The great independents versus isolation manifold debate

[Axeman]

when I dive with twins I am going with indep right now.

This is only due to cost though.
once I save up a few pennies I will get a manifold w/isolators...
the amnifold is very vesatile and there is less work involved in tracking your gas usage.

 

[DA Aquamaster]

The benefits of independent doubles are low cost in terms of manifolds you don't have to buy, increased flexibility, and the ability to use off the shelf rental tanks with your regular configuration when you travel.

And perhaps the biggest advantage is that with a large scale freeflow of one reg (for example in a first stage freeze up) the situation does not jeapordize your entire air supply. Assuming you manage the gas to ensure adequate air in either tank to surface at any piont in the dive, no action is required as it would be to preserve any air in a set of manifolded doubles. You can take action to close the valve, and should, but you won't die if you don't. Personally I have never found the additional gas management task to be particularly demanding.

They are not for everyone, or even a signficant percentage of divers, but for my specific needs they are ideal.

 

[athomson]

Thanks everyone.

 

[Epinephelus]

DA Aquamaster once bubbled...
And perhaps the biggest advantage is that with a large scale freeflow of one reg (for example in a first stage freeze up) the situation does not jeapordize your entire air supply.

If this really concerns you then you can dive with the isolator closed, treat the tanks as independents, and still have access to all the remaining gas by opening the isolator after you've shut down the offending regulator. So this "advantage" is no advantage at all.
The only times I would choose independents over manifolded doubles would be (1) manifolded doubles are not available, or (2) the dive requires sidemount.
E.

 

[DA Aquamaster]

True to a point but only at the expense of an additional valve, additional O-rings and potential failure points. The advantages and risks of an isolator valve are still subject to debate.

 

[Epinephelus]

In my own experience (since the 60's) and in the experience of those divers I know (lots of old farts - and we dove lots of little manifolded doubles in the early days as well as the big ones we're diving now), I know of more than a few unstoppable freeflows.
I know of precisely one manifold failure - and it was a very slow leak - after a set of doubles came all the way from the back of the pickup truck bed and slammed the valves into the front of it during a collision.
Figure your own odds...
Non-availability of a manifold could be due to expense, so that's valid.
E.

 

[Compressor]

Manifold is the way to go in tech diving. Do and learn what the experts do.

 

[athomson]

Thanks for all the responses!

Tried Manifolded and wings on a few dives recently topping off with a 50m wall dive.

Definitelty the way to go!

Andy

 

[100days-a-year]

Manifolds run anywhere from US$120 to US$180 and up.Compare that to $100+fins,$60 mask,$200-$2000 for wetsuit or drysuit,$700-$2000 for 2 main regs and $400-$800 for 2 stage regs,mix class can go to $1800.What was that about cost?For sidemount caves or someone with a disability I have no problem with independents,to dive them just to thumb your nose at conventional WISDOM is silly to me.Over the years my configuration has changed mostly due to experience dictating common sense solutions.Not that equipment has changed greatly but how to put all that stuff together in a simple,straightforward manner.Glad, athomson ,to hear of your experiences and glad you liked them.Good luck on the mix class.

 

[jumbo]

Im looking for opinions concerning rigging a back plate with independant doubles vs. isolation manifolds; the way I understand it there is a ressurgance of divers perfering independant cylinders citing problems with manifolds such as roll off, entanglment, more points of failure, if any of ya'll have opinions I would appriciate them,