Question Turn a single bladder rig into Dual Bladder

[macado]

For what it's worth most people can swim up ~10-15lbs easily. You also have to consider this is at the very extreme end of having full gas in both cylinders.

A failed wing in most cases will probably still trap some air/gas. Also as you ascend your wetsuit will gain a bit of buoyancy.

If you are worried try swimming up with zero gas in your wing. You might be surprised. I recommend everyone at least try to swim up the rig they're diving in.

 

[jstotz]

For what it's worth most people can swim up ~10-15lbs easily. You also have to consider this is at the very extreme end of having zero gas in both cylinders.

A failed wing in most cases will probably still trap some air/gas. Also as you ascent your wetsuit will gain a bit of buoyancy.

If you are worried try swimming up with zero gas in your wing. You might be surprised. I recommend everyone at least try to swim up the rig they're diving in.

Ya know, I'm going to try that next time I get a chance. 12 lbs seems impossibly heavy to me but I admit I've never actually tried with a known weight.

Now there is also the issue of safely staying afloat on the surface of the water once you've made it there.

 

[jstotz]

Your worry is being able swim up a full rig. if you carry the weight of your gas (or less) ditchable, then you mitigate that problem.


You don't need redundant buoyancy if you balance your rig. That 12-14lb range is also usually what is generally considered the upper range of weight the average person can swim up.

I'd say more, but you seem pretty sold on buying the dual bladder wing.

Not precisely. I am a dual bladder advocate (when drysuits aren't in use). I'm sold on buying a discounted single bladder wing, as long as it's feasible to modify it into a dual bladder. I'm thinking it could be done. Will post pictures if/when successful. If nothing else y'all can tell me how I've got far too much time on my hands!

 

[Still Kicking]

Not precisely. I am a dual bladder advocate (when drysuits aren't in use). I'm sold on buying a discounted single bladder wing, as long as it's feasible to modify it into a dual bladder. I'm thinking it could be done. Will post pictures if/when successful. If nothing else y'all can tell me how I've got far too much time on my hands!

Sorry but you can't modify a single into a dual. If you are convinced you need a dual bladder (unnecessary IMO) buy one and enjoy it.

Extended range diving is no time to be cheap.

 

[rjack321]

I appreciate my one and only response on this .... baht:

Let's assume you're diving two aluminum 80's and first you try weighting yourself to be neutrally buoyant when both tanks are full. You start breathing your air and you will immediately become positively buoyant.

So obviously, we instead weight ourselves to be neutrally buoyant, when possible, when tanks are empty (at the end of a dive). THEN we add 2 x ~6.5 lbs = 13lbs of compressed air to our tanks.

Therefore, at the beginning of a dive with aluminum doubles, you are *at a minimum* 12-13 lbs "over-weighted", assuming you're weighting yourself properly to avoid an uncontrolled ascent at some point of your dive.

In the case of a bladder failure, while 12lbs negative, I don't know that "swimming up" is a great solution.

I admit I'm not very experienced; perhaps redundant lift in warm water with alu80's is unnecessary for other reasons that I don't understand.

Swimming up 15lbs is ridiculously easy. Try it before you claim it's hard or dangerous

 

[rjack321]

Not precisely. I am a dual bladder advocate (when drysuits aren't in use). I'm sold on buying a discounted single bladder wing, as long as it's feasible to modify it into a dual bladder. I'm thinking it could be done. Will post pictures if/when successful. If nothing else y'all can tell me how I've got far too much time on my hands!

Then buy one ya cheapsake. Typically the price of a replacement bladder is close to the price of a whole new BCD. So unless the new-to-you-used BCD is basically free, it's not going to be cost effective.

 

[jstotz]

Then buy one ya cheapsake. Typically the price of a replacement bladder is close to the price of a whole new BCD. So unless the new-to-you-used BCD is basically free, it's not going to be cost effective.

I have learned to expect and appreciate your curmudgeon responses.

We can't all make rjack321-money. I'm about to save $100 on this sidemount rig and buy a $60 bladder: a cost savings of $40 sir.

That's 2 air fills!

 

[jstotz]

Sorry but you can't modify a single into a dual. If you are convinced you need a dual bladder (unnecessary IMO) buy one and enjoy it.

Extended range diving is no time to be cheap.

I'm going to prove you wrong: Every time is my time to be cheap!

 

[eightytwenty]

Not precisely. I am a dual bladder advocate (when drysuits aren't in use). I'm sold on buying a discounted single bladder wing, as long as it's feasible to modify it into a dual bladder. I'm thinking it could be done. Will post pictures if/when successful. If nothing else y'all can tell me how I've got far too much time on my hands!

I'm not going to argue here. I think you should do that, purely for the sake of everyone else around you. I know for sure that I wouldn't get anywhere near a guy diving a single bladder wing that he stuffed a second bladder and inflator into.

 

[Rob9876]

Out of curiosity do you know what the buoyancy of a fully inflated 6-7ft DSMB would be? My guess is plenty

DSMBs are considered a redundant source of buoyancy for SDI Solo parameters, which is non-technical. I'm sure they would be less than ideal in a technical/overhead setting. According to this page: "for emergency purposes a fully inflated { 6 ft | 1.8 m } tube may be considered to have approximately { 13 lb | 6 kg } of lift when completely submerged."

I guess another option might be to wear the Katana 2 on your back and a Mae West/Horse Collar BCD like this one on the front, though that seems like it would be pretty bulky!