Rec Vs. Technical???

[CptTightPants21]

No doubt I would not do it past 90ft I have only done nitrox when doing multiple 40-60 ft dives

Then I am confused why you would even mention 120 on 36%.

I stated above what I belive the two choices are. I recommend buying or getting you hands on some dive software and simulating a variety of different dives. If the dive lengths and deco times work for you then you can go with option 1. If you don't like your deco obligations then you can go with option 2.

I know you mentioned that you had a lot of 80s, so it probably easier to go the doubles route since you will need at least a 108 and maybe larger for option 2.

 

[Dr. Lecter]

I know you mentioned that you had a lot of 80s, so it probably easier to go the doubles route since you will need at least a 108 and maybe larger for option 2.

Hopefully the AN/DP class would teach him that a single tank + a bottle of 100% isn't necessarily going to work in terms of redundancy, though I suppose toxing after a switch to O2 at 120' might beat drowning while fully conscious at 120'.

 

[Octopusprime]

OR.. you read up on it a little, buy a high pressure 149 cu-ft tank, fill it with some nitrox of the appropriate flavor, clip a 30 or 40 cu-ft bottle off as a bailout bottle (full of air) and keep your deco under 15 minutes or so.

EDIT: then again, if you are using nitrox for 40 ft dives, then maybe this isn't for you?

why is it when someone asks a question they say divings not for you... The post was days ago... The point of the questions here are about exceeding non deco limits... And to your nitrox point. You obvously do not do a lot of repetitive dives. I said 40-60 ft If you do 3 60ft dives for 45 min with 30 min surface intervals you will max out your deco time. I can get 5 dives in before noon on nitrox. On air I will add 1-2 hr of surface interval.

 

[CptTightPants21]

Hopefully the AN/DP class would teach him that a single tank + a bottle of 100% isn't necessarily going to work in terms of redundancy, though I suppose toxing after a switch to O2 at 120' might beat drowning while fully conscious at 120'.

Agreed, I should have clarified a little bit more. I believe the right way to go would be doubles with a deco bottle and take the full intro/AN/Deco route. The options I listed were the less optimal and cheaper/cutting corners routes, but still viable options.

 

[Octopusprime]

Then I am confused why you would even mention 120 on 36%.

I stated above what I belive the two choices are. I recommend buying or getting you hands on some dive software and simulating a variety of different dives. If the dive lengths and deco times work for you then you can go with option 1. If you don't like your deco obligations then you can go with option 2.

I know you mentioned that you had a lot of 80s, so it probably easier to go the doubles route since you will need at least a 108 and maybe larger for option 2.

Maybe it would be helpful to share a couple options of dive software for simulating ?
im looking at doubles valves and extra regs now. Going to go to DRIS

 

[C Dub]

My take: There is no middle ground between tech & rec. At least I've not found one. You either have to go full tilt and get training and equipment or be satisfied with rec.
That means time, expense and commitment. For me, all I wanted was a few more minutes on 90-100 ft wrecks that could/would include a FEW minutes of deco. I didn't want to do doubles or expensive helium (that's what happens in some agencies) long hangs etc. But there really isn't an agency (that I've found) that teaches 'a little deco'
Just my take

IANTD teaches advanced nitrox and deco procedures. Up to 15 minutes of deco with up to 100% O2, if I recall correctly. Fits your description perfectly.

 

[CptTightPants21]

Maybe it would be helpful to share a couple options of dive software for simulating ?
im looking at doubles valves and extra regs now. Going to go to DRIS

Deco planner and V-planner are some of the more popular programs. If you know any tech divers at your shop, you could probably give their version a spin.

 

[ddmattos]

Octopusprime please keep the working part of your dive at 1.40 PPO2 or less (deco =<1.60 PPO2). It's just not worth it. Your taking a chance that fellow rec divers will be able to help if you tox. You will get such training during Adv. nitrox/Stgd deco courses.

I'm not saying you are or want to, but pushing limits or stretching NDLs is not a good mindset. That's why your here asking questions.

When doing dives with multiple cylinders, that amount of gas could get you into trouble. I'm not talking about slinging a 40cf for bailout. You should really plan your dives with Multdeco which I believe allows you to plan dives using 40% or lower with the demo version. Read up on your algorithms to learn about conservative settings. Start with VPM or Buhlmann 16c with gradient factors. You want to watch your O2 exposure since you may be pushing limits over time.

With that said, I still recommend taking the adv nitrox/stgd deco. It's full of such great stuff (knowledge and skills). Finding a good instructor and discussing about being interested but hesitant to commit capital for doubles will not hurt.

Stay safe.

 

[Octopusprime]

IANTD teaches advanced nitrox and deco procedures. Up to 15 minutes of deco with up to 100% O2, if I recall correctly. Fits your description perfectly.

Advanced EANx Diver (OC, SCR, CCR) looks like like a good fit. I do not know of any iantd shops I be been doing Padi I'm assuming my Padi dives would count

---------- Post added February 4th, 2015 at 10:51 PM ----------

My plan for the next year is to do more ND Lake Michigan dives. Work on getting completely comfortable in dry suit before trying to do mandatory deco stops. Looking for dives in the 90ft range staying in non deco limits.

 

[TSandM]

There really isn't a "bright line" between recreational and technical diving. The deeper you go, or the longer you stay, the less desirable the surface is as an option to solve problems. Eventually, it really ISN'T an option. But in the grey zone, you could have five divers do the same dive, with three different ways of calculating no deco time, and have four of those divers concluding that they had no deco obligation, while the fifth showed a 10 minute obligation at 10 feet (this happened to me, with a group; my husband was the diver with the deco obligation). At this point, is the surface safe for anybody? Safe for the people with cleared computers, but not for my husband?

You are looking for a class that will teach you how to do dives that incur a "little deco" on a single tank, without a deco gas. I don't think you'll find that class in the US. Most agencies here have decided that any deco obligation requires redundancy -- at least an H valve and double first stages, or preferably two backgas tanks. And since you can do a pretty satisfying dive at 100 feet on 32% without any deco obligation, most agencies look at their deco classes as running deeper than that, and a lot of those agencies want you on helium (but not all).

It would seem to me that, if you can't find a class to teach you what you want to do, that maybe a whole lot of people who know a good deal about this sport have concluded that what you want to do may be unwise.