When does PADI teach gas planning?

[Hoyden]

PADI/DSAT covers gas mangement in a comprehensive manner in their tec classes. It is covered more clearly in the DSAT materials than in the TDI and IANTD books for the same level classes. This material was fully and clearly explained in my Tec 1 and Tec Deep classes. I had an excellent instructor - and would have taken a tech class from him regardless of what agency certification he offered - he also teaches TDI/IANTD classes. My preference for the DSAT class came from looking at the training materials and discussing the training standards.

We covered gas management in every PADI class I have taken (from several diffent instructors through 3 different shops) - it was even covered a little in rescue.

Clearly YMMV,

Jackie

 

[Dive-aholic]

Odd. Just finished PADI AOW and deep. SAC rates are covered, including estimating your SAC from your dive history. We covered rudimentary gas planning in OW - nothing formal, but we set turnaround pressures based on there and back + 500 reserve. I don't have my deep or OW book handy, but check pp. 83-84 of AOW manual for the (very brief) discussion...

SAC rate is not all there is to gas management. You have to calculate tank capacity, rmv, tank size differences, etc. I read the DSAT manual a while back. I think they did cover gas management. DSAT does produce some of the best manuals available; however, their standards are not the safest. For example, when doing the deep air dive, the instructor must also be on air. It's not an option to dive anything else. Not very safe IMO. Having to manage 2-3 students at 165 feet while you're narced is not the brightest thing to do, but it's required by DSAT. That's why I'm TDI trained. And it is the instructor. The TDI manuals aren't great, but at least they're safe.

 

[MikeFerrara]

SAC rate is not all there is to gas management. You have to calculate tank capacity, rmv, tank size differences, etc. I read the DSAT manual a while back. I think they did cover gas management. DSAT does produce some of the best manuals available; however, their standards are not the safest. For example, when doing the deep air dive, the instructor must also be on air. It's not an option to dive anything else. Not very safe IMO. Having to manage 2-3 students at 165 feet while you're narced is not the brightest thing to do, but it's required by DSAT. That's why I'm TDI trained. And it is the instructor. The TDI manuals aren't great, but at least they're safe.

The bottom line is that being able to calculate SAC doesn't help you decide when to turn a dive.

 

[Jason B]

If you are making an ascent straight to the surface as opposed to making a multilevel dive with varying depths, the rule of halves is not a bad rule, but he should have explained to you what he intended and how he decided to use it over the rule of thirds, which is what your rock bottom figure is.

Rock bottom and thirds are not the same thing.

 

[scuba.ie]

I've gone from beginner up with PADI, and was never taught SAC or RMVs. However, I did a TDI course recently and the Instructor was using a DSAT gas planning table to calculate our required volumes, as its much better than TDIs (he said).
If I'm teaching a Deep speciality, or Rescue and above I include gas planning, as I feel that its something the student and their buddy need to be aware of.

 

[MikeFerrara]

PADI/DSAT covers gas mangement in a comprehensive manner in their tec classes. It is covered more clearly in the DSAT materials than in the TDI and IANTD books for the same level classes.

I guess "clear" is a somewhat subjective term. The IANTD "Technical Diver Encyclopedia" gives a complete treatment of gas management although I disagree with the method presented for gas matching because it's based on RMV. While ascent gas needs must take RMV into consideration the turn point relative to useable gas is strioctly based on volume...you turn when you hit a predetermined volume or pressure. Calculations based on RMV can certainly aid in estimating how long that will take but that doesn't effect the decission to turn or not.

However, I also disagree with the gas matching method presented in the DSAT material. Though it's based on volume they do it backwards from what is taught by the NSS and the NACD. Either will work but why go out of your way to do it different when some one else was there first? Generally, the diver with the larger gas supply lmits himself to using the same amount of gas that the diver with the smaller supply has as useable. As I recall, DSAT teaches that the diver with the smaller supply should reserve an amout equal to the useable amount in the larger supply. That means that if I carry a large enough supply, you couldn't dive at all, LOL.

