"Not quite DIR"

[LiteHedded]

I should probably stay out of this one. I'm one of the 30/30 weirdos

 

[MXGratefulDiver]

I should probably stay out of this one. I'm one of the 30/30 weirdos

Dude ... y'er so gonna die ...

... Bob (Grateful Diver)

 

[MXGratefulDiver]

Wow uh, I almost feel like I need to start a new thread.

So there's two questions I have, really.

The first is (predictably) deep air (or deep nitrox, whatever). I ask for a DIR sort of angle, because to a lot of people 130' on air is no big deal. To others, 165' is no big deal. I've felt some narc around 100-110'. My interest is how far "<100'" people are willing to stretch that in the total absence of available helium. How about in the absence of affordable helium?

The second is additional tanks for deeper dives where manifolded doubles are not an option. My inclination would be that a single tank of backgas and a single stage would be more compatible with the DIR style of diving than independent doubles. However, it seems that the streamlining of indies would be better.

Well, you KNOW the DIR angle already.

What you're really asking is (a) how willing is someone to not consider themselves DIR when faced with those choices, and (b) what's your risk tolerance?

Me, I'll push 120 on nitrox (I just don't do air outside of a swimming pool if I can help it) ... any deeper than that and I want to be sounding like a chipmunk when I talk. As for deeper dives, I want sufficient reserves and redundancy. I've been several places where manifolded doubles aren't an option ... that's one reason I went sidemount. Prior to that, if I didn't have doubles I'd keep it to recreational depths.

Of course, those are not DIR answers ... the DIR answer is if you don't have appropriate tanks and gas, you don't do the dive.

... Bob (Grateful Diver)

 

[guyharrisonphoto]

This is "sort of" a related question. I am an experienced diver and recently (9 months ago) moved to a DIR-style gear set up, which I really like very much.

I have pretty good experience on deep dives with air (210 was my max) and, because of that, I really appreciate and hope to partake in the joy of trimix and diving without narcosis issues.

However, the training systems I have seen (PADI, IATD) require you to go "nitrox" (done), then "advanced nitrox/decompression procedures" for diving down to 140, and then "extended range nitrox" for even deeper, and only at the end, after thousands of dollars, "trimix."

My question is, once you have done advanced nitrox (which I would want), why is there no option to then get trimix training? Especially when the benefits of trimix begin at 110-120?
Or, am I just not aware of a system that would offer that.

 

[Rainer]

GUE's progression:

Fundies -> T1 (covers 50% and O2 deco, 30/30, 21/35, and 18/45)

This is "sort of" a related question. I am an experienced diver and recently (9 months ago) moved to a DIR-style gear set up, which I really like very much.

I have pretty good experience on deep dives with air (210 was my max) and, because of that, I really appreciate and hope to partake in the joy of trimix and diving without narcosis issues.

However, the training systems I have seen (PADI, IATD) require you to go "nitrox" (done), then "advanced nitrox/decompression procedures" for diving down to 140, and then "extended range nitrox" for even deeper, and only at the end, after thousands of dollars, "trimix."

My question is, once you have done advanced nitrox (which I would want), why is there no option to then get trimix training? Especially when the benefits of trimix begin at 110-120?
Or, am I just not aware of a system that would offer that.

 

[MXGratefulDiver]

This is "sort of" a related question. I am an experienced diver and recently (9 months ago) moved to a DIR-style gear set up, which I really like very much.

I have pretty good experience on deep dives with air (210 was my max) and, because of that, I really appreciate and hope to partake in the joy of trimix and diving without narcosis issues.

However, the training systems I have seen (PADI, IATD) require you to go "nitrox" (done), then "advanced nitrox/decompression procedures" for diving down to 140, and then "extended range nitrox" for even deeper, and only at the end, after thousands of dollars, "trimix."

My question is, once you have done advanced nitrox (which I would want), why is there no option to then get trimix training? Especially when the benefits of trimix begin at 110-120?
Or, am I just not aware of a system that would offer that.

There are many systems that offer that. I did almost all of my technical training with NAUI ... with a few forays into other agencies for specific classes. NAUI no longer condones deep air diving ... in fact, they've combined AN/DP with a helitrox class so that you are doing your 150-foot dives on a 20% helium mix.

My progression went IANTD Rec. Trimix -> NAUI AN/DP -> NAUI Trimix I -> NAUI Trimix II ... there was no extended range involved, and I was diving helium on recreational-level deep dives before I even got into any tech classes ...

... Bob (Grateful Diver)

 

[Ragnar]

My question is, once you have done advanced nitrox (which I would want), why is there no option to then get trimix training? Especially when the benefits of trimix begin at 110-120?
Or, am I just not aware of a system that would offer that.

You can with TDI right after AN/DP.

 

[chokolad]

GUE's progression:

Fundies -> T1 (covers 50% and O2 deco, 30/30, 21/35, and 18/45)

i'd say GUE now can be Fundies -> Rec 3( covers 30/30, 21/35 and 32% for Deco) -> T1

 

[Rainer]

Personally, I just don't see the need (or desire) for R3. If you lack the skills for T1 (or a Fundies tech pass), what business do you have with "minor" mandatory deco obligations? 32% just isn't an ideal deco gas (for max 130' dives), especially if you switch at 70' (low PPO2). Mixed teams of T1 and R3 don't make sense (different deco gases and schedules). 21/35 for the 100-130' range isn't ideal (more than enough helium, and so little O2 that NDLs are really short); just a lot of money to spend for short bottom times at the deeper end of the certified depth range. I'd rather just push 30/30 (~120') or take 25/25 (~130'), and definitely O2 for deco. For me, R3 is just an awkward duck.

In any case, Fundies->T1 is still a great two class option.

i'd say GUE now can be Fundies -> Rec 3( covers 30/30, 21/35 and 32% for Deco) -> T1

 

[Jaydubya]

You can with TDI right after AN/DP.

GUE and IANTD do it right by encouraging (or even requiring in the case of GUE) the use of helium at an early stage. I don't know what state of the art is with TDI but the local customs are air/nitrox to the 100-150 range for AN/DP class and then skipping extended range and going straight into (normoxic) trimix. I don't know a single person who has taken an extended range class in recent years other than the PADI Tec sheep being fleeced at the LDS.