i WAS WONDERING IF ANY OF YOU COULD GIVE ME SOME INFO WITH INDEPENDENT TWINS. I AM INTRESTED IN GETTING INTO DOUBLES AND I HAVE TALKED WITH A FEW PEOPLE AND THEY SEEM TO LIKE THE INDEPENDENT TWINS SETUP. ANY HELP WOULD BE GREAT THANKS.
Independent Twins
- Thread starter DudleyNMU
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H2Andy
Contributor
hey dudley, welcome aboard
just fyi, people will give you grief if you write in all caps
just fyi, people will give you grief if you write in all caps
Independent doubles take a complex set up and make it more complex. Many would add, 'more complex than it needs to be'.
Instead of one gas supply contained in two tanks, which can be isolated, with one SPG, one inflator, etc. independent doubles require multiple regulator switches (to keep gas volume in both tanks roughly comparable), tracking psi on two SPGs, and offer a host of 'what ifs' in terms of drysuit inflation, BC inflation, CC SMB/liftbag inflation, etc.
While some will debate the issue, generally speaking simpler is better underwater. If you're starting with doubles, get a manifold. There may be occasions in life where you must use independent doubles out of necessity. I suspect they are rare, however, and your dive planning, gas managment planning, emergency response skills, and many other aspects will be simplified considerably by using a standard set of manifolded doubles.
JMHO. YMMV.
Doc
Instead of one gas supply contained in two tanks, which can be isolated, with one SPG, one inflator, etc. independent doubles require multiple regulator switches (to keep gas volume in both tanks roughly comparable), tracking psi on two SPGs, and offer a host of 'what ifs' in terms of drysuit inflation, BC inflation, CC SMB/liftbag inflation, etc.
While some will debate the issue, generally speaking simpler is better underwater. If you're starting with doubles, get a manifold. There may be occasions in life where you must use independent doubles out of necessity. I suspect they are rare, however, and your dive planning, gas managment planning, emergency response skills, and many other aspects will be simplified considerably by using a standard set of manifolded doubles.
JMHO. YMMV.
Doc
Doc Intrepid:
Yeah real complicated. 2 spgs, drysuit inflator off 1 1st stage bcd inflator off the other for total redundancy. Change regs after 1/3 and 2/3 for a total of 2 reg switches throughout the dive.
The big what if???? If something happens to one side switch regs and abort the dive.
Independants are a very safe and simple way to go.
I don't dive independant myself, buts a lots of my friends do, including Dave. Many times I have study some of the procedures they used and it seem simple and safe enough to me.
All you need to do is a couple of regs switches as mention in Dave post and the only extra equipment needed is one more spg. I know if I was travelling somewhere and cloudn't find a manifold double I would have no problem using independants.
One thing I have notice from some divers decide to dive independants because they don't want to spend money on a manifold. Now to me that the wrong reason to dive indenpendants. But if someone show you the right way to use indenpendants vs manifold doubles go ahead. they are safe and easy to used.
All you need to do is a couple of regs switches as mention in Dave post and the only extra equipment needed is one more spg. I know if I was travelling somewhere and cloudn't find a manifold double I would have no problem using independants.
One thing I have notice from some divers decide to dive independants because they don't want to spend money on a manifold. Now to me that the wrong reason to dive indenpendants. But if someone show you the right way to use indenpendants vs manifold doubles go ahead. they are safe and easy to used.
matt_unique
Guest
wedivebc:
I dive manifolded doubles but independants offer different challenges and safety benefits. I would not consider the process required for independants complicated at all. The great benefit to manifolded doubles is also the Archilles Heel. If, for whatever reason in the world, you cannot shut your isolator in the event of a catastrophic gas loss, you will loose all your air. With independants you need only to change regs and you have (if you have used them properly) half your remaining air safe and sound.
The beauty of a manifold with isolator, and the procedures for manipulating your tank valves, is the ability to access the gas from both tanks if you can isolate a gas loss to one tank and shut down the post.
So....both offer advantages over the other and both pose at least slightly different procedures.
--Matt
I dated a pair of very independent twins... oops, wrong kind. Seriously, I've been giving thought to the same set-up. I'm not a technical diver, but I like the added safety (and, IMHO, simplicity) of independent twins since I dive solo most of the time. I already carry a 13 cf pony with its own reg, so I don't see this setup being much different except in terms of weight.
wedivebc:
Thats two reg switches that must be made using independent doubles that need not be made if using a manifold.
That's "more complex".
Start carrying two deco bottles, get involved with some unscheduled excitement, and that requirement adds task loading. Added task loading is seldom a desirable benefit from any equipment configuration.
Depending on what sort of dive it is, e.g. whether you're in an overhead environment, whether you've staged bottles, or you've built up a deco obligation, if something happens to one side you may not have access to any of the remaining gas on that one side.wedivebc:
If something happens on one side to a set of manifolded doubles, you generally still have access to the entire quantity of backgas through the other post. Depending on where you are when you have the problem, what sort of dive you're doing, you might need access to all your remaining backgas.
That's clearly your opinion and you're welcome to it. In my opinion for technical diving independent doubles are a convoluted cluster that belong in the same category as stuffing the long hose, head slates, and duct-taping your argon bottle to your tank valve.wedivebc:
Dive safe,
Doc
Hoosier
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I dive with independent set up occasionally. Actually, I got the independent idea from many members in this board, for example DA Aquamaster. I became an aficionado after trying once. The main benefit in the independent set up is its flexibility. You dont need to sacrifice two tanks only for the double set up. Wherever you go with double travel band, you can set up the double within 5 min. I am not sure how many charters allow you to set up the double with your own manifold. Another benefit is to have a redundant air source like a pony bottle. Each tank can be act as a redundant air source.
As for the complexity, I am not sure why some people argue that it is a complicated set up. Only thing you have to know is a gas management, 1/3 the first, 2/3 second. No matter what double set up you have, you need to have two regulators. Yes, you need to have one more mini SPG. Is it a big deal to have one more SPG?
Otherwise, how do you think about the tech diving set up (Primary double, two deco tanks, and one argon tank)? It looks like a tank delivery guy to me.
Of course, I am not a tech diver yet, but I can say about the independent double based on my experience. My 2 cents.
As for the complexity, I am not sure why some people argue that it is a complicated set up. Only thing you have to know is a gas management, 1/3 the first, 2/3 second. No matter what double set up you have, you need to have two regulators. Yes, you need to have one more mini SPG. Is it a big deal to have one more SPG?
Otherwise, how do you think about the tech diving set up (Primary double, two deco tanks, and one argon tank)? It looks like a tank delivery guy to me.
Of course, I am not a tech diver yet, but I can say about the independent double based on my experience. My 2 cents.
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