Why use doubles?

Please register or login

Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.

Benefits of registering include

  • Ability to post and comment on topics and discussions.
  • A Free photo gallery to share your dive photos with the world.
  • You can make this box go away

Joining is quick and easy. Log in or Register now!

El Orans

ScubaBoard Supporter
ScubaBoard Supporter
Messages
16,452
Reaction score
44
Location
The Netherlands
# of dives
500 - 999
If a set of doubles contains the same volume of gas as a single tank with the following set-up, what would be the DIR reason to use doubles?

singletankrouting1.jpg
 
You do not have true redundancy there. If the tank neck O-ring were to extrude, your entire gas supply is compromised.
 
If each tank were filled identically,a single wouldn't have the same volume of gas as doubles of the same size.
 
Redundancy and stability.
I find that my stability is a lot better when I dive a drysuit than my regular wetsuit.

Since this set-up is not meant for overhead diving, I feel comfortable not using doubles.

If each tank were filled identically,a single wouldn't have the same volume of gas as doubles of the same size.
15L or 2x7L would be quite comparable.
 
If a set of doubles contains the same volume of gas as a single tank with the following set-up, what would be the DIR reason to use doubles?

FIRST: your question contains a faulty premise by specifying "a set of doubles containing the same volume as a single tank" unless you're talking about a set of AL40's doubled up.

SECOND: An H-valve is only redundant from a reg-failure standpoint. It merely provides redundant ACCESS to the relatively small volume of gas contained in a single tank. It does not provide a redundant gas SUPPLY that doubles offer in a situation requiring air-sharing. Particularly important in overhead dives, including deco.
 
SECOND: An H-valve is only redundant from a reg-failure standpoint. It merely provides redundant ACCESS to the relatively small volume of gas contained in a single tank. It does not provide a redundant gas SUPPLY that doubles offer in a situation requiring air-sharing. Particularly important in overhead dives, including deco.

Take a closer look at the pic. That's not a H.

Edit: ehm... yes it is.
 
FIRST: your question contains a faulty premise by specifying "a set of doubles containing the same volume as a single tank" unless you're talking about a set of AL40's doubled up.
I specifically wanted to exclude the argument "to carry more gas".

If I were to use a set of doubles locally, I'd use 2x7L, 2x12L is too much for my current purpose.
 
https://www.shearwater.com/products/teric/
http://cavediveflorida.com/Rum_House.htm

Back
Top Bottom