LP27 (4L) for onboard dil/O2?

[rjack321]

Maybe a cave system with an extreme sawtooth profile?

Hole in the Wall (Mill Pond) will gobble up your dil. 3L probably isnt going to be enough to get to the champagne bottle and back. But you're better off using a smaller O2 bottle, one of your on-boards as suit gas, and offboarding the dil & wing gas.

 

[PEDiver]

It's fairly common to offboard your dil for caving diving and in a backmount unit to use the onboard "dil" cylinder as suit gas (retaining redundant suit vs wing gases).

I've seen that config with the Fathom. SM bailout / offboard dil with the onboard bottle as inflation gas. That setup seems ideal for going the 2L route vs. the 4L.

 

[rjack321]

I've seen that config with the Fathom. SM bailout / offboard dil with the onboard bottle as inflation gas. That setup seems ideal for going the 2L route vs. the 4L.

Fathom, genesis, sidewinder, meg, revo pretty much every backmount unit is friendly to offboarding the dil and, onboarding the suit gas and O2. And avoiding giant 4L dil cylinders.

 

[Snusmumrik]

IMHO.
Large DIL cylinders on backmount unit worsening weight load on your back, unit is going heavy and clumsy.
For me - I've prefer 2-3L onboard DIL and stage-rigged offboard DIL as main source.
I see only one case suitable for large 4L DIL cylinders - rebreather was used by big (7ft tall) well-trained men.
Also - AL cylingers are heavier than steel off water.

 

[Tracy]

I dive them with my optima. I like going to a weekend of diving without needing any additional bottles or fills. It is just another tank, about any of them will work.

 

[PEDiver]

Large DIL cylinders on backmount unit worsening weight load on your back, unit is going heavy and clumsy.
For me - I've prefer 2-3L onboard DIL and stage-rigged offboard DIL as main source.
I see only one case suitable for large 4L DIL cylinders - rebreather was used by big (7ft tall) well-trained men.

I like to think I'm in shape enough to sling the big tanks Luckily I have a buddy willing to loan me a set of 4L bottles to do a try dive with to see how they are. Will be comparing to the 2L bottles.