Issues with CCR standards

[World HQ SDI/TDI/ERDI]

Dave,

Thank you for bringing your concerns about the CCR Mixed Gas standards to our attention. Our ears are always open when it comes to interpretation of our standards, and we regularly release training updates to our membership clarifying any potential misunderstandings. The standards you have pointed out are not new points, however, and have actually remained unchanged since 2008, and many instructor and instructor trainers have been using these specific points to train thousands of Mixed Gas CCR divers. We typically do not like to post training standards in public forums as they are written in a way for instructors who are trained in our philosophies to read and interpret them correctly. However, we would like to post the specific sections you noted as to keep them in context and explain where the confusion may lie. Comments are in red.


The following open water skills must be completed by the student during open water dives
with the following course limits:

1. No dives deeper than 60 metres / 200 feet
2. No dives shallower than 40 meters / 130 feet, other than the 1 air diluent configuration dive
3. Equivalent narcosis depth not to exceed 30 metres / 100 feet
4. Calculate all off-board gas at 45.30 litres /1.06 cubic feet per minute usage to cover stress situations

This is meant to be a MINIMUM requirement, it does not state that it is required to use 1.06 cf/min. PLUS thirds.It also does not state that you are not allowed to calculate SAC rates and verify gas requirements.

1. 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
   Because the statement is made in the context of the rebreather manufacturer’s recommendations, it is implied that this standard relates to the setpoint.The skill requirements below actually require the student to demonstrate the ability to operate in O2 CCR mode shallower than 20’.There is no problem performing O2 flushes to validate cells, the standard is only implying planning to run a max setpoint of 1.3 on the bottom and 1.4 for deco.This also does not address OC PO2s, normal OC PO2 limits apply to the course.
2. All dives to be completed within appropriate fixed PO2 decompression tables
3. All dives to be completed within CNS percentage limits with a recommend maximum of 80 percent of the total PO2 CNS limit
4. The student is only certified for CCR mixed gas diving on the rebreather being used.
   
   Open Water Skills:
5. Verify diluent and O2 cylinder contents using O2 analyzer where appropriate
6. Demonstrate correct pre dive planning procedures including:
   1. Limits based on system performance
   2. Limits based on oxygen exposures at chosen PPO2 levels
   3. Limits based on manually controlled closed circuit rebreathers
   4. Limits based on nitrogen absorption at planned depth and PPO2 (setpoint) level
   5. Limits based on helium absorption
   6. Correct narcotic depth planning and diluent selection to allow cell flushing at target depth
7. Properly execute a recovery from a system failure and conclude the dive and decompression on open circuit gases carried
8. Gas shutdowns and loss of gas, correct choice and switching to off board gases
9. Broken hoses, disaster scenarios
10. Flooded absorbent canister
11. Oxygen rebreather mode in depths less than 6 metres / 20 feet
12. Controlled use of BCD/suit for buoyancy control
13. Pre dive checks
14. Stop at 3 to 6 metres / 10 to 20 feet on descent for leak bubble check
15. Remove and replace side mounted stage cylinders under water
16. Deployment of a lift bag / delayed surface marker buoy (DSMB) at depth and mid water
17. Electronics systems monitoring for PPO2 levels
18. Proper execution of the dive within all pre-determined dive limits
19. Demonstration of decompression stops at pre-determined depths
20. Post dive clean of unit to avoid contamination and spread of disease

To address Dive-aholic’s comment regarding the Rebreather Cave Standards, those standards are a bit clearer regarding BO requirements:
1. Diver carries adequate bailout to safely exit from the furthest point of penetration and complete any
decompression stops using a minimum SAC rate of 30 litres per minute/1 cubic foot per minute OR the
student’s calculated elevated SAC rate to account for a CO2 event, whichever is greater
Also keep in mind, the Rebreather Cave standards are brand new, whereas the CCR Mixed Gas standards are almost 6 years old, which may be why the language is a little clearer.

In response to the last comment in Dave’s original post: “The limits imposed by the new standards are just too restrictive. How about letting your instructors do what we are trained to do without imposing unrealistic limitations?”
Once again, these are not “new” standards; they have been in effect for almost six years, and are noted in the copy written standards (from 2009) you have posted on your own website (Training Courses Available). We do appreciate the feedback and will take the comments into consideration when looking at revisions in 2014.

 

[wedivebc]

Dave,

Thank you for bringing your concerns about the CCR Mixed Gas standards to our attention. Our ears are always open when it comes to interpretation of our standards, and we regularly release training updates to our membership clarifying any potential misunderstandings. The standards you have pointed out are not new points, however, and have actually remained unchanged since 2008, and many instructor and instructor trainers have been using these specific points to train thousands of Mixed Gas CCR divers. We typically do not like to post training standards in public forums as they are written in a way for instructors who are trained in our philosophies to read and interpret them correctly. However, we would like to post the specific sections you noted as to keep them in context and explain where the confusion may lie. Comments are in red.

Thank you for clearing that up for me. I don't actually recall seeing this issue discussed in any training bulletin and I do read them and save them for future reference so I must have somehow missed it. If you could direct me to that specific bulletin it may be of help.
I would like to point out that I am an instructor trained in interpreting TDI philosophy and was not clear on the interpretation of this one which is why I sought help on a public forum.
I do believe the training standards are the legal basis that our conduct as instructors is directed by. It does give me concern when you use the word implied when referring to training standards and since your implication was lost on me, an active technical instructor I would be worried that it might also be lost in a court of law where the distinction between OC and CC might not be as clear to others.