My preference for the DSAT class came from looking at the training materials and discussing the training standards.

My dislike for the DSAT tech course is based on several points. And yes, as I recall, I paid about $200 for the complete student kit and the instructor kit so that I could review it. While some aspects may have been changed these are a few of the things that I don't like.

Instructor requirements
Approach to team diving
The specific way certain skills are taught...lift bad deployment for example.
Approach to equipment configuration.
The heavy emphisis on computer use.
The requirement to do "deep air" prior to trimix. Of course when they first introduced the program, there was no DSAT trimix course.

We covered gas management in every PADI class I have taken (from several diffent instructors through 3 different shops) - it was even covered a little in rescue.

Clearly YMMV,

Jackie

While your instructor may have covered gas management, it isn't a required part of those courses. Real gas management isn't even taught in the DM or instructor level PADI courses so there's no way to be certain that you even have an instructor who knows it.

 

[LG Diver]

Hi all,

Thank you for your great responses. To touch on a couple of points:

1) why were we trying to do the dive on Al 80's? Because that's all we could get our hands on, unfortunately. We tried several shops in the area, and the ones that have rental 100's were all out of them at the time. 80's are definitely not optimal, but even with a 2100 PSI rock bottom reserve they would still give 9 minutes at 130' at a normal SAC rate which is very close to the no deco limit.

2) I definitely agree that the #1 lesson from that day is that if I'm not comfortable with any aspect of the dive I'll opt out. The added "peer pressure" of being in class dives and being with a DM and an instructor should not have prevented me from speaking up more loudly and ultimately opting out if I still felt uncomfortable.

3) Ed, your calcs are exactly what I came up with, but I added 1 minute at depth (10 cu ft) and a 300 PSI reserve since we would likely have to be on our regs for the rough surf exit. This is how I got to 2100 PSI. Is it possible to deal with an emergency with less than this by skipping the safety stop, ascending at a faster rate, etc? Sure- but why would you want to plan for this?

4) Had my instructor's reply been "no, your calcs are off, we'll talk more about this later, but for now go with 1500 PSI" I could live with this. After all, I'm a pretty new diver and all I know about rock bottom is what I've learned from a bunch of strangers on the internet (though I love you all dearly The response that we wouldn't have acceptable bottom time if we planned for an adequate reserve is what really alarmed me from that discussion, and brought into question whether he even knows how to do gas planning. Perhaps I misunderstood him or he didn't mean to phrase it that way, but I will address this with him before continuing with any additional training with him.

Thanks again,
John

 

[Scuba_Steve]

I guess "clear" is a somewhat subjective term. .......

lol

My dislike for the DSAT tech course is based on several points.......

The specific way certain skills are taught...lift bad deployment for example.

What?

I take it you don't consider having your buddy hold you down or hanging your leg around the wreck good form when deploying a bag?

LOL

The video is too hilarious. What a complete joke.

While your instructor may have covered gas management, it isn't a required part of those courses. Real gas management isn't even taught in the DM or instructor level PADI courses so there's no way to be certain that you even have an instructor who knows it.

Without a doubt about it brother. And that's the bottom line as per standards.

 

[Web Monkey]

that nowhere in any of the above-mentioned courses does PADI teach gas planning.

You must have missed it.

It's right in the OW manual. "Be back on the surface with 500PSI".

It's right next to the instructions for russian-roulette: "Stop pulling the trigger right before the gun is about to fire"

Terry

 

[TSandM]

LG Diver, I had the exactly same experience as you did! I did the deep dives with my OW instructor, and startled him immensely when I offered the rock bottom calculation for a 120 foot dive on an AL 80 (which is darned near HALF the tank -- something which ought to give people pause).

One of the things that bothered me greatly at the end of OW was that I had been taught again and again to "plan my dive, and dive my plan", but I had very little idea of how to plan a dive! Specialty after specialty, and that didn't change.

Fundies . . . Can I also recommend Fundies? A class that teaches dive planning, gas management skills, and the team skills to cope with things when your plan goes out the window?