Reduntant cell or not!

[Tamas]

I have been thinking of getting a proper OMS BP/W setup and wanted some opinions on the setup. Eventually I want to get into some double tanks as well as some more serious techy stuff, so I wanted to start off the gear selection on the right foot.
Should I get a single 65lb cell or go with redundant 65's? Will the 65's eve be large enough to lift/hold/control with doubles and stage bottles and what not or should I even go up to 100 redundant? Overkill? Worth it?
Are there any instances when a 65 is not enough and a 100 is needed? Are there any certifying bodies for tech certs where they have requirements as such?

Suggestions? Comments?

 

[Tamas]

'ello? anyone?

 

[theskull]

By the time you're diving doubles you'll probably be in a dry suit, and that takes care of your redundant lift. In a single you don't need it because you can swim up.

A wing for a single tank should be in the 36-65 lb lift range. It will not fit around doubles.

A wing for doubles (and stages) should be in the 65-80 lb lift range. It will not fit well around a single tank.

You can use the same Backplate and harness for both wings and types of tanks.

theskull

 

[fdog]

Aqua Ho, I dive wet, and use dual bladder Rec wings (about 50 lbs). These have been more than adequate for me for most combinations of doubles. It's at the verge of too big for singles, though.

100 lbs of lift, OMG. That is a whopping amount of lift. Huge. It's overkill for me, but maybe some of the North East wreck diver types will chime in with what their needs dictate.

I use dual bladders because of the wetsuit; you can find plenty of opinions about this. Most that dive dry use the drysuit as the redundant source of lift and use single bladders.

Diving dual bladders has extra task loads that single bladders do not. Make really sure you need dual before traveling down that road.

All the best, James

 

[kramynot2000]

Boy this is a topic with a lot of opinions.

I think all agree on redundancy but there is disagreement on whether it should be another bladder, your drysuit, or even a liftbag.

As for me, I dive dry and use a dual bladder wing for the tech stuff. Before I bought the wing, I tried to use my drysuit for bouyancy control to bring me up from 20' with a set of steel doubles and it was extremely difficult because of all the air I had to put in the drysuit and air started burping out the neck seal. Holding deco stops would be a challenge if I had to. Another buddy of mine tried this as well at 60' and couldn't get off the bottom. There was just not enough lift before the air started burping out the neck seal and this was with steel 80's and 85's. I know there is no way I could use the drysuit for redudancy wearing my 95's and/or full deco bottles especially larger bottles like AL80s.

The theory you'll hear is that you should have a balanced rig and be able to swim up your doubles at 500 psi and also use your drysuit for emergency bouyancy. Although I've asked around, I've found very few who have actually tested this which is why I decided to try.

My recommendation is to slap those doubles on your back and go out and simulate a bladder failure. If your drysuit can lift you, great. Some people are more boyuant than others and some drysuits have more lift than others. If not, I'd look into the dual bladders.

FWIW, I've had no problems at all with the extra bladder and find its really not an issue having another inflator.

 

[NEWreckDiver]

I personally dive 100lb wing dual bladder. If you try, you will find that you will not be able to use your dry suit for buoyancy. This is the reason for the dual bladder.

With the 100lb lift wing, it will work for me no matter what configuration I dive. Just doubles, doubles and 1 deco bottle, doubles and 2 deco bottles, doubles and 2 deco bottles and an argon bottle.

The only exception is for single tanks, I simply don’t use a wing and back plate for single tank diving and I don’t have to worry about it. I still have my BCD for singles.

There is a lot of configuration options you have and you will get 100 opinions from 100 different people, so take this and use want you like and don’t get pressured by other to buy something you are not comfortable with.

Good Luck, DSAO

 

[The Fresh Prince]

I have been thinking of getting a proper OMS BP/W setup and wanted some opinions on the setup. Eventually I want to get into some double tanks as well as some more serious techy stuff, so I wanted to start off the gear selection on the right foot.
Should I get a single 65lb cell or go with redundant 65's? Will the 65's eve be large enough to lift/hold/control with doubles and stage bottles and what not or should I even go up to 100 redundant? Overkill? Worth it?
Are there any instances when a 65 is not enough and a 100 is needed? Are there any certifying bodies for tech certs where they have requirements as such?

Suggestions? Comments?

You are going to get many opinions based on personal preference or comfort level. Many divers overrate the amount of lift needed for technical diving. You can dive double AL 80'2 with a 40# wing. I dive double 104's with a 55# wing, including a scooter, primary light, and three stages and still had more than enough lift. In terms of using your drysuit for additional bouyancy, many divers get vertical during their attempts, causing the air pocket to move to their neck seal, which, being either latex or neoprene, will stretch and release air. If you remain horizontal, a small air pocket in your suit, centered in your back, will serve to provide lift in case of a bladder failure. The same applies to a lift bag, you need to be able to add/release air from it to control bouyancy. Unfortunately, you need to train your emergency protocols to prepare for real life scenarios and many do not. As many technical divers have, we weigh the benefits/deficits of our equipment and decide accordingly. I have decided against a double bladder despite taking all my initial technical training with one. And I use a 55# wing and have dove a 60# and 50# wing.

 

[DutchDown]

Dual bladder wings are pretty popular with my club. There are quite a few tech divers who dive dry and in fresh water using steel doubles and stages. I asked around when I began shopping for a wing and they recommended a dual bladder model. I bought a Dive Rite Dual Rec wing. Seems to me there's no real reason not to have a redundant wing. Runaway inflation? Naw...not likely. Unhook the inflator, just as you would if your drysuit inflator stuck open. Or don't connect the second bladder unless you need it. Redundancy is good. Get some today!

Phil

 

[Hyper-limits]

I use a 60 lbs wing for tech diving and I never had any problem with lift. I also bought myself a smaller wing (32 lbs) for single tank because I like the BP/W set up too much to go back to my old BCD. Most diver have no need for a 100 lbs of lift or double bladder if you are diving with a dry suit.

 

[Tamas]

Thanks for the replies so far. Drysuit is not a problem, would be and will be a must anyways. And I was not even thinking of using it as a lift device. So it is up to the bladder(s) to their job when it comes to control.
What I am trying to see, if there are any requirements when it comes to the technique or any training (agencies, courses) that require a certain size bladder? Any certain techniques that a large 100 bladder is a must? (ie: number of tanks, depth, situation/location, diver size)

I am trying to figure out if I need the large bladder for the extra $$$ or not?