Decompression Course

[KenGordon]

So there's a "gray area". OK. Let's take that at its word. In that gray area you're beneath a decompression ceiling and you have only one tank of gas. If something were to happen to the tank o-ring, valve, first stage or any of the LP hoses coming from that first stage and you still had something like 9 minutes of decompression left to do and no buddy in sight, what do you do in your "gray area" training?

You are arguing about two failures, losing your buddy and having an total gas loss. The training in the case of buddy loss is to surface. The training in case of gas loss is to go to you buddy. I guess you missed my joke about keeping your buddy where you can feel them.

 

[doctormike]

You are arguing about two failures, losing your buddy and having an total gas loss. The training in the case of buddy loss is to surface.

I don't understand. How can you surface if you are in a virtual overhead environment?

 

[kr2y5]

I don't understand. How can you surface if you are in a virtual overhead environment?

By "surface", he probably meant to say to "abort the dive" by initiating ascent and completing all required deco.

 

[DevonDiver]

welcome to the grey area club!

On any dive, you must have:

1) Sufficient gas to reach the surface safely.

2) Sufficient resources to mitigate any reasonably foreseeable problems which jeopardize point #1.

Depth, ascent time, deco obligation, overheads all fit into those two simple considerations.

"Safely" assumes correct ascent rate/profile, according to your dive planning, with no reasonably predictable risk of DCS occurrence.

CESA covers a lot of options. Beyond that [correct adherence to] the buddy system covers most others, where direct access to the surface is possible. Redundant and ample gas supply covers both buddy system failure and unplanned delays in ascent.

Where access to the surface is not possible (deco/overhead) point #2 becomes much more critical. You have to deal with any and all problems from beneath a ceiling. Training, experience, equipment and planning all come into this. Technical diving training provides this for certain. Few, if any, recreational level courses do so.

 

[rivers]

On any dive, you must have:

1) Sufficient gas to reach the surface safely.

2) Sufficient resources to mitigate any reasonably foreseeable problems which jeopardize point #1.

Depth, ascent time, deco obligation, overheads all fit into those two simple considerations.

"Safely" assumes correct ascent rate/profile, according to your dive planning, with no reasonably predictable risk of DCS occurrence.

CESA covers a lot of options. Beyond that [correct adherence to] the buddy system covers most others, where direct access to the surface is possible. Redundant and ample gas supply covers both buddy system failure and unplanned delays in ascent.

Where access to the surface is not possible (deco/overhead) point #2 becomes much more critical. You have to deal with any and all problems from beneath a ceiling. Training, experience, equipment and planning all come into this. Technical diving training provides this for certain. Few, if any, recreational level courses do so.

all of which I know and understand. My grey area comment was in reference to bergersau's IANTD deep diver course, which covered both your points. as does GUE's Rec 3. So there are at least 2 recreational courses that cover the planning, contingencies, gas needs, etc.

 

[DevonDiver]

all of which I know and understand. My grey area comment was in reference to bergersau's IANTD deep diver course, which covered both your points. as does GUE's Rec 3. So there are at least 2 recreational courses that cover the planning, contingencies, gas needs, etc.

I'm not really familiar with the training offered on either of those courses, so I won't dispute that. My point was merely the non-existence of a 'grey area' through the application of two analytical factors.

'Tecreational' level courses are now becoming more popular - breaching the gap between the traditional rec-tec divide. Nonetheless, those courses have specific aims and outcomes. It is wise not to over-attribute those outcomes, merely because they exceed prior definitions of 'recreational diving'.

Do either of the IANTD or GUE 'Rec 3' courses actually qualify divers to conduct decompression dives?

Or are they merely an instance of 'beginning with the end in mind'... pre-loading students with advanced knowledge of later training, to enable defter subsequent progression?

Giving someone the tools with which to practice and prepare for decompression diving, is not the same as training/qualifying them as decompression divers. For one thing, the required standards of skill performance and necessary acquired experience are likely to be noticeably lower in a 'preparatory' course, rather than a 'qualification' course.

