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

[W W Meixner]

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...

Aaron...

I'm currently diving with double 117's...your problem is less likely to do with your cylinders...and more likely to do with your hogarthian BP/H/ assembly...

For me...open/uncovered back-plates are extremely uncomfortable...I've always sworn by an OMS IQ Pack comfort harness...the back-plate slips into a back pocket in the jacket/harness...which is fully padded...you can cinch it up snug...it stays put...and remains comfortable...as well...I've always preferred to have a system with a quick release chest strap...makes a world of difference in keeping your harness shoulder straps stable...

Hogarthian systems once set up have only waist cinching...the OMS IQ pack has waist/each shoulder/chest cinching...so whether you're diving in trunks...or a full cold water/weather drysuit...you can fully adjust the four point harness...five points with crotch strap...quickly and easily each time you suit up...

Try some harness options...I think you'll find I'm correct...You'd have the same problem you're having now with HP steel 80/100 doubles if your harness allows movement of your kit...

As far as ballast...I dive with a dry-suit full time...no ballast...OMS aluminium back-plate...

Stabilize your cylinders and you'll be able to do barrel rolls/somersaults...with no problems...

If you have quick easy pool access...practice as much as time will allow...you'll pick it up quickly...

Best of luck with your new doubles...

W.W...

 

[PfcAJ]

Aaron...

I'm currently diving with double 117's...your problem is less likely to do with your cylinders...and more likely to do with your hogarthian BP/H/ assembly...

For me...open/uncovered back-plates are extremely uncomfortable...I've always sworn by an OMS IQ Pack comfort harness...the back-plate slips into a back pocket in the jacket/harness...which is fully padded...you can cinch it up snug...it stays put...and remains comfortable...as well...I've always preferred to have a system with a quick release chest strap...makes a world of difference in keeping your harness shoulder straps stable...

Hogarthian systems once set up have only waist cinching...the OMS IQ pack has waist/each shoulder/chest cinching...so whether you're diving in trunks...or a full cold water/weather drysuit...you can fully adjust the four point harness...five points with crotch strap...quickly and easily each time you suit up...

Try some harness options...I think you'll find I'm correct...You'd have the same problem you're having now with HP steel 80/100 doubles if your harness allows movement of your kit...

As far as ballast...I dive with a dry-suit full time...no ballast...OMS aluminium back-plate...

Stabilize your cylinders and you'll be able to do barrel rolls/somersaults...with no problems...

If you have quick easy pool access...practice as much as time will allow...you'll pick it up quickly...

Best of luck with your new doubles...

W.W...

Ellipses

 

[Aaron Harmon]

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.

.

My instructor felt that once in my the dry suit, things will be different as well. My thought was it's adding another piece of unfamiliar equipment. Should I go wright into drysuit as soon as it arrives and add it to my configuration so that I can begin getting used to it, or should I switch back to a single tank, learn the dry suit and then add the doubles back in?

 

[Aaron Harmon]

Aaron...

I'm currently diving with double 117's...your problem is less likely to do with your cylinders...and more likely to do with your hogarthian BP/H/ assembly...

For me...open/uncovered back-plates are extremely uncomfortable...I've always sworn by an OMS IQ Pack comfort harness...the back-plate slips into a back pocket in the jacket/harness...which is fully padded...you can cinch it up snug...it stays put...and remains comfortable...as well...I've always preferred to have a system with a quick release chest strap...makes a world of difference in keeping your harness shoulder straps stable...

Hogarthian systems once set up have only waist cinching...the OMS IQ pack has waist/each shoulder/chest cinching...so whether you're diving in trunks...or a full cold water/weather drysuit...you can fully adjust the four point harness...five points with crotch strap...quickly and easily each time you suit up...

Try some harness options...I think you'll find I'm correct...You'd have the same problem you're having now with HP steel 80/100 doubles if your harness allows movement of your kit...

As far as ballast...I dive with a dry-suit full time...no ballast...OMS aluminium back-plate...

Stabilize your cylinders and you'll be able to do barrel rolls/somersaults...with no problems...

If you have quick easy pool access...practice as much as time will allow...you'll pick it up quickly...

Best of luck with your new doubles...

W.W...

I thought about hooking my back plate and wing to an Apeks WTX harness. My instructor said that was how he learned and he regrets not going to the Hogarthian set up right off the bat. I imagine when I done with these 3 classes I can try to figure out what will work for me moving forward. He feels learning this rig those is a fundamental skill.

 

[Aaron Harmon]

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

Keep us posted.

I'm going to work on this...

 

[Aaron Harmon]

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.

Yes this was what my instructor told me...

 

[Aaron Harmon]

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

Thanks

 

[CAPTAIN SINBAD]

Those HP-117s are my favorites for diving doubles. Once the harness has been adjusted to your body, they should not wobble around as much. Still, going from AL-80 to steel doubles and those also 117's is like driving a Toyota Prius all your life and then sitting in a 10-wheeler and taking it for a drive. In the beginning you will feel like the tank is taking you but after some time (and possibly a few adjustments with your harness) it should become a natural extension of your body. It is a jot of fun so enjoy the learning curve. Soon you will be flying with those things on your back and you will want to remember this time.

 

[decompression]

You have a choice which will depend on you......
1) dive a single and get used to the drysuit.....should happen fairly easily but will take time away from ITT training
2) add doubles to drysuit......will be extremely frustrating trying to manage a drysuit and doubles but advantage is you won’t have to transition from single to doubles

So, if you can work through the challenge of drysuit/doubles that will speed up the process.

 

[macado]

To be perfectly honest double HP117s are absolutely beasts of tank system without a wearing drysuit or thick wetsuit. Personally I would not use these tanks with a wetsuit but that's another debate all together..

My suggestion for you with your harness is to make sure your crotch strap and waist straps are tight. Both of these will help stabilize the rig on your back. Believe it or not, shoulder straps can be a lot looser than most people realize.

Does anyone have a set of double AL80s or LP85s you can try to at least get used to having doubles on your back? You can learn how to use doubles and do value drills with a smaller set of doubles. HP117s are REALLY heavy without wearing any exposure protection. That's just a really sh*tty* setup to dive in a pool with just a bathing suit.

I suggest wearing a full 5mm or 7mm wetsuit (these won't compress too much in a pool environment, using an AL plate, anything to make that setup more manageable..