PADI Deep Diver course- gas management

[Lorenzoid]

Your memory of a course 18 years ago is interesting, but probably not very relevant to someone taking the class today from a different instructor.
My response was what the PADI Instructor Manual says, today.
Whether a particular instructor meets that standard, ignores it, or goes beyond it, is the key issue.
Anyone thinking to take the class would be advised to discuss with the instructor -- before the class -- how gas management will be addressed. The background do do this should have been obtained in the student's AOW class, which is a prereq for Deep.

Good advice. Sometimes, as you know, a shop will assign an instructor at the last minute. I had no idea who my instructor would be when I took the Deep course in 2012--I just signed up, expecting I would be taught everything I needed to know. I had lucked out with being taught an excellent Rescue course in 2004 and had no reservations about taking another PADI course. But discussing things beforehand with one's prospective instructor is not always as easy or expected as it is in the tech diving realm. I don't think "gas management" was even in my vocabulary, and I wouldn't have had any idea what to ask.

Similarly to what I believe @Divin'Papaw describes, in my Deep course I learned a diver could choose to do this, or a diver could choose to do that, and the bottom line is to reserve enough gas for the dive you're doing. Okay. The silver lining of my Deep course was that my resulting frustration is what prodded me to seek training that might give me more concrete direction. (Some might say GUE hits you over the head with that concrete, but being told to "do it this way for present purposes" is exactly what I wanted.)

 

[jadairiii]

Not sure exactly what you want. Gas management is part of the bookwork, classwork, and each of the four dives. The overriding principle is:

Plan and manage gas use, including determining turn pressure, ascent pressure and reserve pressure. Establish no stop and dive time limits.​

The Deep manual goes into gas consumption. calculating planned usage, etc. The fundamental constraint is maintaining a reserve pressure.

That's great. Regarding the "reserve pressure", do they reference the reserve pressure for both diver and buddy or just diver? Just wondering how close it is to GUE? GUE, all of the gas management is based on the possibility of an emergency and getting you and your buddy to the surface, with deco and/or safety stop. Reserve pressure is for both divers.

I was a PADI AI but we are talking 1982. Been awhile since I looked at a PADI manual.

And, this is not a GUE vs PADI and not intended to bash PADI, just wondering and I can give this kid some pointers as he takes his PADI deep diver class.

 

[johndiver999]

I would be surprised if the relevant information necessary to make a deep dive to 130 ft within the nodeco limits is not included in the training materials. If someone is worried that the instructor will not emphasize that info, it should be easy to work with the deep diver student on the simple math to ensure comprehension.

If it were someone I cared about, I would be more focused on the actual diving, since that is far more consequential with respect to safety.

 

[tursiops]

Hi @tursiops

For my AOW in 2004, I took Wreck, Navigation, Deep, PPB, and DPV. Where in the curriculum is the background to discuss gas management located? I have no manuals left from this time.

The manual for AOW, in the section on Deep, discusses gas management. Is is there in the manual copyright 2000, and is more extensive in the current manual.

 

[inquis]

An excerpt from the Deep section of the AOW e-learning:
As you know, the deeper you dive, the faster you use your gas. This calls for conservative gas planning on deep dives. Plan your turn pressure with adequate return, ascent, safety stop and reserve gas. [emphasis mine]

The emphasized terms are obviously constituents of Rock Bottom, and it seems reasonable that "reserve" would be those same things reserved for the buddy. They do go into surface consumption and extension to different depths, with the caution that "excitement, activity and cold all increase your breathing rate". Presumably, the instructor would elaborate on reasonable inflation factors.

For Imperial divers, they discuss a pressure-based consumption rather than a volume-based consumption, and caveat that you must determine consumption independently for different types of cylinders. For Metric divers, they have you multiply pressure usage by the cylinder volume, so the calculations will inherently be volume-based and therefore apply across varying cylinder sizes.

 

[tursiops]

do they reference the reserve pressure for both diver and buddy or just diver?

Not specifically in the material; it is up to the instructor.

just wondering and I can give this kid some pointers as he takes his PADI deep diver class.

This might not be a good idea; it might be best to wait until the class is over, so as not to confuse or induce doubt in the student's mind about the instructor's competence.

 

[jadairiii]

This might not be a good idea; it might be best to wait until the class is over, so as not to confuse or induce doubt in the student's mind about the instructor's competence.

So dont give him any of George Irvine's posts from Techdiver to read before he takes the class?

 

[tursiops]

So dont give him any of George Irvine's posts from Techdiver to read before he takes the class?

Before, during, or after!

 

[Josh the diver]

so I have access to the deep diver eLearning they say a good air management plan is using thirds to be conservative. its up to the instructor on what gas plan to use.

 

[Lorenzoid]

so I have access to the deep diver eLearning they say a good air management plan is using thirds to be conservative. its up to the instructor on what gas plan to use.

And in the classroom my instructor likely mentioned the rule of thirds as a "good" option, and we may have even gone through a calculation, and then we proceeded to do the dives without applying any of the rules we learned in the classroom portion. I recall the dives themselves more clearly than I can recall the classroom portion, and what made an impression on me was that after all the discussion about the various tools we could employ to mitigate the risks, we didn't really apply any of it to the actual dives. We ended the dives on approaching NDL. It really does appear to be up to the instructor how the dives are conducted.