What can I learn from PADI Tec 40 course?

[Colliam7]

The "clear-headedness" aspect is not just only for better appreciation of the aesthetics of the dive (i.g. Marine Life; coral colors etc), but more importantly to deal with emergency contingencies at depth.

I fully appreciate that this is part of it. I have also, during these dives, attempted to add a cognitive component - doing math problems, since that is one thing we do in other training to assess possible effects of narcosis. A diver (me, in this case) is given a slate at depth with two multiplication problems, a) two, 2-digit numbers (e.g. 34 x 67), and b) two, 3-digit numbers (e.g. 671 X 456) and the time required to compute the answer is measured (in seconds), and the accuracy verified. There was no discernible / meaningful difference in time required, or accuracy - under the two conditions (air vs. trimix). The time required for a 3-digit problem was substantially longer - not proportionally, which appeared to be the case on the surface, but even longer with either mix.

The issue I have with my own experience, and as a matter of full disclosure - this is an N-of-1 experience. I can't say it applies to anyone / everyone. BUT, I can say it is my, somewhat objective, experience.

In my opinion it is better to learn and practice these vital skills (valve shutdowns; out-of-gas scenarios; primary light failure etc) early and often with Trimix & cognitive clarity, before electively choosing to deal with the potential handicap of narcosis on Deep Air --especially if going into further or future training in deep overheads such as a wreck or cave. . .

A fair opinion, and with this one I will specifically disagree. I am unaware of any evidence supporting the value of a particular sequence. If such evidence exists, I would like to be made aware of it, because that would change my view. HOWEVER, I can fully nonetheless respect the thoughtfulness and sincerity of the opinion. And, I readily acknowledge that my own opinion is also just that - my opinion.

 

[Kevrumbo]

It's not only being able to perform single rote tasks like simple arithmetic of the above, but also applying those tasks to complex problem solving for a particular scenario while under the influence of deep air narcosis (example of performing the arithmetic/algebra on-the-fly for a Lost Buddy Search on remaining bottom gas and executing the plan under stress).

To use a gross analogy, the PADI Tec40 initial deep air progression would be like taking an advanced Driver"s Education or even a Racing Class by first drinking a couple cans of beer before getting in the car, and then learning how to accommodate to the cognitive impairment while driving/operating the car around the road course. . .

 

[DevonDiver]

I do find it amusing how certain agencies, and personalities, have managed to 'normalize' the term 'deep air' to mean anything below 30m/100ft.

It seems we have a regression of about 10m per annum (1m per year) in that definition. By extrapolating from that linear trend, it'll only be another 2 decades before certain people will be arguing against the lunacy of Discover Scuba Diving excursions without helium.

For diving in the parameters discussed in this thread (Tec40 - 'lite' deco in recreational depth limits) the concept of trimix is on a par with gold-plated iPhones and $10,000 mattresses. It's just an ego boost for those with something to prove and money to burn.

 

[Kevrumbo]

I do find it amusing how certain agencies, and personalities, have managed to 'normalize' the term 'deep air' to mean anything below 30m/100ft.

It seems we have a regression of about 10m per annum (1m per year) in that definition. By extrapolating from that linear trend, it'll only be another 2 decades before certain people will be arguing against the lunacy of Discover Scuba Diving excursions without helium.

For diving in the parameters discussed in this thread (Tec40 - 'lite' deco in recreational depth limits) the concept of trimix is on a par with gold-plated iPhones and $10,000 mattresses. It's just an ego boost for those with something to prove and money to burn.

Rhetorical scatology & non sequitur . . .WTF are you talking about?

 

[DevonDiver]

Rhetorical scatology & non sequitur . . .WTF are you talking about?

1) The nonsensical assertion that Tec40 is in any way, shape or form a 'deep air' course.

2) The re-definition that 'deep air' is any depth above which an argument for helium is utterly absurd.

3) The concept that educating the use of helium should prioritize above basic, fundamental skills and procedures at the most basic entry-level of tech.

4) The notion that narcosis is debilitating, to the extent of significantly impacting safety, for open-water divers in the 30-40m range.

 

[Kevrumbo]

1) The nonsensical assertion that Tec40 is in any way, shape or form a 'deep air' course.

2) The re-definition that 'deep air' is any depth above which an argument for helium is utterly absurd.

3) The concept that educating the use of helium should prioritize above basic, fundamental skills and procedures at the most basic entry-level of tech.

4) The notion that narcosis is debilitating, to the extent of significantly impacting safety, for open-water divers in the 30-40m range.

A bottom mix which maximizes the highest possible fraction of N2 and thereby the largest potential PPN2 ongassing gradient with an increased Work-of-Breathing effort at the 30 -40m range can only be deduced as "Deep Air". So you potentially have real & serious issues of CO2 retention & narcosis due to increased work of breathing upon hard physical exertion, as well as loading up & satrurating your slow tissues with high PPN2, and finally limting a cleaner more efficient decompression by only using EANx50 for deco. For the newly PADI Tec 40 Certification Graduate, two dives a day on such a profile over several consecutive days would be risking a type one DCS event.

