BackMounted Doubles and mixed gas - is that technical?

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You have lots diving experience, you have some of the gear, you have great wrecks like the Stolt that are fun with more bottom time. It seems like you are a good candidate to actually do the deco training and do this the right way. Why mess around with a non-standard and potentially dangerous approaches when you can get some training that will really open up your diving?

I didn't get tech trained to do very deep wrecks, I just wanted to be able to spend more time at moderate depths.

And if you REALLY like the idea of doing the top part of the wreck on a richer mix than the bottom to stretch out those NDLs, maybe constant PO2 is for you... Why settle for just two mixes when you can have a machine that will give you whatever you want? :D
If someone is trying to save money on Nitrox fills maybe CCR is not the way to go?

With rec diving there are only 2 failure modes for the reg in your mouth: you can breathe or you can’t. The troubleshooting flow chart is simple and you know immediately if you are in trouble.

With tech diving you add the failure mode of being able to breathe but not necessarily having a life supporting gas, but as long as you haven’t changed regs then if you were good you should still be good.

CCR adds the failure mode of not having a breathable gas even though you have not changed anything (one breath from death etc)

I would respectfully submit that the OP is not really in a mindspace to safely use a breather, yet.

WRT the question of a slung bottle, that would make it easier to avoid a hot switch but as long as there is a reg on you that will kill you, it’s going to be waiting for just that. Training is needed to mitigate the risk.

There’s nothing down there worth dying for.
 
So obviously - most are in the camp of carry your back gas all the same mix - as needed sling your deco or mixed gas separately.

Reasonable process and relatively risk free... Better folks than I have died breathing the wrong mix - so from a perspective of safety that seems reasonable.
From a perspective of taking AN/DP class - it is not in the cards just yet... Hope to be in the future.

If you have a lot of wrecks in your neck of the woods in the 100-120ft range I would just dive them without deco gas and do limited amount of deco on backgas (let's say up to 20 minutes). As long as you plan adequate reserve in your gas and have redundancy (not sure if non manifolded doubles are that but I'll leave that in the middle) you should be ok.

But for sure best course of action is to take an AN/DP style of course. Definitely if you want to speed up decompression using a deco gas. Look for a good instructor and you'll learn a lot. The course will give you more tools to do this kind of dives and if after the course you decide to do it differently at least you know the safe practises and standards.

Next it will allow you to extend your dive time significantly on these 100-130ft wrecks and it will give you a check up on where you are at from buyoancy, trim and general skills point of view.

At the moment you are like a new diver (you are not, I know, but you are when it comes to staged decompression diving) who has a certain rationale for doing things but not the training or background experience to validate that rationale. In your world it all seems perfectly fine what you are doing but "you don't know what you don't know" and because of that you are putting yourself at serious risk.

Cheers

B
 
I would like to keep everything simple:
Recreational: Single or twin set but NO deco whatsoever.
Tec: Deco and overhead.
CCR is unique and a completely different ballgame.

Therefore what the OP suggested is "Tec" in my dictionary. Seek proper training.
 
If someone is trying to save money on Nitrox fills maybe CCR is not the way to go?

Yeah, I was kidding about the rebreather (hence the emoticon). But not about the tech training. If the OP already has most of the equipment he needs and lives near the NJ shore, it's not such a big step to actually do the training to do the kind of diving that he is already edging towards in a haphazard way.
 
Recreational: Single or twin set but NO deco whatsoever.

That sort of rules out a pony or sidemount with even two small tanks. A clearer, and maybe assumed, rec rule might be no unbreathable gas (and no deco).

The OP did not go into deco, they used 40% to explore the top of the wreck longer and have less nitrogen for second dive. Plus likely some faster off gassing on ascent. (a few things wrong, but no actual deco ceiling)
 
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I'm not a technical diver but I would not consider carrying a gas that is toxic, at the planned depth, to be "recreational". Just having that on your person is an added risk that is just not present in recreational diving.
 
Recreational: Single or twin set but NO deco whatsoever.

Under your rule - I was Recreational diving... I was twinset and never hit deco... Ok beating this dead horse but I want to clarify...
 
You had your secondary on a gas that was unbreathable at the bottom. That's definitely not rec, but I think the tec divers that have replied wouldn't consider it tec either since the other elements required for true tech diving weren't there i.e. true redundancy and adequate training to mention some.

I'm not trying to have a go at you but it's important to say this for the future viewers of this thread.
 
I think that we get caught up in semantics in these threads. "Technical" is a poorly defined term. In my opinion, any dive is a recreational dive unless you are getting paid to do it. But of course the commonly used definition of recreational diving is a dive with no physical or decompression overhead.

"Technical" to me is more of a mindset than a particular profile. You plan the dive ahead of time by calculating NDLs, gas usage, turn times, contingency ascent plans, etc... You could do a technical dive without breaking NDLs by this definition.

The answer to the OP's question "Is this a technical dive?" would be "that depends on your definition of technical". The far more interesting question is what changes should the OP make to his diving, if any.
 
I'm not trying to have a go at you but it's important to say this for the future viewers of this thread.

And for the record - I agree with your assessment.
I remember a thread that Akimbo did on penetrations - something like - If you would not let your brother who has a pregnant wife do that dive - what the hell are you doing?
In that spirit - I was missing the safety of myself or others that may come knocking for OOG scenarios. I was and do think selfishly at times - so the take away is redundancy and process. Cover yourself with enough back gas to do your incurred deco should your mix gas become completely unusable. In my scenario I had a sling for the gas but chose to put it on my back. Sling the gas and don't put the regulator on my person until I have checked the depth, marked my switch and have everything squared away - then breath away.
Everyone has opinions and everyone has a risk threshold - I chose a risk that I did not see and it was pointed out. I have taken note and will think about this for a while and determine my best course of action.
I lived to tell about it and got further in my understanding of knowing what you don't know or think about...
 

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