Diving twins with manifold and isolator, but 1 reg?

[John C. Ratliff]

This is what the navy uses.. I think... This video shows a reserve on the manifold..

dumpsterDiver,

Thanks for posting this video. It is interesting to me. If this is the U.S. Navy, they have stopped using the cross-chest strap on their harness. Also, they have moved the lower band further down and don't use a crotch strap. This is much different from when I went through the U.S. Navy School for Underwater Swimmers in 1967. Personally, I don't like that lower band down that low, unless I use the European weight belt buckle and crotch strap design (without a waist strap). With the lower band that low, it is possible for the waist strap and the weight belt to get tangled. Here's a photo of their gear at that time.

SeaRat

 

[charlier]

Putting the cylinders into an isolated manifold is a way of creating 'one big tank'. However, with only one 1st stage used, there are no benefits from redundancy. There are also hazards (hence the advice on blanking plugs).

To reap the true benefits of double tanks, it is a simple matter of buying a second 1st stage and splitting the 2nd stages on each regulator. You don't need an extra SPG, LPI.or different hoses.

I agree with Andy - using an isolated manifold with only one 1st stage gives you no benefits for redundancy. My personal feeling is keep your kit simple with a proven track record. Purchase an extra 1st stage with long/short hose and be done with your kit - similar to a technical backmount twin set up.

 

[Bob DBF]

I agree with Andy - using an isolated manifold with only one 1st stage gives you no benefits for redundancy. My personal feeling is keep your kit simple with a proven track record. Purchase an extra 1st stage with long/short hose and be done with your kit - similar to a technical backmount twin set up.

Well to be honest, the surface was the redundancy I was trained to trust. I dove, and still dive, single post manifolds. If I want redundancy I dive with a pony/stage of whatever size I feel I need. As for a proven track record, isolation manifolds will have to be on the market longer to be proven more reliable over time than single post manifolds which are still used by the U.S. Navy because of their reliability.

I do not argue that isolation manifolds are desirable when needed for conservation of gas by a highly trained user.

I agree that having isolation manifolds with dual regs in the hands of a competent operator is more redundant than a single post manifold with a single reg, however reliability is another issue altogether.



Bob
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Until they invented Tech divers, I used to be one.