver, or an equivalent recognized by TDI.

• History and evolution of rebreathers.
• Comparison of open-circuit, closed-circuit and semi-closed-circuit rebreather systems.
• Practical mechanics of the unit-specific system.
• Gas physiology.
• Scrubber packing in accordance with the manufacturer’s recommendations.
• Electronic or manual system design and maintenance.
• Dive tables, dive computers and dive planning.
• Emergency procedures.
• Helium considerations.

• Build the unit to the manufacturer’s specifications using its manual and build checklist.
• Complete pre-dive checks and verify diluent and oxygen-cylinder contents with an oxygen analyzer.
• Demonstrate correct pre-dive planning and emergency procedures.
• Use the BCD or suit and manage breathing-loop volume effectively for buoyancy control.
• Stop at 3–6 metres / 10–20 feet during descent for a leak and bubble check.
• Monitor PO₂, change setpoints and, where applicable, control the setpoint manually.
• Use and adjust heads-up displays and dive computers.
• Remove and replace the mask.
• Deploy a lift bag or delayed surface marker buoy and reel where relevant.
• Execute the dive within all predetermined limits and complete required safety or decompression stops.
• Maintain constant loop volume and validate oxygen cells using diluent and oxygen appropriately.
• Clean and perform diver-level maintenance on the unit after the dive.

• Minimum age: 18.
• A verified minimum of 50 rebreather hours across at least 50 dives on the specific unit. Qualifying dives must be deeper than 9 metres / 20 feet; at least 20 must be deeper than 30 metres / 100 feet and at least 10 must require staged decompression.
• A diver with 50 hours on another TDI-recognized CCR needs at least 25 hours and 25 dives on the course-specific unit.
• For a unit crossover, at least 10 logged CCR dives within the previous 12 months.
• TDI Air Diluent Decompression Procedures Rebreather or TDI CCR Helitrox Diluent Decompression Procedures certification, or an equivalent recognized by TDI.

• Gas physiology and formula work.
• Dive tables, dive computers and decompression on a CCR.
• Dive planning and the unit-specific checklist.
• Equipment maintenance and loop configuration.
• Additional fitted equipment and modifications.
• Emergency procedures.

• Build the unit to the manufacturer’s specifications and demonstrate command of basic and intermediate hand signals.
• Select and prepare equipment for a soft overhead environment with long decompression obligations.
• Conduct team-oriented lift-bag, bailout and buddy-rescue drills.
• Analyze every gas mixture, complete detailed dive planning, use the TDI pre-flight checklist and perform START before every dive.
• Apply stress analysis and mitigation while maintaining communication, proximity and team awareness.
• Maintain precise buoyancy and hover without moving hands or feet; remove and replace the mask and deploy a backup mask.
• Recover from a system failure and complete the dive and decompression using carried open-circuit gases.
• Connect, share and exchange off-board gas and bailout cylinders.
• Recover from system failure and complete the dive and decompression with the unit in manual mode.
• Respond to gas shutdowns, loss of gas, broken hoses, catastrophic failures, a flooded scrubber and cell errors.
• Complete a minimum ten-minute SCR drill and use oxygen-rebreather mode shallower than 6 metres / 20 feet.
• Manage two bailout cylinders, including drop and recovery while holding position in the water column.
• Deploy a DSMB at depth and in mid-water and respond to a simulated failed deployment.
• On two dives, ascend with an ascent reel and lift bag while completing staged decompression.
• Monitor PO₂, validate cells, remain within planned limits and hold decompression stops at predetermined depths.
• Conduct a controlled ascent with a simulated oxygen-toxicity casualty, tow the diver at least 50 metres / 165 feet and remove equipment at the surface in water too deep to stand.

• Minimum age: 18.
• TDI CCR Mixed Gas Diluent Diver certification or an equivalent recognized by TDI.
• A verified minimum of 100 CCR hours across at least 100 dives, including at least 50 hours and 50 dives on the course-specific unit.
• At least 50% of the qualifying dives must be deeper than 30 metres / 100 feet, and at least 20 logged CCR dives must require staged decompression.
• All qualifying dives must be deeper than 9 metres / 20 feet.

• Gas physiology and formula work.
• Dive tables, dive computers and decompression on a CCR.
• Dive planning and the unit-specific checklist.
• Equipment maintenance and loop configuration.
• Additional fitted equipment and modifications.
• Emergency procedures.

• Build the unit to the manufacturer’s specifications and demonstrate command of basic and intermediate hand signals.
• Select and prepare equipment for a soft overhead environment with long decompression obligations.
• Conduct team-oriented lift-bag, bailout and buddy-rescue drills.
• Analyze every gas mixture, complete detailed dive planning, use the TDI pre-flight checklist and perform START before every dive.
• Apply stress analysis and mitigation while maintaining communication, proximity and team awareness.
• Maintain precise buoyancy and hover without moving hands or feet; remove and replace the mask and deploy a backup mask.
• Recover from a system failure and complete the dive and decompression using carried open-circuit gases.
• Connect, share and exchange off-board gas and bailout cylinders.
• Recover from system failure and complete the dive and decompression with the unit in manual mode.
• Respond to gas shutdowns, loss of gas, broken hoses, catastrophic failures, a flooded scrubber and cell errors.
• Complete a minimum ten-minute SCR drill and use oxygen-rebreather mode shallower than 6 metres / 20 feet.
• Manage two bailout cylinders, including drop and recovery while holding position in the water column.
• Deploy a DSMB at depth and in mid-water and respond to a simulated failed deployment.
• On two dives, ascend with an ascent reel and lift bag while completing staged decompression.
• Monitor PO₂, validate cells, remain within planned limits and hold decompression stops at predetermined depths.
• Conduct a controlled ascent with a simulated oxygen-toxicity casualty, tow the diver at least 50 metres / 165 feet and remove equipment at the surface in water too deep to stand.

No. We review the unit, certification level, logged experience and applicable agency and manufacturer requirements before planning a crossover. Moving to a different unit and progressing to a more advanced diving level are separate training objectives.

Your qualifications, recent unit-specific experience and performance determine the appropriate course and schedule. Required dives, in-water time and skills must be completed; extra training days may be needed. Review the inclusions and exclusions below when planning your budget.

Choose your course and preferred dates on the training reservation page. Confirm the rebreather model, existing qualifications and course objectives with us before finalizing the plan. For a unit crossover or CCR cave training, discuss your experience with us first so we can identify the appropriate pathway.