DIR- Generic Tdi Normoxic trimix or CCR?

[Wibble]

How can that be "doing it right"? It's a specific tool that's been highly modified for the specific problems in caves. It makes a perfectly good rebreather, the JJ, far heavier and non-standard -- compared with virtually every other rebreather on the market (not counting all the sidemount ones in that list).

Where are those "standards" and where is the responsible committee that looks after the evolution of those standards?

 

[Adobo]

Where's that defined then?

Seriously, where are the "standards" documents describing what is DIR and what isn't?

Backup computer -- on your teammate's wrist? Use of helmet mounted torches? Drills... Standard gasses...???

Some context since according to your profile, you have been diving for 10 years at most…

DiR or doing it right was coined by GI3 for scuba decades ago. It is how they (wkpp) did it. GI3’s dive buddy, Jarrod, started his own agency (GUE) to teach how they did it. One of the lead instructors at the beginning was AG (of UTD fame. Side note, unified team diving was coined by Lynne, may she Rest In Peace. AG, so far as I can tell, simply took the name after seeing it here in SB. )

Today, as far as I can tell, GUE has evolved to cover areas beyond what might be standard in the wkpp. Admittedly, I know **** about what the wkpp does beyond what they have shared in the internet. But I do know that GUE has introduced classes that have little utility for cave divers (eg. rec 3).

I dunno about the rest of the diving world but for me, DiR is what it always has been - how they do it in the WKPP. If you have no extensive experience taking GUE classes (and doing the dives) and you don’t dive with the wkpp, IMHO, you should be asking questions about what is DiR, not answering them.

 

[Wibble]

Well spotted. Ten years in a couple of weeks

Am well aware of the DIR wars and GI3's missives also the change in stance about 7 years ago. Had a dalliance with GUE in the beginning of my career.

As previously said, the principles of DIR has done so much for diver safety and standards, certainly compared with the wild-west of decades ago.

Whilst DIR evolved from cave diving, it's the wider world that has adopted much of its concepts. Longhose, standard gases, kit configuration.

The challenge now is the brave new world of helium rationing; the old standards simply cannot be used -- nobody's going to dive 21/35 for a 35m/115ft dive on open circuit. If you're *truly* wedded to DIR then you would never dive without standard gasses. Even if they're adapted, for example 25/25 down to 45m/150ft, it's still not viable on open circuit.

And here we are back at the nub of the matter. Our OP wants to dive deep and needs a way forwards. Either it's back to Causteau's day and deep air (please don't), or it's CCR.

Just for one moment accept that the only true DIR-compliant rebreather is a GUE JJ. How will you ever get to use that if you have to be T2 qualified in an environment without helium?

Practically this means the route to CCR for our OP is not GUE, but is TDI, IANTD and all the other agencies who are running the manufacturer-specific MOD1 (which allows helium) and MOD2 classes (which adds long deco within bailout constraints).

 

[PfcAJ]

Well spotted. Ten years in a couple of weeks

Am well aware of the DIR wars and GI3's missives also the change in stance about 7 years ago. Had a dalliance with GUE in the beginning of my career.

As previously said, the principles of DIR has done so much for diver safety and standards, certainly compared with the wild-west of decades ago.

Whilst DIR evolved from cave diving, it's the wider world that has adopted much of its concepts. Longhose, standard gases, kit configuration.

The challenge now is the brave new world of helium rationing; the old standards simply cannot be used -- nobody's going to dive 21/35 for a 35m/115ft dive on open circuit. If you're *truly* wedded to DIR then you would never dive without standard gasses. Even if they're adapted, for example 25/25 down to 45m/150ft, it's still not viable on open circuit.

And here we are back at the nub of the matter. Our OP wants to dive deep and needs a way forwards. Either it's back to Causteau's day and deep air (please don't), or it's CCR.