 

[KenGordon]

I'm not really familiar with the training offered on either of those courses, so I won't dispute that. My point was merely the non-existence of a 'grey area' through the application of two analytical factors.

'Tecreational' level courses are now becoming more popular - breaching the gap between the traditional rec-tec divide. Nonetheless, those courses have specific aims and outcomes. It is wise not to over-attribute those outcomes, merely because they exceed prior definitions of 'recreational diving'.

Do either of the IANTD or GUE 'Rec 3' courses actually qualify divers to conduct decompression dives?

Or are they merely an instance of 'beginning with the end in mind'... pre-loading students with advanced knowledge of later training, to enable defter subsequent progression?

Giving someone the tools with which to practice and prepare for decompression diving, is not the same as training/qualifying them as decompression divers. For one thing, the required standards of skill performance and necessary acquired experience are likely to be noticeably lower in a 'preparatory' course, rather than a 'qualification' course.

I don't think anyone would claim that the BSAC Sports Dive course is 'Technical', however the lectures ST4 (Deeper Diving) and ST5 (Breathing Gas) together with the practical planning parts of the open water lesson cover mandatory decompressing diving. Unless a BSAC diver goes down the 'proper' technical route of ADP then mixed gas that is it for BSAC decompression training.

If I was completely bored I might dig out the TDI Advanced Nitrox and Decompression Procedures (which I expect most would call a technical course) manuals and see which bits about decompression are in there but missing from the Sports Diver one. I am sure there is a lot about team diving, general approach and mindset and so forth but about deco in particular I doubt there is much you need to know for single gas diving which is in one and not the other.

I'm only using BSAC and TDI as I am familiar with them, but from what has been said above it sounds like CMAS affiliates are similar to BSAC (and I suspect might have the same ISO standards numbers on their plastic cards).

I totally agree with points 1) and 2) about needing enough gas and having a way to deal with problems which may lead to not having enough gas. I think both those points apply to all divers all the time. 2 gets harder as complexity increases but there isn't a sharp transition from "anything goes" to "better be serious now". Personally I'd rather everyone took diving seriously. From a commercial perspective that was a hard sell. The old fashioned approach of extensive initial training before being allowed in open water, first level qualifications harder than today's second level failed when confronted with a system designed to get people in the water and having fun in a couple of weekends or at most during a week long holiday.

 

[mathauck0814]

Do either of the IANTD or GUE 'Rec 3' courses actually qualify divers to conduct decompression dives?

With IANTD, the Deep program is encouraged to be taught in conjunction with Advanced EANX or other class which DOES cover decompression. The deep course alone does not. (Forgive the formatting, copy and paste from a PDF doesn't appear to be seamless) Below is IANTD's Deep Diver Program from my Instructor Manual:

Deep Diver (OC, SCR, CCR)
Who may teach this course? An OW instructor who is at least Advanced Nitrox Diver certified or higher level of certification may
teach this course. [COLOR=rgb(0.000000%, 0.000000%, 100.000000%)]A Rebreather Instructor is required in order to certify a diver as a Rebreather Diver at this level.

[/COLOR]A. Purpose

2. This Program is designed to provide responsible training to divers who plan to dive to a maximum of 130 fsw (39 msw) on air.
3. The IANTD Deep Diver Program trains divers in skills, performance, theory and planning of deep dives. This Program remainswithin the commonly practiced depth of 130 fsw (39 msw), and is the first sanctioned international Program to provide proper
   training in safe deep diving skills and performance.
4. It is recommended that this Program be taught in conjunction with the IANTD EANx Diver Program or the Recreational Trimix
   Diver Program or the IANTD Advanced EANx Diver Program.
5. This program qualifies divers to dive to 130 fsw (39 msw).

B. Prerequisites

2. Must be qualified as an IANTD Advanced Open Water Diver or equivalent.
3. Must provide proof of a minimum of 10 logged dives.
4. Must be a minimum of 15 years of age with a parent or guardian authorization, or a minimum of 12 years of age for Junior
   Diver qualification, or a minimum of 18 years of age without guardian approval.

