More than "Advanced", but not really "Technical"

[Dive-aholic]

How can you guarantee that person has the gas to return if there is only one cylinder (read no redundancy)? I will not teach a decompression procedures class to someone in a single cylinder. That simply isn't the redundancy that is required for a dive in which a virtual overhead exists. I also don't believe a 19 cf pony will be enough in most cases. With an RMV of .6 at 100 FSW that 19 cf will be gone in 8 minutes. At 30 fpm ascent that will take 3 minutes, leaving only 5 minutes for stops. And that's if the RMV remains steady at .6.

 

[dumpsterDiver]

If you want to learn how to do emergency light deco on a single tank with no redundancy.... what is there to learn? Read the computer manual, practice stops, learn to manage your air consumption calculations... None of this requires any real training, just read the book... of course you do need to know how to do a safety stop.. and what value is the certification, if you plan on never using it except in an emergency.

Heck you can even do a "safe" simulation, use nitrox and punch in air and then put the computer into a little light deco... and have a back up computer running your actual mix of nitrox..

 

[DevonDiver]

PADI Tec40 provides 10min (non-accelerated) deco, with the option of >50% for conservatism only. For those seeking 'tecreational' diving (refined/advanced recreational approach for increased safety), rather than an entry to technical levels, the course can be completed using 'recreational' equipment, with either a H/Y valve or an adequate pony. The training stresses mindset, dive planning and gas management. Deco is not mandatory on the course (can be simulated). The course qualifies to 40m/130ft - i.e. recreational diving limit.

I concur with lowviz that training like this gives access to a wider breadth of skills, equipment and protocols that have distinct benefits for no-stop diving. Some might argue 'overkill', but others value the potential of making their dives more forgiving whenever/wherever they can. I also see merit in having the capability to apply conservatism through a technical approach to ascent profiling... along with the skills and equipment necessary to add a high level of assurance that your calculated profile can be completed exactly as planned.

I also see the 'trend' towards favoring more aggressive dive computers as a way of extending bottom time; especially for aggressive multi-day and repetitive diving. I guess some people are just more easily reassured by digits on a screen than others. It's more convenient to deal with those hypothetical numbers, than to consider real-world physiology, I guess.

"I can do XX bottom-time with this computer, but only XX bottom-time with that computer". It's ludicrous IMHO. Your body dictates what you can and cannot do without getting bent. Nothing changes in that reality, regardless of what is strapped on your wrist.

Applying a technical diving approach to aggressive recreational diving is nothing more than the application of prudent, conservative, common-sense. In reality, planning on a conservative model and doing mandatory stops, when you could otherwise plan aggressively with no mandatory stops, is nothing more than a slow ascent. Yes, you might choose to lengthen safety stops or slow ascent rates when diving aggressively. Doing that dive according to technical diving protocols is simply intelligent and precise ascent planning, rather than a 'fudge-factor' guesstimation... and, of course, implies a certain 'sincerity' in committing to that safe ascent. Plan your dive...and dive your plan. Accept that...and plan/prepare for... your planned ascent profile having a physiological impact that must be respected, rather than a hypothetical 'numbers of a screen' impact that can be ignored...

 

[Pullmyfinger]

TDI Deco Procedures is not the course you are looking for (Not sure what is unfortunately) Last dive on my Deco Procedures course was 150 feet for 30 minutes with 2 deco gases. Not the sort of thing I would choose to do with a single tank.........

The last dive during my Deco Procedures course was also a similar profile; with two deco gases.

I'm not sure what course will fit what Low Viz is looking for......a course that teaches enough about planned or accelerated decompression, but isn't geared for students to actually plan, or conduct those dives.

As Dumpster Diver mentioned; this might be a self study undertaking.

 

[DevonDiver]

I'm not sure what course will fit what Low Viz is looking for......a course that teaches enough about planned or accelerated decompression, but isn't geared for students to actually plan, or conduct those dives.

My interpretation was for a course that provided an improved skill-set and knowledgebase, derived from technical diving, that could be applied to recreational diving. At the same time, a course that did not mandate depths beyond 40m/130ft and/or extensive decompression obligation (i.e. "light" deco). 'Light deco 'was defined by the OP as 'no more than 10 minutes', but it was unclear whether this limitation was meant for back-gas deco, or whether it was an accelerated schedule, through use of deco nitrox. My assumption, given the intended purpose of use, would be non-accelerated deco.

It is, in essence, an illustration of a small trend towards the application of technical diving methodology to recreational diving. The purpose being to improve safety and conservatism.

As Dumpster Diver mentioned; this might be a self study undertaking.

I sometimes get the impression that Dumpster Diver, amongst others, view just about every sort of diving progression as a self-study undertaking.

The pros and cons of 'formal courses' versus 'mentoring' versus 'self-teaching' have been debated ad infinitum.

