DIR- Generic Tdi Normoxic trimix or CCR?

[Adobo]

Oh absolutely it is a regression of service. For the expeditions we have planned, we have to carry some extra cylinders with our DIL (and O2) that we use transfer whips from 15 L cylinders to our 3L cylinder CCR bottles. We won't have perfect fills with topping off, but good enough for most dives. For the 100 meter plus dives, we do have a dive center that supports trimix/rebreather dives (Kos).

No, your question is one for clarification. If the helium supply continues to dwindle, I'd expect more shops to supply only rebreather divers. They may provide fills for a larger tank that is used to top off. I don't know what's going to happen. If the current trend continues, there will be business changes.


Oh, I've got it figured out. Most will just drop out.

Well, a lot of equipment manufacturers don't see it that way. Want to pay more for gear? That's going to be part of it. Prices are affected by volume.

And if the technical diving market shrinks to that if the mid 90s, it isn't an issue for me personally. I don't ever plan on teaching tech, and I'll be getting my own helium. But I'm looking at the bigger pictures. Maybe GUE will shrink back to just Florida. Shrug.

So now the argument is to go with CCRs to keep the GUE tech diving pipeline from shrinking, is that right?

Out of curiosity, when will someone make a cogent argument about why deep air is preferable over trimix that doesn’t involve cost or apartment living?

 

[wetb4igetinthewater]

So now the argument is to go with CCRs to keep the GUE tech diving pipeline from shrinking, is that right?

I think OC technical diving will shrink dramatically if the price of helium continues on its trajectory and its availability continues to shrink.

Out of curiosity, when will someone make a cogent argument about why deep air is preferable over trimix that doesn’t involve cost or apartment living?

Deep air is a poor choice given gas density/narcosis issues. Hasn't science proven that? Sure, I get some people like to ignore it, but that's on them.

 

[Adobo]

I think OC technical diving will shrink dramatically if the price of helium continues on its trajectory and its availability continues to shrink.

Deep air is a poor choice given gas density/narcosis issues. Hasn't science proven that? Sure, I get some people like to ignore it, but that's on them.

That’s what the OP is certified to do today. Air to 45 meters. That’s the traditional progression, right? Intro to tech then AN/DP which then allows the diver to dive air to 45 meters. Whereas GUE has fundies then tech 1 which allows divers to dive to 50 meters on 18/45.

My point is, the argument folks are advancing against trimix sooner rather than later is all around either cost or convenience. I dunno. Sounds like nickel rocketry to me. Never does anyone profer an argument that states that the other way is better. That it is safer. That it builds a better diver. Only that it is cheaper.

 

[wetb4igetinthewater]

That’s what the OP is certified to do today. Air to 45 meters.

My point is, the argument folks are advancing against trimix sooner rather than later is all around either cost or convenience. I dunno. Sounds like nickel rocketry to me. Never does anyone profer an argument that states that the other way is better. That it is safer. That it builds a better diver. Only that it is cheaper.

I get that people will justify deep air due to cost reasons. However, there is the safety aspect. Now since properly maintained equipment is quite reliable (never perfectly reliable), if you are at 50 meters on air, and something happens when you have a gas density well over 6.2 g / L, you better be able to move at a sloth's pace and maintain slow yoga breaths or you could easily wind up dead.

Spending $$$$$ versus being dead possibly if there's an emergency? Hmmm, I think I know what I will choose.

GUE developed their rules before the science came by and validated their practice.

I don't wish to invalidate anything GUE does. I think when it comes to skills and safety, they are top notch. I just feel that economics may play a part if they want to maintain their size and/or continue to grow.

 

[crofrog]

Whereas GUE has fundies then tech 1 which allows divers to dive to 50 meters on 18/45.

You could do rec3 in between, and on that note I’ll be leaving for AJ goes on a rant

 

[elgoog]

You could do rec3 in between, and on that note I’ll be leaving for AJ goes on a rant

Just so you know, I've reported you to SB mods for inciting violence

 

[PfcAJ]

You could do rec3 in between, and on that note I’ll be leaving for AJ goes on a rant

 

[barth]

But wasn't the requirements prior to T2 being a requirement? My memory could be incorrect on that.