C. Program Content

2. All lectures completed with IANTD Course-specific Slides pertaining to the theory in the IANTD Deep Diver Student Kit.
3. This Program must include a minimum of 100 minutes of OW bottom time completed within 4 dives, two (2) of which must be to
   depths between 90 fsw (27 msw) and 130 fsw (39 msw).
4. (RB) All dives must be on rebreather.

D. Equipment Requirements
1. IANTD Deep Diver Student Kit.
[COLOR=rgb(0.000000%, 0.000000%, 100.000000%)]a. (RB) Rebreather divers at all course levels must have the IANTD CCR Diver “S” Drill chart C-3401.[/COLOR]

2. Same as Equipment requirements listed in the general Sport Diver Programs overview
3. Practice of gear configuration include redondancy, and streamlining. Proper tanks labeling with IANTD stickers
4. If the student has been qualified as an OW Side Mount Diver, Essentials or Self-sufficient Diver they may use the equipment
   trained on in those courses.
5. (RB) Student must own or have unlimited access to unit on which training is being held.
6. (RB) Must carry a minimum of 30 cubic feet (4 L) cylinder for bailout.

E. ProgramLimits

2. There may be no more than four (4) students per Instructor. This ratio may be increased by two (2) students for each assistingIANTD Dive Master, up to a maximum of 8 students with two (2) IANTD Dive masters per class session.
3. No dives may be conducted to depths greater than 130 fsw (39 msw).
4. No mandatory decompression stops are to be planned.
5. Appropriate safety decompression stops must be performed.

F. WaterSkillsDevelopment

2. (RB) Divers on CCR complete the IANTD “S” drill chart C-3401 prior to all water sessions. Others complete “S” drill procedures.
3. A confined water session must be completed before conducting any OW dives.
4. Swim in full underwater equipment for 5 minutes.
5. Calculate RMV from gas consumed during a 10-minute swim (based on change in cylinder pressure).
6. (RB) Divers cavalcade RMV for bailout OC gas.
7. Become proficient in the following propulsion techniques: modified flutter, modified frog, modified dolphin and standard shufflekicks.
8. (RB or Mixed Teams and OC) Demonstrate buoyancy control by combining with following skills.
   2. A timed ascent at a rate of 20 ft (6 m) per minute.
   3. Hover at constant depth for 3 minutes.

Copyright ©2010 by IAND, Inc. dba IANTD® All Rights Reserved 37 "The Leader in Diving Education[COLOR=rgb(0.000000%, 0.000000%, 50.196000%)]"[/COLOR]



7/7/2010Revision Date
[COLOR=rgb(0.000000%, 0.000000%, 100.000000%)]c. Swim 75 feet (23 meters) in full equipment without mask.[/COLOR]

2. Deploy a lift bag in less than two (2) minutes.
3. Swim in a simulated out-of-air situation (without breathing, and exhaling slowly) for a distance of at least 45 feet (14
   meters), and commence gas sharing. Swim for 200 feet (60 meters) while sharing gas. If the buddy is in on a rebreatherthen take the staged off board regulator and may have the RB diver hand the cylinder to the OC diver. Alternatively, have adiver hand off their bailout cylinder.
4. Once diver has calmed breathing on regulator or if buddy is OC diver take his regulator then continue to swim for at least200 feet (60 meters) while maintaining a normal swim rate; or appropriate Rebreather gas management drill for out-of airdiver.
5. Repeat the above step with the gas-recipient diver wearing a fully-flooded mask (or no mask at all), and swim two (2)minutes while sharing gas; or appropriate Rebreather gas management drill for out-of air diver.

2. (RB) Incorporate rebreather drills and review emergency skills found on Rebreather Standards. (For PSCR page 50 and forCCR page 52.)
3. Perform valve shutdowns: change regulators and shut the primary-regulator valve off, then reopen valve and repeat as if thesecondary (backup) regulator had malfunctioned. Repeat until skill (both valve openings shutdowns) is completed in less thantwo (2) minutes.
4. Close and open tank valves on all dives.
5. Deploy lift bag on at least two (2) occasions.
6. RemoveandreplacetankandBCDorrebreatheratsurfaceonatleastone(1)dive.
7. All ascents are to be at a rate of 30 feet (9 meters) per minute or slower
8. (RB ) On any black-out drills on a CCR the Instructor must know the PO2 on the student’s rig.

