trimix training

[Adobo]

My take is how is how much helium do you need, how will you know if you haven't done a few deep air dives. What is acceptable end for me with he? 160 is my deepest on air, i remember every detail of my most recent. At least i have some perspective of my own personal end limits other than someone telling me. If your instructor is comfortable with you on air, and he dives air on a regular basis, why not learn under supervision?

What if you figured out that you have reached your own limits with air long before 160ft? Like say at 110 ft? Should you still continue going progressively deeper with air? All the way to 200ft? For what purpose?

add if you do the deep air, and are narced, why cant you signal to ascend to a shallower depth and finish your runtime? Getting narced isn't instant death. Oh i'm narced, lets ascend.... Noone has ever said no. You stay here.

What about the other way... what if you have to ascend on a very specific spot (the anchor line). At your furthest distance from the anchor, you or your buddy experiences a problem. You have to debug the issue and make decisions on the next course of action. Your breathing rate and your heart rate are increasing (as is CO2 loading).

Is your experience of diving deep air under the supervision of an instructor under benign conditions equivalent to what you are experiencing now? If not, is it possible that the conclusion you walked away with from your deep air experience in class gave you a false sense of abilities?

---------- Post added July 22nd, 2013 at 04:27 PM ----------

Maybe your team skills are so good, and your site selection and dive planning decisions are so exacting and risk-adverse that you yourself could never wind up OOG a ways from where you need to ascend, without one of your He-loving buddies in sight.

So, several things have to converge for this to happen.
- First, one gets separated from his buddy (and continues the dive long enough that...)
- Second, one then runs out of gas either due to another unfortunate mishap or just as a natural result of extending the dive as an inadvertent solo diver and going beyond one's gas limits. The former being two major failures in one dive, the latter being self inflicted due to stupidity.
- Third, another diver/team happens to be within the vicinity. This other diver is diving air as opposed to trimix.

Even though this scenario seems incredibly unlikely, let's for the sake of discussion say it does happen. How is deep air experience from a trimix class of benefit? If I am out of gas and the only gas that is available is air, I am going to take the donation and breathe air. Irrespective of whether or not I have any deep air experience. And unless a diver has any recent experience acclimating to deep air diving (which in itself is debatable as far as improving one's functional abilities diving deep air), the diver is going to be just as narc'd either way.

So again, what is the benefit of mandating deep air as part of a trimix class?

Like I said, how you dive is not my concern. I just don't get people who obsess over a 'proper previous planning preventing piss-poor performance' approach to diving, but avoid with evangelical zeal the gaining of any experience with air below whatever (ever-climbing) ideal depth they've been told is unsafe without He.

How anybody dives outside of your community is not your concern. And yet, here you are posting in this thread anyway. Why? If you are interested to share/gain knowledge, then isn't it valid for people to challenge your points? Are people just supposed to take your word as gospel?

 

[syntaxerrorsix]

Some people get narced in the bathtub apparently. A man's gotta know his limitations...

The "I won't take AN/DP before trimix" comment really goes to show that some folks are probably just not comfortable enough with diving to be at that depth.

Just my opinion.

 

[Dr. Lecter]

The "I won't take AN/DP before trimix" comment really goes to show that some folks are probably just not comfortable enough with diving to be at that depth.

To some, helium is a tool; to others, it seems to be a crutch.

 

[tkdgodess]

my answers for you below..

What if you figured out that you have reached your own limits with air long before 160ft? Like say at 110 ft? Should you still continue going progressively deeper with air? All the way to 200ft? For what purpose?
Only you know your limits. Thats a good thing. Too bad for you its 110.


What about the other way... what if you have to ascend on a very specific spot (the anchor line). At your furthest distance from the anchor, you or your buddy experiences a problem. You have to debug the issue and make decisions on the next course of action. Your breathing rate and your heart rate are increasing (as is CO2 loading).

Is your experience of diving deep air under the supervision of an instructor under benign conditions equivalent to what you are experiencing now? If not, is it possible that the conclusion you walked away with from your deep air experience in class gave you a false sense of abilities? No. I learned my personal limits, plus the 15 year recreational base on air to 130, i know when its a good idea for me to use trimix. 180 mid channel wreck dive. Trimix yes please. Need to find the line.... Its dark when you dive deep in canada. Mid channel no reference ascents are challenging but doable, have the line you are relaxing...

---------- Post added July 22nd, 2013 at 04:27 PM ----------



So, several things have to converge for this to happen.
- First, one gets separated from his buddy (and continues the dive long enough that...)
- Second, one then runs out of gas either due to another unfortunate mishap or just as a natural result of extending the dive as an inadvertent solo diver and going beyond one's gas limits. The former being two major failures in one dive, the latter being self inflicted due to stupidity.
- Third, another diver/team happens to be within the vicinity. This other diver is diving air as opposed to trimix.

Even though this scenario seems incredibly unlikely, let's for the sake of discussion say it does happen. How is deep air experience from a trimix class of benefit? If I am out of gas and the only gas that is available is air, I am going to take the donation and breathe air. Irrespective of whether or not I have any deep air experience. And unless a diver has any recent experience acclimating to deep air diving (which in itself is debatable as far as improving one's functional abilities diving deep air), the diver is going to be just as narc'd either way.

So again, what is the benefit of mandating deep air as part of a trimix class?



