The highest level of Closed Circuit Rebreather (CCR) training that
TDI offers, the Advanced Mixed Gas Course will teach you how to use
the full capabilities of a CCR.
With a maximum depth of 100 metres/330 feet, this course opens up a
whole new realm of diving including new wrecks, caves and walls to explore
in depths you previously could
not reach on a rebreather. This intensive course conducted over seven
dives will focus on all the elements needed to plan and execute dives
to these depths.M
The certified TDI Mixed Gas CCR Diver (or equivalent) looking to extend their depth limitations
Minimum age of 18
Certified TDI CCR Mixed Gas Diluent diver, or equivalent from agencies
recognized by TDI
Have verified logs of a minimum of 100 hours as a certified CCR diver
over a minimum of 100 dives; a minimum of 50 hours and 50 dives must
be on the unit specific CCR.
Fifty percent of these dives must be deeper than 30 metres/100 feet.
All dives to be deeper than 9 metres/20 feet
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 (out)
Gas management
Dive tables Creation of custom dive tables appropriate to dive depths
Creation of lower percentage 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
No dives deeper than 100 metres/330 feet
No dives shallower than 40 metres/130 feet other than the 1 air diluent
configuration dive
Equivalent narcosis depth not to exceed 30 metres/100 feet
Calculate all off-board gas at litres 45.30/1.06 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
Conduct pre-dive checks using TDI Pre-flight checklist
Use START* before every dive
Stress analysis and mitigation
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 gas switching
procedure
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 (setpoint)
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)
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 a 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, disaster scenarios
Flooded absorbent canister
Cell errors
SCR drill (minimum of 10 minutes)
Oxygen rebreather mode in depths less than 6 metres / 20 feet
Manually control CCR Unit for one full dive including all decompression
stops
Demonstrate competence managing 3 bailout cylinders, including drop
and recovery while maintaining position in the water column
Demonstrate proper understanding and implementation of team bailout
procedures and conduct a team bailout from a depth greater than 40 metres/130ft
Demonstrate ability as a team to plug in and share off-board gas, including
team sharing/swapping of off-board bailouts
On 2 of the dives, demonstrate an ascent with ascent reel and lift bag
and perform staged decompression
Proper execution of the dive within all pre-determined dive limits
Ability to manage multiple failures in adverse conditions
Demonstrate of surface support/support divers in dealing with bailout
scenarios
Upon successful completion of this course, graduates may engage in
technical diving activities utilizing the unit specific CCR to a maximum
depth of 100 metres/330 feet utilizing any mixed gas diluent appropriate
to the dive plan provided: The diving activities approximate those of
training
The areas of activities approximate those of training
Environmental conditions approximate those of training
Complete to the instructor’s satisfaction all in 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