In the past gue divers who were certified for tech 2 dives did a training which was almost the same as ccr 1. When the training was finished they did 25 rec dives and when that was done they were allowed to do dives in tech 2 range with the JJ.

Nowadays tech 2, cave 2 and dpv cave divers do ccr 1. The do 25 rec dives. After that they do dives in t2 range in caves with dpv.

People are missing a lot of experience doing dives oc is not the same as cc.

With oc training like cave 1, cave 2 and tech 1 divers were doing the dives the were certified for during courses. Nowadays divers combine all their certificates and doing dives without the knowledge and experience required for the dives.

I give 1 example, before I did a tech dive with a ccr 1 diver we were at the surface. He was asking me how he should set his perdix in cc mode (it was in oc mode). After the dive hit perdix was in error (maybe not error, but missed deco) because he didn’t switch his perdix from setpoint 0.7 to 1.2. This kind of things are happening because he did never do a tech dive during ccr 1, only dives with max depth of 18 meter / 30 feet.

It’s viable. You just have to pay for it.

Do it right or don’t do it. If you can’t afford the sport, then that’s on you. Don’t expect the standards to lower to accommodate your finances.

More experience on the rebreather might be more viable then tech 2. Extra training with ccr might be more viable then extra oc training.

I’m not telling that T2 experience is not worth anything. But maybe there are better choices.

Tomorrow I will dive a mine, I will use my JJ.

There is also a cave 1 team. Water level is between 27 and 31 meter. Should I tell them they should use 30/30 or they shouldn’t do the dive if they can’t afford 30/30 ?i’m sure they will use ean32.

My bailout is 18/45 and 30/30 (+ean50 +oxygen).

 

[Wibble]

Standard gases are slick because you can put in the helium component and then top with 32% and you’ll end up with the standard gas.

Al80, put in 1350psi of helium, top with 32%, bang 18/45.

This ratio works on partially filled bottles too. Al80 at 1500? Easy, put in 675psi of helium and top off with 32. Bing bong 18/45.

A couple HE bottles, some gas to run your booster (double 120s?) and a local shop with nitrox and you’re in bidniss. Helps if you have frands to help spread the cost around. Trust me, you’ll be the coolest cat in town.

Alternatively, your gas mixologist pulls his phone out of his back pocket, enters the parameters -- current gas & pressure, target gas & pressure -- then boosts in whatever's available.

Few places outside of Cave Country bank helium. Have never found a place anywhere that banks and doesn't do partial blending.

Again, the technology has moved on. We have gas mixing programs (apps) available to all.

I mix my own fills from my three twinset banking cylinders. Because I am filling 3 litre steel cylinders, it's very easy. I just need my gas dealer to occasionally (cave) fill the bank cylinders. I'll get 10 or more dives out of a fresh set for dives down to 70m/230ft (e.g. 15/55). It's like paying for one open circuit dive and I get 10 or more.

I tend to mix standard gasses for my dives as it’s easier to remember the MOD for them (although with CCR you don’t use 1.4 PPO2 for diluent, you aim for lower 1.1 in case you need to do a dil flush)

 

[LanceRiley]

Goodness knows how anyone could become Tec2 without spending many thousands on helium.

Take the OP; has gone as far as is practical with extended range but unless he's particularly wealthy and has a secret source of lots of helium, his future's either shallow or CCR. It won't be GUE because the costs to achieve the minimum experience would bankrupt a small nation.

This kind of brings up the point that the other agencies have pretty much caught up with standards (agreed, GUE's training is premium) and most people are taught DIR philosophies. It would be really surprising if the OP wasn't taught with a longhose and both deco cylinders left. Valve drills would be the same as GUE's (without the special signalling).

It has to be accepted that CCR is different. There's no longhose (except for the 0.1% diving on the GUE JJ) and balancing a CCR rig is more sensitive so diving Lean Left Rich Right is wholly acceptable (as is bungeeing the cylinders back sidemount style). Whilst a backmount DIR proponent would have an apoplectic fit, everyone else just gets on with it.


The crux is... What is DIR? It should be "best practices" for safe and efficient diving.

I dive with both stages in the left and longhose. Valve drills are with light signalling