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

[Aaron Harmon]

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...

 

[decompression]

Those tanks are beasts......I start my tech students with double AL80s in the pool.........
You needed so much air in your wing that the dynamic shift of all that air moved you all over the place. Of course it felt like a newbie. I try at all costs to avoid that.
It will get easier to manage once in the open water........drysuit also helps balance.......
Keep in mind, intro to tech should be a majority focus on proper trim, balance and control in the water........once those are MASTERED then the basic 6 and other skills can be performed in mid water......keep us informed on your progress.

 

[MichaelMc]

While fighting a very negative tank above you can be necessary for tech, you might retrieve a bit of balance by switching to AL plate and putting the freed up ballast as lead on the very front of your harness (chest or waist). The twin AL80s would be easier for that, but if you're stuck with the 117s, the ballast from the plate may be the only option to play with.

Though from your comment on air, you might be over weighted at that, but that only sounded as if it was the pool, so in the drysuit you might be ok, on having ballast you can put on your front to balance out the negative tanks on your back.

 

[SandyRobinson]

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

Keep us posted.

 

[drk5036]

without a wetsuit, this is a really heavy setup, and you'll need a lot of air in the bladder to overcome that. Furthermore, based on your planned diving, you won't be using those tanks without an buoyant thermal protection, so I'm not sure the skills would exactly translate anyway. Why not try it out with a 7 mm wetsuit? that'll give you something like 15-20 pounds of extra lift, minimizing the weight differential between your body and the tanks. I think that would likely help some.

 

[lermontov]

you just need to be patient and work with your instructor to pick away at it till you get comfy- here's the thing, tech diving by definition is technical and requires more equipment and more skills - also tech diving is a lot about problem solving and fine tuning -i can promise you in 6 months of regular diving youll have it sorted and youll reread your post and smile to yourself

 

[MichaelMc]

you just need to be patient and work with your instructor to pick away at it till you get comfy- here's the thing, tech diving by definition is technical and requires more equipment and more skills - also tech diving is a lot about problem solving and fine tuning -i can promise you in 6 months of regular diving youll have it sorted and youll reread your post and smile to yourself

Do you have any suggestions on how they might work this problem and fine tune it?

 

[Scott]

I was fighting so hard to stay balanced side to side that it was nearly impossible to concentrate on anything else.

Without seeing you in the water I'm thinking your rig is too loose. With a rig fitting properly doubles should be more stable than a single. Understand that what fits now will have to be adjusted for a 7mm or drysuit. I always have to do some adjustments between pool and open water.

You might be tasked learning to manage a drysuit and ITT skills at the same time. I'm not your instructor or know what type a diver you are, but I would like to see some drysuit dives before taking on ITT.

Good luck. Be patient and talk with your instructor before you get too frustrated.

 

[NothingClever]

Aaron,

It’s normal to experience buoyancy and trim challenges starting out on a twinset. It’s also normal to feel some frustration that you don’t have the same buoyancy and trim control as you do with your single tank rig.

I think it takes about three solid dives before you gain confidence that you’re on track and learning how to handle twins. I’m sure other divers got it faster or even needed longer (and perhaps you will need a bit more time since you jumped in with beefy tanks) but stick with it.

 

[lermontov]

Do you have any suggestions on how they might work this problem and fine tune it?

i think you and others have covered it well - id just be repeating
id second keeping weights low to lower centre of gravity and put the wet suit on and tighten up straps -