Recommended watermanship evaluation, to be completed during course (80% = passing [80 / 100 Points]).
This evaluation may be accomplished in one (1) session or during a sequence of training dives.
Skill One (25 points, to be completed in confined water)
Two buddies with blacked-out masks (or closed eyes) face each other at a distance of 50 feet (15 meters) apart, and follow a line or other referencetowards each other, without breathing. Upon contact, they commence gas sharing (alternate second stages or pony cylinder hand-off) and maintaincontact with each other while swimming for a distance of 900 feet (275 meters).


NOTE: All gas sharing drills are via the alternate second stage and not manual air sharing from the same secondstage.


Time (mm:ss) Points14 minutes or less 2514:01 to 14:20 2414:21 to 14:40 2314:41 to 15:00 2215:01 to 15:40 21
Skill Two (25 points)

Time (mm:ss)
18:01 to 18:20
18:21 to 18:40
18:41 to 19:00
over 19 minutes 00


Time (mm:ss) Points15:41 to 16:00 2016:01 to 16:15 1916:16 to 16:30 1816:31 to 16:45 1716:46 to 17:00 16

Time (mm:ss) Points17:01 to 17:15 1417:16 to 17:30 1217:31 to 17:45 1017:46 to 18:00 08

Points06


Ascend from a depth of at least 60 fsw (18 msw) at a rate of 30 feet (9 meters) per minute, plus a 10-minute safety stop at a depth of 15 fsw (4.5msw), with depth variation no greater than 3 fsw (1 msw) for the duration of the stop. The ascent is to be controlled via the BCD, not by pulling up aline. Score 25 points if performed correctly. Subtract one point for each one foot (0.3 meter) per minute variation in ascent rate during the overallaverage ascent to 15 (4.5 meters), and subtract 1 point each time the student changes depth by more than 3 fsw (1 msw) during the 10-minutesafety stop.
Skill Three (25 points)
Deploy a lift bag from a depth of 20 fsw (6 msw), and at least 30 fsw (9 msw) above the bottom. The diver must complete the deployment andmaintain depth within a maximum of ten feet (3 meters) variation (i.e., the diver cannot ascend to a depth shallower than 10 fsw [3 msw], or descendto a depth greater than 30 fsw [9 msw]) during deployment of the bag. Score 25 points if the skill is completed successfully, and subtract 5 points foreach depth variation greater than 10 fsw (3 msw).
Skill Four (25 points, confined water) Use of malfunctioning equipment:

2. Use a free-flowing regulator for 3 minutes.
3. Maintain buoyancy control via oral inflation of the BCD for five (5) minutes.

During this time, swim for a distance of at least 50 feet (15 meters) at one depth, then ascend by 3 fsw (1 msw) and repeat, then descend by 3 fsw (1msw) and repeat. This should be followed by a controlled ascent and controlled descent at a rate of no more than 10 fsw (3 msw) per minute, whileswimming in an area with a variation in depth. Score 25 points if all skills are completed successfully, and subtract 4 points for each violation ofprocedure on any of the skills, or if any skill needs to be repeated.

 

[Edward3c]

I'm only using BSAC and TDI as I am familiar with them, but from what has been said above it sounds like CMAS affiliates are similar to BSAC (and I suspect might have the same ISO standards numbers on their plastic cards).

Since when did CMAS get ISO certification? There is nothing about it on their Website.

 

[KenGordon]

Since when did CMAS get ISO certification? There is nothing about it on their Website.

Fair point, I did say *suspect* though and they do seem to be involved in the appropriate working group.

BTW, do you know why sports diver isn't certified to ISO 24801-2? I notice it specifies a knowledge of decompression limits rather than actual decompression practice and that PADI AOW complies.