PADI Deep Diver course- gas management

[Capt Jim Wyatt]

The gas management planning for this class is the responsibility of the instructor to "teach".

The class requires four dives over at a minimum two days. Dive one max depth = 100 feet. Dives 2, 3 and 4 max depth = 130 feet.

No stage decompression dives are allowed. Required equipment includes an emergency backup air supply. To meet this standard the instructor carries an AL40 with him/her.

It would not be an unreasonable plan for divers with AL80s filled to 3000 psi to leave the bottom with no less than 1200 psi and head to the 15 foot safety stop.

 

[tursiops]

Sounds like the whole coirse could really be consolidated down to one or two dives. Gas planning can be taught in the dry. What I feel is really needed is a controlled experience of "when do I personally get narced and what does it feel like".

I don't know why the course is 4 dives, except that it is far too much to do on 2 or maybe 3 dives, and four nicely fits a 2/day schedule for 2 days, plus classroom time (if done in a classroom).
All dives must be >60 ft. dive 3 is recommended to 130, and dive 4 is planned and executed by the student(s), with the instructor in attendance and having input-if-needed and veto-power over the plan.
The BIG take-away for the students on all four dives is how much faster their gas gets used up.
A secondary take-away is narcosis, possible on all four dives but likely on Dive 3.
Planning and execution to the plan is an overlay on all four dives, and paramount on Dive 4.
Another overlay -- and emphasized in the classroom work -- is the much higher possibly of DCS on deep dives and how you recognize it.
An emergency decompression stop is simulated on Dive 3.
Dive 2 includes a navigation exercise, away from and back to the descent/mooring line, which tests multi-tasking when possibly narced.

 

[Capt Jim Wyatt]

Capt Jim answered it, PADI does not define what "appropriate gas management" is, in the Deep Diver course.

That is true if you expect the numbers be laid out in the standards. But as @tursiops pointed out when he pasted:

Plan and manage gas use, including determining turn pressure, ascent pressure and reserve pressure. Establish no stop and dive time limits.In the briefing for Deep Dive One, it is suggested to:
5. Have buddy teams plan their turn pressure, ascent pressure and reserve pressure for the dive based on gas supply limits.6. Have buddy teams establish maximum depths and bottom times, and plan and plan contingency profiles for longer and deeper dives than planned.A performance standard for Deep Dive One is specifically about gas management:
a. Before beginning the descent, remind divers to check their starting pressure and make a note of their turn pressure.b. During the dive, check cylinder pressures at irregular intervals to confirm appropriate gas management.

Planning is done and I can defend that as appropriate gas management as is described.

 

[boulderjohn]

It is Parr of the discussion: exactly how it is discussed is up to the instructor.

This is consistent with how PADI does many things. When there are choices, it leaves the choices up to the instructor. For example, the language in the OW course dealing with alternate air sources is intentionally vague enough to allow any of the methods and equipment choices that are commonly used.

When I taught the course, I taught the different ways to plan their reserves, and we discussed the pros and cons of each. One of the choices I taught was Rock Bottom.

 

[tursiops]

Dive one max depth = 60 feet

Typo. Dive 1 max depth is 100 ft.

 

[Capt Jim Wyatt]

Typo. Dive 1 max depth is 100 ft.

Yes...I edited it just now to show 100 feet. Thank you.

 

[boulderjohn]

I don't know why the course is 4 dives, except that it is far too much to do on 2 or maybe 3 dives, and four nicely fits a 2/day schedule for 2 days, plus classroom time (if done in a classroom).

My guess to the reason can be exemplified by an experience I had doing the AOW deep dive with two friends. We did the dive off of a boat in South Florida, asking on a reef dive to be dropped off on the deep end, and we reached about 88 feet. My two friends were a little apprehensive before the dive, but within about 10 minutes of the dive, that was all gone. We later did the whole deep diver course, and they were comfortable as could be on the last dives.

 

[Leatherboot69]

This is consistent with how PADI does many things. When there are choices, it leaves the choices up to the instructor. For example, the language in the OW course dealing with alternate air sources is intentionally vague enough to allow any of the methods and equipment choices that are commonly used.

When I taught the course, I taught the different ways to plan their reserves, and we discussed the pros and cons of each. One of the choices I taught was Rock Bottom.

And of course these are training standards, rather than a manual. I recognise the general format of course and lesson planning from teaching, military training and other outdoor qualifications. Instructors are meant to use their own professional judgement to put together a lesson, right? It’s kind of normal in any structured training.

 

[jborg]

How/where are the instructors intended to learn the various gas planning methods they are supposed to teach? Do they need to take one of the Tec courses to learn about the gas planning to teach in Deep, if it's not included in the material for Deep itself?

 

[Leatherboot69]

Deep Diver specialty instructor course (10 logged dives plus training from a Course Director) or equivalent experience (25 logged dives)

The Encyclopedia of Recreational Diving, which contains all of this information and is required reference material for all PADI professionals.

Deep Diver e-learning, and their own Deep Diver course if they’ve attended it.

Recreational diving is a safe, relatively simple activity; 10 year olds can do it. Conditions (such as deep diving) add layers of risk and complexity but let’s be clear that this isn’t the Apollo moon landings. Gas planning for a rec dive to 40m requires understanding and applying some basic concepts (eg rule of thirds) and/or four or five calculations at a junior high school level of mathematics. This isn’t a course for divers applying advanced levels of skill, making particularly complex dives or for tec divers-it’s for doing simple rec dives in deeper and slightly more complex conditions.