All of which can be mitigated in the first place for the beginning Tech Diver -in my honest opinion- by using a proper Triox or Trimix bottom gas along with both 50% & 100% Oxygen deco gases. . .

 

[steady1570]

I have about 10 different spec and a PADI Master Diver. Looking to learn more about Deco and Dbl's. Not looking to get deep into Tech but just some simple basics. Is the the right course for me?

My first foray into tec diving was when my local group of divers invited me on an “extended range” liveaboard. At the time I was in a similar position to you with no tec experience but perhaps more than a passing interest in going down that route and going on the trip. Due to the local instructor (un)availability, I was pretty much limited to the Tec40 course rather than some of the others being mentioned in this thread, but I am comfortable in saying that it was absolutely worthwhile. Again, it is mainly down to the instructor (I had a good one) as to what exactly they teach / emphasise but I found the most important takeaway was the change in mindset that you have to have to dive with a virtual overhead. Looking back, I see the Tec40 course as a “try before you buy” step – it allowed me to discuss the approach needed for diving beyond NDLs and more importantly to practice some of these skills in the water. Precisely because the course is limited in scope (40m, <50% deco gas, 10mins non-accelerated deco etc) I found that I could focus more on whether I wanted / could do this type of diving and what it would entail generally (much better situational awareness, strict adherence to runtimes, complete comfort in the water, the list goes on) rather than worrying about mastering all the different drills that you need to dive “deep and long”.

After completing the course I decided that tec diving was for me, and pursued it through Tec50 (and now onto CCR). I followed the PADI route this time because I wanted to remain with my instructor - good ones can be hard to find! Would I say that I was ready to Tec dive after the Tec40 course? Probably not, as it really is just an introduction course in my mind. Did it prepare me for the further steps in technical diving? Absolutely. I wouldn’t necessarily say that the PADI tec courses are the best route if you are 100% certain that you want to pursue technical diving; I’ll leave others with more experience to comment on the merits of deep(ish) air, TMx etc, but if it is something you might be interested in, then it really is a good start that won’t break the bank.

Tec diving isn’t for everyone – it’s expensive, time consuming and can take up a lot of space in your home to name but a few things (as well as being an absolutely fantastic experience!), but I think the skills you get from these “intro to tec” courses are invaluable in all your diving, even if all it teaches you is to think a little bit about how much gas you are going to use before you jump in.

Mark

 

[Freezerbrn]

I have about 10 different spec and a PADI Master Diver. Looking to learn more about Deco and Dbl's. Not looking to get deep into Tech but just some simple basics. Is the the right course for me?

I can't believe i read all 7 pages Ugh!!! OP find a few agencies that offer intro tech style diving and read the course material on their website. Pick the one that best matches what you're looking for out of diving. I was in the same boat so to speak. The more knowledge you have the better choice you'll make for yourself. Yes it's really that simple.

 

[DevonDiver]

A bottom mix which maximizes the highest possible fraction of N2 and thereby the largest potential PPN2 ongassing gradient with an increased Work-of-Breathing effort ...

So my prediction comes true already? A DSD on air could be defined as 'Deep Air'?

So you potentially have real & serious issues of CO2 retention & narcosis due to increased work of breathing upon hard physical exertion, as well as loading up & satrurating your slow tissues with high PPN2, and finally limting a cleaner more efficient decompression by only using EANx50 for deco.

You're insane.. Too many chemicals in your kool aid.

Quote me one tangible, statistical shred of evidence that open-water air diving in the 30-40m range has any significant, measurable increased risk. If you quit regurgitating your agencies profit-mongering BS dogma for a second and though about it... sigh

For the newly PADI Tec 40 Certification Graduate, two dives a day on such a profile over several consecutive days would be risking a type one DCS event.

One-sided clap-trap. Entry-level tech...still learning the ropes, refining buoyancy, practicing run-times...and you want to load people with helium and claim it's safer from a DCS perspective than AIR? Give me a break....

Stop lying... yes, lying. You know the reality... your presentation is so twisted that, given you qualification, it could only be interpreted as a deliberate untruth.

All of which can be mitigated in the first place for the beginning Tech Diver -in my honest opinion- by using a proper Triox or Trimix bottom gas along with both 50% & 100% Oxygen deco gases. . .

I'm still waiting for you to tell us about Truk...

 

[Teller]

Andy,
I am interested in how you consider adding helium too much at the entry level? Is adding Nitrox to an OW course too much? I dont consider it much more myself. I understand your definition of deep air is different then mine but some people are effected by narcosis at relatively shallow depths. What would you suggest a person like that do?