Technical Diving Advice?

[nadwidny]

My point to the OP is that people have dived, and continue to dive, very deep using air, despite the very real increased risks. And that knowledge and training are available to people who want to dive this way.

Exactly. It's all about conditioning and getting used to it. I started to drive after just one beer. Then after I was ok with that I went to driving after 2 beers. After a lot of time and gaining knowledge I now drive after having a dozen and nothing bad has happened.

 

[Ulfhedinn]

Extended range diving to 1.2 to 1.4 Po2 depends on water temperature/workload/current and what gas mix is utilized. Air/Nitrox is a viable option in warm waters. I would use 20/25 in moderate temperatures with Po2 never exceeding 1.4. Rest assured if you go the CCR route, expect to pay $500 per dive for the first 40 dives, this includes: cost of CCR, gas, sorb, O2 cells annually, maintenance, training, and other miscellaneous costs. And you would need to dive the unit more than 20 times to be sufficient. Gas density isn't a big deal when using OC; it is a problem when using CCR however. Gas laws dictate the situation with OC.

If you hear an instructor answer: you will die, or you hear others saying: run. It means they don't have the answers to your questions.

I don't think your are suppose to post those PDFs for free? I might be wrong.

 

[Heat Miser]

So my question is, used or new rebreather? Where to buy? What is the cost per dive for you using your rebreathers on Trimix? Any other advice would be greatly beneficial! Thanks!

I saw a lot of posts saying do intro to tech, do AN/DP, do doubles. before CCR ..... Maybe ..... but you don't have to ... these days there alot of Air Dil no deco courses that can get you started on a CCR.

I would say its largely about how good your buoyancy is to start with, and secondly whether you have CCR buddies to practice with once certified.

Secondhand is OK if its a popular unit that you have a good instructor for and you will have buddies diving the same unit.

 

[broncobowsher]

Air Dil CCR is fine. but you really need the AN to get the CCR to really be usable. Since AN is paired so nicely with DP, might as well get that out of the way. Get the basics taken care of on OC. So a switch to CCR will only be climbing mt. McKinley instead of mt. Everest.

I spent the first year of my CCR with air Dil. There is enough learning curve that I felt it was the correct thing to do. I did a whole lot of recreational dives on CCR. Even that is fun. First in, last out, just chill and watch the bubbles from everyone else. The clock isn't ticking away like OC recreational dives. After a year I was feeling competent, got back with the instructor, and took the next step. 200' is plenty for now. I know there is deeper. I am not ready. So much to see in that 100-200' range. Deco is tolerable.

Get the AN/DP out of the way so when you actually take the CCR class, you are learning the CCR. Not trying to learn AN at the same time. A good instructor teaching AN/DP, knowing that you will be going CCR, can lean the course a little in that direction for you.

Now the value of Helium during the AN/DP? That is a bit of a toss up. I'm not opposed, but I don't see it as a must have either. You will learn it in MOD2 CCR class.

 

[Marie13]

Now the value of Helium during the AN/DP? That is a bit of a toss up. I'm not opposed, but I don't see it as a must have either. You will learn it in MOD2 CCR class.

It all depends on how bad you get narced. For me, OC Helitrox was a no brainer. Other people, maybe not so much.

 

[Heat Miser]

Air Dil CCR is fine. but you really need the AN to get the CCR to really be usable. Since AN is paired so nicely with DP, might as well get that out of the way. Get the basics taken care of on OC. So a switch to CCR will only be climbing mt. McKinley instead of mt. Everest.

I went straight from Air/Dil no deco to CCR Helitrox, without AN/DP, I went back and filled it in later. I had nothing else to do ... I live in Western Australia, so it was the last place in the world to open back up after COVID and I couldn't travel to Victoria, to do MOD 2. I'm not certain I needed to fill it in, I don't regret doing AN/DP but I'm not certain it was necessary to dive the rEvo.

 

[DiveTucson]

This thread is full of some fantastic advice and some absolute trash advice. What makes this more interesting is that as possible new tech diver the OP has no idea which is which. Getting your advice from this thread could end up on both sides of the spectrum.

Look for an instructor that is doing the type of diving that you want to be doing and have a conversation with them. I would caution taking any advice from this thread as you won't know what is good or bad...

 

[Lorenzoid]

Look for an instructor that is doing the type of diving that you want to be doing and have a conversation with them.

The OP says he's signed up to take TDI's AN/DP. I do agree that a good place to start with questions about rebreathers and such goals that may be years down the road would be that instructor or maybe another instructor. The OP should consider getting through the AN/DP course, getting to know people who are doing the type of diving he wants to do, and starting the conversation with them about the longer-term goals and the tools they recommend.

 

[wetb4igetinthewater]

I remember a while back when TDI change Mod1 air dil from a 45m cert to a 40m cert

I can't speak for the past, but last August I took this course. It is to 30 meters. TDI Air Diluent CCR Diver Course - International Training - SDI | TDI | ERDI | PFI, from: https://www.tdisdi.com/wp-content/u...r Standards_30_AD_CCR_Unit_Specific_Diver.pdf

30.2 Qualifications of Graduates
Upon successful completion of this course, graduates may:
1. Engage in diving activities utilizing the CCR to a maximum depth of 30 metres / 100 feet, utilizing air as a diluent

 

[Heat Miser]

I can't speak for the past, but last August I took this course. It is to 30 meters. TDI Air Diluent CCR Diver Course - International Training - SDI | TDI | ERDI | PFI, from: https://www.tdisdi.com/wp-content/uploads/files/sandp/currentYear/TDI/part 2/pdf/individual/TDI Diver Standards_30_AD_CCR_Unit_Specific_Diver.pdf

30.2 Qualifications of Graduates
Upon successful completion of this course, graduates may:
1. Engage in diving activities utilizing the CCR to a maximum depth of 30 metres / 100 feet, utilizing air as a diluent

Correct,

You can do alot of self damage between 0 and 100 feet, learning how to dive a rebreather. Relearning how to manage buoyancy, managing loop volume, drysuit and wing. How to bail out, when to bail out, How to maintain and service your rebreather, build your rebreather, manage bail-out cylinders, there's alot of new stuff going on. It was very rare I went into any real deco on my first 50 rebreather dives and some of them went for 2 1/2 hours.

The biggest bit of misinformation given to me was that I had to get a tech pass in order to progress to OC deco in order to progress to CCR.

I was talking to guy on boat (he was showing me his poseidon) and I said I would like to try diving rebreathers but I need to get better trim and buoyancy skills before hand. He just looked at me said don't worry about it just get into it, if that what you want to be doing, but don't buy a rEvo. (He now dives JJ and I did buy a rEvo). I think he was right when it comes to rebreathers, there is a bit of unlearning to be done from OC.