First time of tech doubles, had a bit of trouble...

[Doc Harry]

Relax. "Every action has an equal and opposite reaction." Tensing up only creates its own roll momentum. You gotta be really relaxed.

 

[Celt]

If you drop those tanks in the water and they float plate up that’s the way they want to lie. So if you’re neutral and relaxed they’ll turn you face up and there’s nothing you can do about it in your present setup.

 

[sea_ledford]

I realize this is an old post that has been revived, and I hope the OP has figured things out after a year+!

But for others looking at this thread for advice, one thing that seems to help new doubles divers is just a mindset change. In a single, you are wearing the tank on your back. With doubles, you are hanging from your tanks/wing. Think of it as if you are a blimp, not a jet.

 

[Azraelien]

Can confirm on the '20 or so dives to get comfortable' element of tech diving. Having taken several PADI/SSI specialities with their '4 dives and you're good' setup, I was a little worried when at the start of our ITT, having just acquired a drysuit and sidemount rig, I was told casually that 'yeah roughly 50 dives should be enough to feel comfortable in this setup, then we can start real training' - I honestly thought that having taken the drysuit course I *was* comfortable. 20-odd dives later and I was starting to understand what 'comfortable' meant; 60-odd later, and well into month 10 of our ITT course, I can see why that number was given - Comfort levels are through the roof, and it's starting to feel unnatural NOT to be drysuited up and running blindfolded or no mask drills at all hours of day and night..

 

[acreichman]

Just have to say that this thread threw me for a loop. I just ordered a drysuit and almost pulled the trigger on a set of HP117 doubles. I've been looking for advice on how others have managed this transition so this thread was absolutely spot on. What made it weird is that my name is also Aaron so seeing posts addressed to me about the exact issues I have questions on was freaky. I briefly considered whether I might be reading a post from my future self through some weird, limited form of time travel.

@Aaron Harmon on the off chance you are me from the future (or I'm you from the past), how did doubles and the drysuit end up working out? What recommendations would you make to your past self on how best to make the transition?

 

[rvojr]

I'm in the same boat figuratively. 18 single tank dry suit dives since July. I have just done dives 1 and 2 with doubles plus one in the pool. HP100 and HP120 trim out nice without the issues mention here for now. I'm not sure what the difference is other than 7.25" tanks vs 8". I am definitely reacting too quickly and not waiting a few more seconds for the additional momentum over the single tanks. Hopefully the comfort level gets better after this weekend at a quarry enough to be able to do some boat dives.

 

[ScubaSamScubaStevesFather]

Ok, I have 80 dives in the last 2 years or so, couple of different certs. I feel pretty good about my rec diving and my confidence has grown tremendously in the last year.

O.K. on to the reason for the post...

So, I live on the Great Lakes and I recently decided to buy a dry suit and take the tech diving classes so that I can dive some of the deeper wrecks.

I bought a new 117 CF doubles setup along with back plate, webbing redundant 60lb wing etc. Basically everything I'd need to take the TDI intro and beyond.

Currently I am taking TDI intro to tech.

My dry suit will not be here for 4 to 6 weeks but my doubles came in and my instructor wanted to get my rig set up and get me comfortable in it.

I think it still needs some minor adjustment, but last night, I dove in the pool with it and we went over some basic skills.

Here's the issue. I felt like I'd never dove in my life. These double 117s are night and day to the single steel 80 I'm accustomed to. I felt like I was fighting to stay balanced side to side under the water. If the tanks shifted left or right, it felt like they were going to roll me over. Forget about intentionally inverting or turning side ways. I had to stay perfectly flat. I struggled to stay upright and constantly felt that if the tanks gained any momentum in one direction or the other, they were going to roll me.

I had to use a fair bit of air to stay neutrally buoyant, I was in swim trunks and nothing else.

The instructor demonstrated a few kicks and some reg drills that he wants me to work on in the pool until I'm trained in my drysuit, but I was fighting so hard to stay balanced side to side that it was nearly impossible to concentrate on anything else.

My set up is..

Double HP Steel 117s
Apeks Steel Back plate and Harness
Apeks WTX60R (redundant) bladder.

After the pool work, I was really discouraged... I worried that for whatever reason, I dont have this in me. I hope thats not true because rec has been my nonstop passion for 2 years...

Any ideas or help would be greatly appreciated...

Had the same experience; my first confined water dive w/ doubles was one of the worst "dive" experiences I've had in 20 years. Get heavier fins and/or extend your legs.

 

[Nick_Radov]

you just need to be patient and work with your instructor

No. Any instructor who would tolerate a student using such an unbalanced, messed-up rig is obviously not qualified to teach tech diving. Don't be patient. Find a better instructor.

 

[Stoo]

Any ideas or help would be greatly appreciated...

Ignore it for now. You likely have something like 20+ pounds of iron trying to sink you between the tanks and plate. As a result, you had to add a similar amount of air in to your wing. Nasty combo...

You might consider wearing a wetsuit, even though you may melt. Nobody in ther right mind would wear twin 117s, a steel plate and a bathing suit. It's like diving with a bank vault on your bank.


As others have suggested, so if you can swap out the plate for AL or lexan, and maybe even the tanks for AL 80s or something. I think you'll find that once you get the drysuit dialed, adding twin 117s will work fine. They're beasts though for sure. I have twin LP 80s, LP 95s and HP 120s for bigger dives. At the start of the dive, I still need some gas in my wing (even without a weightbelt) and a plastic wing.

 

[H0tDog45]

Is it possible your harness is too loose which is causing the tanks to shift?

Keep us posted.

Agreed. I would check your harness. When I started doubles I had some issues with the tanks rolling and it was due to the harness shoulder straps being way too loose.