My steel doubles and wetsuit - no mix?

[scuba hamster]

Hello,

I have a question. I have just started my technical class and got myself a set of doubles - steel 120's plus steel plate and OMS single wing. Once in water, I noticed that I need no weight whatsoever, even when wearing my dry suit. Now the question - does it mean that I can't use doubles with wetsuit? The concern is that if I puncture my wing, I won't be able to establish a positive/neutral buyoncy at depth and hence going to sink like a rock. With dry suit, I can put extra air in it, but with wetsuit I am pretty much screwed. Anybody has the same concern? I don't really want to spend $500 for dual wing and I don't think that alluminum plate would make much of the difference

Thanks a lot

 

[sea2summit]

This will be covered in your class. This is why it's good to take a class prior to jumping with doubles. Boils down to redundancy and options with the final choice being left to the diver.

 

[ptyx]

I never dove doubles (but I did the math), so caveat emptor...

You're looking at about 18lbs of air in your tanks (if my math is correct), so that's 18lbs to overcome in case of BC failure at the end of the dive.

At depth, add 8-10lbs of extra loss due to wetsuit compression (ballpark).

And that's if you're 'just right' with no weight, even worse if you're already overweight (I know I would be with your setup).

Total: at least 26lbs to overcome. Not a good idea. And at this point AL won't make much difference. (But AL - and a lift bag - would probably be a good idea with the drysuit anyway).

 

[BabyDuck]

yeah on talking with your instructor, but...

i dove wet with double 95s for a year or so. i satisfied myself that i could swim them up from 20 feet (because since i couldn't hold a stop, i didn't want to barrel up from deeper even though i would if it were a choice of bent or dead...anyway...)

and, yeah, i could do it. i had a big lift bag as another 'just-in-case' and didn't worry about it. the al plate would make several pounds of difference which might or might not tip things into more favorable balance for you.

 

[scuba hamster]

Thanks for all the replies. I guess that for now, I will be using doubles exclusively with my dry suit and will keep my lift bag handy. Here, in North East cold water, wearing a dry suit is pretty much common option for ocean dives. I asked this question, because in a late summer, I like diving wet in the local quarry and this is where I get my training including doubles.

 

[Belmont]

If your wing has bungee cords compressing it you should remove them. There won't be much air left in it if it ever gets punctured or your exhaust valve fails.

 

[Colliam7]

I have just started my technical class and got myself a set of doubles - steel 120's plus steel plate and OMS single wing. Once in water, I noticed that I need no weight whatsoever, even when wearing my dry suit. Now the question - does it mean that I can't use doubles with wetsuit?

Not at all! I use double steel 120s with a wetsuit, without difficulty.

The concern is that if I puncture my wing, I won't be able to establish a positive/neutral buyoncy at depth and hence going to sink like a rock. With dry suit, I can put extra air in it, but with wetsuit I am pretty much screwed. Anybody has the same caoncern?

The 'standard' recommendation with diving doubles wet is to have a dual bladder wing. And, I frequently use one in that configuration. But, it is also possible / practical / reasonable to simply carry another redundant buoyancy source - a lift bag, a SMB, etc.

I don't really want to spend $500 for dual wing and I don't think that alluminum plate would make much of the difference

It wouldn't. While I would suggest that a dual bladder wing is probably the best, or at least the simplest, solution, there are other options for redundant buoyancy that will work well. Also, I do use an AL backplate when diving steel doubles wet, and would recommend that as a 'usual and customary' practice, it is not required.

 

[spacemanspiff1974]

My IANTD intro to tech instructor told our class that we needed redundant buoyancy. This could be in the form of a drysuit or a dual bladder wing. Another instructor I spoke with in Cozumel told me that you only need redundant buoyancy if you can't swim all of your equipment up with a wetsuit only.

While I can swim my gear up with no air in my wing, I'm personally happy that I have a dual bladder that I have never needed. Holding steady on a deep stop with no smb deployed, no mooring line and no buoyancy would be a PITA. Sure, one could use a lift bag, but is it easier than a dual bladder wing?

 

[lowridersvt]

Well rule of thumb is that we dive what you can swim to the surface with no air in your wing with out using anything as redundant boyency. For most people that is a aluminum tanks and a aluminum plate .Idea is that lift bags are good and its doable but not from great depth. and if you wing fails from a puncture the second bladder will most likly fail also. And the chance of your drysuit inflation and you wing failing are slim to none since you run them off your sperate posts of your doubles or use an argon set up for suit inflation

I dive steel tanks with a wet suit but only steel 98's since im a big guy need allot of weight its like a normal person diving al80's .

So the only rite way to dive steel tanks is with a dry suit and a single blader wing

 

[Big-L]

I completely disagree. Who made this "rule of thumb" you’re talking about?

First of all, the ballistic material used in the outer shell of bladders (and even the inner shell) are equal or more resilient as the material used in dry suit. Due to the continuous construction of BCD’s I actually believe that there are more fail points in a dry suit than a BCD. Inflation device, purge valves, neck and arm seals, etc…

Running your dry suit off a separate post than your inflator gives no more added redundancy than a dual bladder. Both inflators have their own hoses which should be run off separate posts. You would leave your 2nd inflator hose disconnected unless there is an emergency to make sure you don‘t accidentally put air in it. I understand that this is extremely task loading for all levels of diving but in the event of an emergency, connect the secondary inflator hose and voila! You don’t even need to balance air between your dry suit and bladder!

Remember people we're talking worst case scenarios. Should both your inflation devices fail (and your third if you have a lift bag) then look to your buddy, signal, call the dive and return to the surface safely. He is your third (or fourth) redundancy. If you don’t have a buddy (I don’t condemn solo diving because this is an avenue I am pursuing) then your original dive plan SHOULD have taken into consideration the unlikely event that you would have to swim to the surface. Swims are in the OW and DM curriculum in order to ensure that you are fit to dive… and if you’re at 300 ft. depths alone then I’m sorry but you’re SOL.

I'm a wetsuit diver, always will be (perhaps a dry suit one day, because I would like to learn all aspects of scuba diving), I dive with heavy steel tanks, single or doubles and/or stage bottles because I like having lots of air and a back-up if needed. If you are unable to be positively buoyant without ditch-able weight, you need a redundant buoyancy device and I would highly recommend a dual bladder regardless of your exposure suit.

Can you ever REALLY be safe enough?