 

[lowviz]

How can you guarantee that person has the gas to return if there is only one cylinder (read no redundancy)? I will not teach a decompression procedures class to someone in a single cylinder. That simply isn't the redundancy that is required for a dive in which a virtual overhead exists. I also don't believe a 19 cf pony will be enough in most cases. ...//...

But that pulls the student into true tech. I most specifically do NOT want some divers to be given the tools for technical diving. I feel that it would be wise to offer the safety layer (borrowed from tech diving) to certain classes of divers. The physically unfit, PFO's, chronically inattentive, maybe even the very young and aggressive diver.

If you want to learn how to do emergency light deco on a single tank with no redundancy.... what is there to learn? ...//...

Easy for you or I, but the average vacation diver is lacking quite a bit of critical knowledge.

PADI Tec40 provides 10min (non-accelerated) deco, with the option of >50% for conservatism only. For those seeking 'tecreational' diving (refined/advanced recreational approach for increased safety), rather than an entry to technical levels, the course can be completed using 'recreational' equipment, with either a H/Y valve or an adequate pony. The training stresses mindset, dive planning and gas management. Deco is not mandatory on the course (can be simulated). The course qualifies to 40m/130ft - i.e. recreational diving limit.
...//...

It is, in essence, an illustration of a small trend towards the application of technical diving methodology to recreational diving. The purpose being to improve safety and conservatism.

Just wow. Yes, your post is precisely what I was trying to get into words. Beautiful piece of organization and writing.

I was not aware that PADI's Tech40 course had that focus. Thanks!

 

[tomfcrist]

The issue is that a holder of a TDI Deco Procedures Cert is expected to be competent in planning/executing a staged decompression dive to 150'. To do that dive without redundancy is stupid. One of the required skills for that course is to deal with a simulated valve/first stage hemmorage. How can you do that on a single tank when you have Deco obligation? Either a really big pony(80) or have doubles. Why an 80? Because you also need to have enough redundant gas to deal with total loss of deco gas as a contingency. The TDI deco course is NOT for the guy that wants to learn basic theory of decompression procedures, it is for the person that actually wants to dive with the intention of doing staged decompression. If you just want to learn the theory, take a NAUI Master Diver course, or something similar, where Decompression is simulated to give a student the BASIC understanding of what is required and the procedures to follow.

 

[victorzamora]

lowviz, PADI's Tec40 course is similar to what you're talking about. It "allows" up to 10 minutes of non-accelerated deco (but up to EAN50 for conservatism). I know Andy already said this, but what I wanted to add was that a good instructor for this course will teach all there is to know about planning simple, short, rec-depth dives with light deco. Your friend will learn enough to add conservatism while diving a single tank. The problem with expecting Deco Procedures to be done in a similar fashion is that Deco Procedures is a full-blown deco course whereas Tec40 is much more of a "gateway" course. It's much more simlar to Techreational diving, but allows a smidge of deco.

Another course to consider is GUE's Fundies. A course like that would prepare for the precision/skill of safety stops, provide a more stable platform for the diver, and provide some of the intro theory. I think that this might be a much more rewarding course because it's the beginning of diving like a tech diver, while Tec40 is more assuming you can already dive flat and stable. Also, the chances of finding a good GUE instructor are better than a good PADI instructor....and these classes ARE all about the instructor. However, what the card lets you do has to be taken into consideration....that's why so many people are against Deco Procedures being applied to this need.

---------- Post added January 6th, 2014 at 08:20 AM ----------

Actually: Has your friend considered Sidemount?

 

[ianr33]

Like I said, you need different course. Deco Procedures is about switching to a high )2 deco tank, not just doing a few minutes deco on backgas. Advanced Nitrox might be what you are after, but I'm not sure on that. (Most take Advanced Nitrox and Deco procedures together so it's hard to tell where one course starts and the other ends)

Why not do these courses and not dive to their limits? (Maybe you can borrow the gear?) If you know what you are doing, 20 minutes deco on backgas soon becomes pretty trivial.

 

[lowviz]

The issue is that a holder of a TDI Deco Procedures Cert is expected to be competent in planning/executing a staged decompression dive to 150'. ...//...

...//... The problem with expecting Deco Procedures to be done in a similar fashion is that Deco Procedures is a full-blown deco course ...//...

It is my understanding that the instructor can still tailor the course to two classes of divers, as shown in the OP. Things may have changed, but I believe that this is still true.

lowviz, PADI's Tec40 course is similar to what you're talking about. It "allows" up to 10 minutes of non-accelerated deco (but up to EAN50 for conservatism). I know Andy already said this, but what I wanted to add was that a good instructor for this course will teach all there is to know about planning simple, short, rec-depth dives with light deco. Your friend will learn enough to add conservatism while diving a single tank. ...//...

Yes, I now see that. Nice offering from PADI.

...//... Actually: Has your friend considered Sidemount?

I can't get into specifics, but extending downtime is not an option. It is all about safer ascents. I would much rather see her plan for and go into light deco on backgas than fudge her diveplan/computer to get a longer dive.