Just for one moment accept that the only true DIR-compliant rebreather is a GUE JJ. How will you ever get to use that if you have to be T2 qualified in an environment without helium?

Practically this means the route to CCR for our OP is not GUE, but is TDI, IANTD and all the other agencies who are running the manufacturer-specific MOD1 (which allows helium) and MOD2 classes (which adds long deco within bailout constraints).

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.

 

[Alaskan Scuba Dude]

Don’t expect the standards to lower to accommodate your finances.

SDI/TDI standards are tried and tested by technical divers around the world.
Just like the mainstream dive algorithms.

 

[elgoog]

Even if they're adapted, for example 25/25 down to 45m/150ft, it's still not viable on open circuit.

Not viable? Really? I'm an about-to-be T1 diver and using 21/35 or 18/45 for 150-170' dives with a single deco gas is perfectly viable for the number and frequency of dives I do every month. And I'm certainly not made of money.
There's quite a few divers who do this at my local dive sites and they're not all GUE either.

Just for one moment accept that the only true DIR-compliant rebreather is a GUE JJ. How will you ever get to use that if you have to be T2 qualified in an environment without helium?

You don't need T2 for the JJ CCR1 class - T1 and 25 dives at that level is the requirement and always has been. The RB80 SCR needed T2. Certainly 25 dives to 150' with a single deco gas switch is not too much to ask before going to rebreather that would require you to do the same if you had to bailout, is it?

 

[wetb4igetinthewater]

Not viable? Really? I'm an about-to-be T1 diver and using 21/35 or 18/45 for 150-170' dives with a single deco gas is perfectly viable for the number and frequency of dives I do every month. And I'm certainly not made of money.
There's quite a few divers who do this at my local dive sites and they're not all GUE either.

How much are you paying per liter/cubic foot of helium today?

[Edit: looking for a good source for tracking cost of helium]

 

[Wibble]

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.

Therefore anyone not diving to the only true standards of DIR are wrong? Could have been uttered by GI3.

Some standards are guidance, some are critical. It's down to the diver to differentiate. Gasses are not set in stone: what if the gas mixologist was a bit out -- would you cancel the dive or live with what you have? Obviously depends on the parameters and the dive profile and your flexibility. The wreck's slated at 28m/94ft but it's high tide so 33m/110ft to the bottom: would you dive it on 32% or know that 33m is a perfectly safe PPO2 of 1.38? Or even spending $100+ for the helium to do a 33m dive rather than $10 for 32%. How about diving to 38m/126ft - spend $100+ or $10 for 28%? What if the mixologist's gas booster was out of action and you can't get a full fill of 100%; do an air top and get a full fill of 80% (same deco times as 100%).

Pragmatism. Sadly often missing.

 

[PfcAJ]

Therefore anyone not diving to the only true standards of DIR are wrong? Could have been uttered by GI3.

Some standards are guidance, some are critical. It's down to the diver to differentiate. Gasses are not set in stone: what if the gas mixologist was a bit out -- would you cancel the dive or live with what you have? Obviously depends on the parameters and the dive profile and your flexibility. The wreck's slated at 28m/94ft but it's high tide so 33m/110ft to the bottom: would you dive it on 32% or know that 33m is a perfectly safe PPO2 of 1.38? Or even spending $100+ for the helium to do a 33m dive rather than $10 for 32%. How about diving to 38m/126ft - spend $100+ or $10 for 28%? What if the mixologist's gas booster was out of action and you can't get a full fill of 100%; do an air top and get a full fill of 80% (same deco times as 100%).

Pragmatism. Sadly often missing.

Somehow we manage just fine.

May is National Stroke Awareness month though. Breathing 80% is a classic symptom. Always be on the lookout and invoke Rules 1 and 2 if you suspect anything, and don’t be afraid to resort to Option 1 if need be.

 

[Wibble]

The diving community's a much calmer place without the likes of GI3's haughty disdain. Zealotry is never a good method of persuasion.