tdi advanced mixed gas closed circuit rebreather diver course

TDI CCR Mixed Gas Diver

As a TDI CCR Air Diluent Decompression or Helitrox Diluent Decompression Diver, the TDI Mixed Gas CCR Diver course is your next step into closed circuit rebreather diving,
it is your opportunity to explore a little deeper. Using the latest in technology CCR’s maximize your gas supply and provide the optimum breathing gas for any depth by maintaining
a constant partial pressure of oxygen (PPO2). During the dives your TDI Instructor will teach you all the necessary skills to conduct CCR dives utilizing helium as a diluent gas
and oxygen levels as low as 16 percent to a maximum depth of 60 metres/200 feet.

Who this course is for:

The certified TDI Air Diluent Decompression or Helitrox Diluent Decompression Diver (or equivalent) looking to extend their depth limitations.

Course prerequisites:

Minimum age 18
Provide a verified log of a minimum of 50 rebreather hours distributed over a minimum of 50 dives on the specific rebreather.
If the diver has 50 hours on another CCR unit recognized by TDI, only 25 hours are required to be on the specific unit
Have completed and qualified the TDI Air Diluent Decompression Procedures Rebreather/TDI CCR Helitrox Diluent Decompression Procedures Diver course or equivalent from agencies recognized by TDI

What you can expect to learn:

The TDI Diving Rebreathers Student Manual is required for use as a review/recap document. The instructor may use any additional text or materials they feel will represent the topic in an
educational manner. The following topics must be covered during the course:
Gas physiology Oxygen (O2) toxicity
Hypoxia
Nitrogen absorption
Helium absorption
HPNS
Carbon dioxide (CO2) toxicity
Gas consumption
Gas mixing

Formula Work Oxygen (O2) metabolizing calculations
Manually controlled closed circuit rebreathers
Equivalent narcosis depth theory
Central nervous system (CNS) tracking
Oxygen tracking units (OTU)
Gas management

Dive tables Creation of custom dive tables appropriate to dive depths
Creation of lower percentage of oxygen (PO2) diluent to support loop flushing and bailout at depth

Dive computers Mix adjustable
Constant partial pressure of oxygen (PPO2)
Oxygen (O2) integrated

Dive planning Operational planning

Equipment maintenance Fuel cell management
Loop configurations
Additional fitted equipment and modifications

Required Skill Performance and Graduation Requirements

The following open water skills must be completed by the student during open water dives with the following course limits
No dives deeper than 60 metres/200 feet
No dives shallower than 40 meters/130 feet, other than the 1 air diluent configuration dive are credited toward the dive requirements.
Subsequent training dives in shallow water are permitted if necessary during the course
Equivalent narcosis depth not to exceed 30 metres/100 feet
Calculate all off-board gas at 45.30 litres/1.06 cubic feet per minute usage to cover stress situations
PO2 not to exceed manufacturer recommendation or a working limit of 1.3 bar during the bottom phase of the dive and 1.4 bar during the decompression phase of the dive
Diluent PO2 should not exceed 1.2 at maximum depth
All dives to be completed within appropriate fixed PO2 decompression tables or decompression planning software
All dives to be completed within CNS percentage limits with a recommend maximum of 80 percent of the total PO2 CNS limit
The student is only certified for CCR mixed gas diving on the rebreather being used

Land Drills

Build unit based on manufacturer’s specifications using manufacturer’s manual/build checklist
Demonstrate familiarity with basic and intermediate hand signals
Select and prepare equipment suitable for soft overhead environment with long decompression obligations
Conduct team oriented drills for lift bag deployment and bailout procedures
Drills for buddy rescue
Properly analyze all gas mixtures to be used
Demonstrate adequate pre-dive planning
Limits based on system performance
Limits based on bailout gas requirements
Limits based on oxygen exposures at chosen PPO2 levels
Limits based on manually controlled closed circuit rebreathers
Limits based on nitrogen absorption at planned depth and PPO2 (set-point) level
Limits based on helium absorption
Correct narcotic depth planning and diluent selection to allow cell flushing at target depth (diluent should not exceed a PO2 of 1.2 at maximum planned depth)

Pre-dive Drills

Conduct pre-dive checks using TDI Pre-flight checklist
Use START* before every dive
Stress analysis and mitigation

Open Water Skills

Show good awareness of buddy and other team members through communications, proximity and team oriented dive practices
Demonstrate buoyancy control; ability to hover at fixed position in water column without moving hands or feet
Properly execute a recovery from a system failure and conclude the dive and decompression on open circuit gases carried
Properly execute a recovery from system failure and conclude the dive and decompression with the unit in manual mode
Gas shutdowns and loss of gas, correct choice and switching to off board gases
Broken hoses, catastrophic failure scenarios
Flooded absorbent canister
Cell errors
SCR drill (minimum of 10 minutes)
Oxygen rebreather mode in depths less than 6 metres/20 feet
Stop at 3 to 6 metres/10 to 20 feet on descent for leak bubble check
Demonstrate competence managing 2 bailout cylinders, including drop and recovery while maintaining position in the water column
Deployment of a lift bag/delayed surface marker buoy (DSMB) at depth and mid water
Simulate failed lift bag/DSMB deployment
On 2 of the dives, demonstrate an ascent with ascent reel and lift bag and perform staged decompression
Electronics systems monitoring for PPO2 levels
Proper execution of the dive within all pre-determined dive limits
Demonstration of decompression stops at pre-determined depths
Demonstrate controlled ascent with toxed diver including surface tow at least 30 metres/100 feet with equipment removal on surface, in water too deep to stand in

What’s in it for you?

Upon successful completion of this course, graduates may engage in technical diving activities utilizing the unit specific CCR to a maximum of 60 metres / 200 feet,
utilizing a mixed gas diluent containing 16 percent or greater oxygen provided:
The diving activities approximate those of training
The areas of activities approximate those of training
Environmental conditions approximate those of training
Ability to enroll on TDI Advanced Wreck Course

TDI CCR Mixed Gas Diver minimum requirements:

Complete to the instructors satisfaction all confined and open water skill development sessions
Demonstrate mature, sound judgment concerning dive planning and execution
Course must be completed within 6 weeks from the starting date
Complete a refresher course following a period of inactivity greater than 6 months following the course