TDI Extended Range - last words of advice?

[DA Aquamaster]

Personally, I think the Extended Range course is not just valuable training but important to diver development. Just for clarification, we are talking about air dives to 180 feet.

I once knew a diver, and for the sake of this story let's call him "Bart". He was a deep air diver who anticipated his evolution into a Trimix Diver with unbridled enthusiasm. Bart had done any number of stupid things at stupid depths on air over many years. Now, with the magic of Trimix, he believed the era of doing stupid things was at an end!! No more mockery coming from peers! Praise Trimix!! Only accolades, victories, and artifacts lay ahead!! Onward!

Maybe not so much? On his very first Trimix dive, Bart did something incredibly stupid, just like he always did. Much to his total amazement, he still did stupid crap!!! What he did not know was that it was not the Nitrogen, it was him, and until he figured that out he was going to continue to do stupid things.

If breathing 30% helium is good, isn't 100% better? No amount of helium will make a dumb ass, smart. If you are "dumb as a stump" at 127 feet, this is god's way of telling you you need more experience before you go much deeper, or he wants to thin you from the herd. Helium for dives in recreational depths is not the answer for inexperience?

The bottom line is that there is no magic gas, no substitute for experience, and no shortcut to becoming a competent, capable deep diver. The only way to develop as a diver is by learning skills, challenging yourself, making dives, and gaining insight.

Trimix is a powerful tool, for use by craftsmen. Before you can utilize it properly and to its potential, you need to become a craftsman? Would you give a 4 year old a circular saw? You can't just show him the buttons and tell him to be careful?

I think the Extended Range program takes divers to reasonable depths for air diving and affords them the opportunity to gain valuable experience on air, before they move on to Advanced Trimix (if Trimix is what they want?).

Among the prerequisites for Advanced Trimix, which takes divers to 100 meters, the candidate needs to be either Extended Range or Basic Trimix certified, not both. In my opinion, the divers that come from Extended Range bring a higher degree of respect for the perils of the environment, and a greater level of skills, fully earned by their bottom time on air.


Cheers

JC

Well stated. And very funny.

I have argued the point in the past that while narcosis degrades your intellectual abilities, what a particular diver starts out with at 1 ATM makes a big difference in how that particular diver performs at depth on air - or as you basically put it, helium will not cure underlying dumbass tendencies.

In that regard I like the the TDI approach of going to 150' with Advanced Nitrox and Deco procedures followed by Extended Range where you can essentially add two helium dives at the end. It gives you deep air experience to 180' and the ability to contrast that with the similarities and differences you experience on trimix to 200'.

 

[DA Aquamaster]

Seatbelts, airbags, parachutes and ejection seats are all pretty much useless in a benign environment also. Unfortunately, we can't always control our environment. My personal view is that I make sure I am prepared and trained and use the proper equipment including gas mixture to deal with situations where my once benign now wants to help send a floral bouquet home to my wife. Your approach is no big deal as long as everything goes right; my approach is no big deal when everything goes wrong. When things go right for me, it just cost some more and took me more training to get to that point. When things go wrong for you, you are in deep sh-t.

I am not going to waste anymore time debating deep air. I never could talk some friends out of drinking and driving either. Lets just agree to disagree.

I agree with part of what you are saying but not all of it. Divers can to a greater extent than you suggest control their environment or at least recognize when the "oh ****" potential is there. Those may well be the dives you do not want to do on deep air. But on the other hand, I don't see the point in doing all dives below and END of 100' (or whatever other number a particular diver choose between 60' and 130') on helium just because the END is below X number of feet. On some dives, if the potential is not there to exceed you abilities while on air to deal with the situations and emergencies that may arise, there is not always a need for helium just because the END is below x feet.

For example, I used to wear a parachute 1) when strapping on a plane to do aerobatics, or 2) when climbing into my glider to go soaring. In the former the parachute was needed as the potential was greater to pull the wings off or other wise break the plane, in the latter a chute was primarily needed as the seat was designed for use with one and was not real comfortable without one. However, when hopping into a C-172 or Bonanza I did not wear a chute. Sure a parachute would be nice to have in the very unlikely event it was needed on those flights, but the probability of needing it was so remote that using one was not warranted - even on night single engine IFR flights.

So it is and should remain a personal decision and an extended range/basic trimix course is a good way to develop the ability to make an informed decision about your limits.

 

[Chatterton]

We have been talking about air dives with an instructor to 180', not 230', not 300', not 454'. If air were not a reasonable gas for divers to use at 180', then the technical diving agencies would not be offering training programs to that depth. If it were "crazy deep", then we would have bodies stacked like cord wood, and IANTD and TDI would have been sued out of existence long ago.

Any student for either Extended Range or Basic (Normoxic) Trimix, has to have a minimum of 100 logged dives, and be Advanced Nitrox and Deco Procedures certified. These students are not Novice divers, and are not diving to 80 feet one day, and 180 the next.

What causes narcosis? I suspect you just said, "nitrogen". Name a gas more narcotic than "nitrogen", I ask? You have it in your system right now, and when the concentrations increase, it produces a far more dangerous narcotic effect, and ...... well I can just go on and on, can't I? My wife says I never shut up.

I don't think those opposed to dive training on air to 180 feet really get it, and it is most likely because they don't have anything in the way of experience on air at that kind of depth. The terms they use to describe diving to such depths are more than a little overblown, because they have not really been there. If you would not venture to 180' on air, in a training environment, you probably should not be throwing a tank of helium in the garage either?