How anybody dives outside of your community is not your concern. And yet, here you are posting in this thread anyway. Why? If you are interested to share/gain knowledge, then isn't it valid for people to challenge your points? Are people just supposed to take your word as gospel?

 

[Scared Silly]

I should train on deep air just in case I am ever diving 18/45 at 200', get separated from my team, have a catastrophic failure losing all of my back gas, and run into a deep air diver deep inside a wreck with immediate ascent to a deco stop not an option.

Hopefully the air you get from the deep air diver at 200' will be alive:

Fatal Diving Accident Caught on Tape - YouTube

I hate taking air from a dead diver

 

[HIGHwing]

To some, helium is a tool; to others, it seems to be a crutch.

To some Helium is a strategy.

 

[Adobo]

my answers for you below..

Thanks but your answers did not speak to the important parts of my questions.

Remember, the original posters question..

So I was roaming around the internet the other day, bored, and came acrossed a website advert for normoxic trimix training. The description of the course is what got me thinking. It stated that after skills and drills they would be doing several deep air dives in the 180fsw range prior to conducting the trimix dives. The description went on to say that there were valuble lessons to be learned on these deep air dives.

I found this to be very curious. I do not dive deep air. People do. What was the lesson to be learned? I do not see the value in deep air as part of a mix class. Your threshhold for narcosis should have been addressed in a much earlier class, or during adv/nitrox-deco proc. what say you?

If I already know my limit for diving nitrox, be it 110ft or 150ft, or whatever, what is the point of including deep air as part of a trimix class?

---------- Post added July 22nd, 2013 at 07:35 PM ----------

To some, helium is a tool; to others, it seems to be a crutch.

Why don't we try this another way..

Let's say you had someone who is interested in taking trimix training while in Oahu and they contacted Kaimana Divers for a class. One thing that they tell you is that they already know that the gas density of nitrox plus nitrogen narcosis becomes a factor for them between 100 and 130ft. And they they have no interest in doing deep air dives as part of the class.

Would you:

a) Convince them that there is a benefit for doing deep air dives to 180ft as part of the class? If so, what are those benefits?
b) Tell them that, "To some, helium is a tool; to others, it seems to be a crutch."?
c) Allow them to take the trimix class and exclude the deep air dives from the class? If so, why?

 

[Dr. Lecter]

Why don't we try this another way..

Let's say you had someone who is interested in taking trimix training while in Oahu and they contacted Kaimana Divers for a class. One thing that they tell you is that they already know that the gas density of nitrox plus nitrogen narcosis becomes a factor for them between 100 and 130ft. And they they have no interest in doing deep air dives as part of the class.

Would you:

a) Convince them that there is a benefit for doing deep air dives to 180ft as part of the class? If so, what are those benefits?
b) Tell them that, "To some, helium is a tool; to others, it seems to be a crutch."?
c) Allow them to take the trimix class and exclude the deep air dives from the class? If so, why?

You'd need to take that up with Kaimana's tech instructor; while I enjoy diving with KD, I don't work for them (or anyone else in the diving world). I know his agency is PSAI, which looks like it requires at least AN (air to 150') for Trimix Level 1 (may require Extended Range Nitrox (air to 180') and encourages/makes optional Narcosis Management Level V (air to 200') in connection with Trimix 1... so I'd guess he'd at least want to see some experience in the realm of what you'd call deep air. Whether it's part of the Trimix Level I course itself, I don't know.

Were I an instructor (not that there's enough money in the world to make me sully the enjoyment I get out of diving by having to be responsible for students while doing it) looking at taking on a student for diving at those depths and my affiliated agency allowed (if not mandated) it, yes, I would insist on demonstrated experience with air at such depths or a willingness to do such a dive as part of the course.

If you want someone to teach you Trimix without any deep air experience/dives as part of/prerequisite to the course, go elsewhere. If you have a hard time finding such an intructor...maybe that should tell you something.

 

[nimoh]

It's just amusing to me that I'm getting a 'that's just an unrealistic scenario' lecture from someone with an "Always plan for the rare things" quote in their profile, when the scenario I'm positing can and has happened to tech divers since before tech diving was a thing.

Maybe your team skills are so good, and your site selection and dive planning decisions are so exacting and risk-adverse that you yourself could never wind up OOG a ways from where you need to ascend, without one of your He-loving buddies in sight. Maybe you'd never conduct a penetration that required you to stage deco gas outside the wreck, which is a great way to find yourself needing to do navigation at the bottom before you get to just ascend. Maybe doing a few dives in the 150'-200' range on air would kill you rather than providing some useful perspective and another experiential tool in the toolbox.

Like I said, how you dive is not my concern. I just don't get people who obsess over a 'proper previous planning preventing piss-poor performance' approach to diving, but avoid with evangelical zeal the gaining of any experience with air below whatever (ever-climbing) ideal depth they've been told is unsafe without He.

My point is that this scenario is beyond rare, and I am having a hard time believing that it happened as described.

However, my team skills and those of the divers that I would do such a dive with are that good.

 

[rongoodman]

If you want someone to teach you Trimix without any deep air experience/dives as part of/prerequisite to the course, go elsewhere. If you have a hard time finding such an intructor...maybe that should tell you something.

Deep air isn't required for either TDI or IANTD Normoxic courses, and instructors who follow the standard aren't hard to find.