Anyway, watch out for CO2 as well. Far more narcotic. You probably don't want to embrace narcosis, but you might want to understand it a little bit especially if you want to be a deep diver? I would rather have my loved ones dive (to any depth) with an Extended Range diver, rather than a Basic Trimix diver. Sorry, but I think they have better training?

This is my opinion, and one size does not fit all. I guess that is why TDI offers both courses?


Cheers

JC

 

[brockbr]

I am not sure if you are making a joke with your comment or not, but if you are, then it is kind of funny. If not, I have to ask you if you see tech diving as an adrenaline sport? If you do, you might find your dive buddy selection process to be.....let's just say, less than enthusiastic.

It was a funny way of saying JC had experience = You know - That thing you get immediately after your needed it? (<- pssst - That's "humor" too )

(btw, the "can't get the stink out" comes from a shirt a friend has)

Adrenaline sport? Um, no. An attitude like that wold get me killed inside of a week with the kind of diving I do.

I'm not going to argue with you about deep air - We disagree, that's all.

 

[battles2a5]

I don't think those opposed to dive training on air to 180 feet really get it, and it is most likely because they don't have anything in the way of experience on air at that kind of depth.

Agreed, I would venture to say that 99% of the people on scuababoard that chastize deep air have never done it and have absolutely no context of what a moderate depth (180') dive on air feels like, especially in a warm and clear environment where workload, stress, and equipment are minimal.

Anyway, watch out for CO2 as well. Far more narcotic.

Bingo. I think CO2 is a much worse constributor to narcosis, especially at depth. CO2 will slam you at the worst possible time (when stress and work increase). At least inert gas narcosis is predictable and can be planned around. Bismark's comment about his approach (e.g. no deep air) being no big deal when things go wrong is highly dependent on the diver's ability to keep CO2 at bay. Inert gas narcosis is only part of it. I deep air diver that keeps his cool will likely fare better than an overconfident newb on He when the poop hits the fan.

Anyway, enough of this. Let's get back to encouraging Rhone Man on this upcoming class

 

[HowardE]

I did the Extended Range course with Uwe in the DR. It was great training, and I'd have to agree with everything JC is saying.

Especially about the part where his wife says he never shuts up.

 

[rjack321]

Ahhhh CO2
made physiologically during respiration, aka work
big contributor to increased work at depth?
nice thick air
So who doesn't get it again???

 

[Bismark]

If air were not a reasonable gas for divers to use at 180', then the technical diving agencies would not be offering training programs to that depth.

JC

I find this part pretty amusing. You might want to qualify your statement with "some technical diving agencies".

In the case of your comments about those criticizing deep air not having done it, you are incorrect in this case.

We have each chosen to interpret the available knowledge differently. Happens all the times between "experts" in every field. Nice thing about living in a free society.

It will be interesting to see what 10 more years of science and education come up with. I have my suspicions but time will tell.

 

[battles2a5]

Ahhhh CO2
made physiologically during respiration, aka work
big contributor to increased work at depth?
nice thick air
So who doesn't get it again???

How big of a contributor to CO@ production do you REALLY think WOB on open circuit is compared to:
- Stress
- Actual Work (e.g. intertia and drag from pushing heavy steel doubles and drysuit vs. AL80's and wet suit)

If somebody gets stressed and their breathing rate skyrockets, the WOB due to helium is not going to make a whole lot of difference. Pushing 70 more pounds of gear with a lot more drag is going to produce a lot more work than sucking air vs. mix. Of all the reasons to use helium, I think this argument is a weak one in the big scheme of things.

 

[Peter Guy]

DISCLAIMER -- I AM A TOTAL NOVICE AT ALL THIS! The following are merely comments from someone who has followed this thread and finds it interesting -- and no, I do not dive "deep air" (any more) nor am I (very) technically trained.

- - - - - - - - - - - - -

The various comments have reminded me of some things from my past which are:

a. Diving deep air in the late 60's in Maui and absolutely loving it. However, I've been told by someone who was with me that he and another fellow diver felt compelled to each grab an arm and "guide" me back up to about 100' and set me down on a ledge -- at which point I am alleged to have "come to" with a rather quizzical look on my face. In other words, I had a wonderful "warm narc" while I was looking for things in the greater than 140' range but was pretty well out of it.

b. Several years later, while working in "law enforcement" (prosecutor), I had the privilege of going through the bank of DUI physical tests after imbibing a "moderate amount" of alcohol at our office Christmas Party. This convinced me, as nothing else could have, that I had no idea how impaired I was after even a "moderate amount" to drink.

These two different experiences point out, to me, a couple of truths:

1. Narcosis hits people differently -- period, end of story.

2. Unless someone who is NOT under the influence is around you when you ARE under the influence, your ability to accurately gauge your own impairment is pretty limited.

I don't know if it is good, or not good, or somewhere in between, to teach people how to dive "deep air." I know from my one experience that having someone show me how impaired I was after moderate drinking was a real eye opener. (Note, I will NOT say whether it actually changed my habits!) But I think a very important part of that experience was that I was surrounded by sober people -- not other impaired people.

This leads me to ask my first question -- Are the "deep air" instructors on He mixes or are they also breathing air?

My second question for Rhone Man (or whomever) -- What is the purpose of learning to dive deep air? Is it to learn about how impaired one can become (as was my experience at the Christmas Party)? Or is it to learn how to dive deep air -- i.e., experience the inevitable narcosis so that you have an idea how to "deal with it."