NDL diving with onboard DIL-OUT? Smaller than 40/50's

[flymolo]

Why 2 x 3L, for rec? 1 x 3L is fine and accounts for any single failure.

he's specifically talking about dil-out where your dil+bo are shared. this is mostly done using a set of lp50s or al40s with lolas and a soft manifold

 

[Cio]

he's specifically talking about dil-out where your dil+bo are shared. this is mostly done using a set of lp50s or al40s with lolas and a soft manifold

I know. I'm commenting that 2 x dil-out is not necessary for rec dives, 1 x dil-out is perfectly suited for the job. Any single failure with 1 x dilout still allows an ascent to the surface while breathing something.

 

[mr_v]

I know. I'm commenting that 2 x dil-out is not necessary for rec dives, 1 x dil-out is perfectly suited for the job. Any single failure with 1 x dilout still allows an ascent to the surface while breathing something.

What happens if the loop is severely compromised?

 

[MidOH]

Can't you have a 2nd stage connected to the dil reg?

 

[rjack321]

I know. I'm commenting that 2 x dil-out is not necessary for rec dives, 1 x dil-out is perfectly suited for the job. Any single failure with 1 x dilout still allows an ascent to the surface while breathing something.

Heck why not just go with a 2L at that point? CCR divers trying to bring the absolute minimum BO is like OW divers bragging about how little lead they manage to dive - even if they have to pike dive to get off the surface and float up from safety stops.

 

[flymolo]

I know. I'm commenting that 2 x dil-out is not necessary for rec dives, 1 x dil-out is perfectly suited for the job. Any single failure with 1 x dilout still allows an ascent to the surface while breathing something.

no way man

 

[inquis]

CCR divers trying to bring the absolute minimum BO

Doesn't the minimum vs. plenty BO characterization greatly depend on the specific dive? An assumed 40 L/min rate (throughout) and a safety stop and a minute to get sorted at depth seems pretty conservative. From 60 ft, that's 150 bar from a 3L. Treat that as your Rock Bottom pressure, stay within NDL, and enjoy the dive.

Obviously 1x3L won't work for all rec dives, but if you're targeting the extremely common, multi-level above 60 ft, what's wrong with a lightweight "reef rig"?

 

[Enevoldsen]

My rig - two 6.7l, 300 bar, carbon cylinders and soft Lola manifold, backmouted as DIL-out and a 3l 200 bar, alu for O2.
Always plenty of air for BOV, suit, wing and DIL, and the weight is at a minimum. why take the chances with “just enough” air for bailout? I only to off my dilout when i hit 200 bar = every 3-4 dive….

 

[Cio]

Heck why not just go with a 2L at that point? CCR divers trying to bring the absolute minimum BO is like OW divers bragging about how little lead they manage to dive - even if they have to pike dive to get off the surface and float up from safety stops.

If I was going 60-90 feet, NDL limits, I'd take a 2L. Chances are I could stay on the loop, and if I had to BO, the surface or a buddy is a small amount of BO gas away. Compared to single tank diving, you are less likely to have to swim to the surface. I see this as a slightly more robust equivalent to single cylinder diving.

Fails
O2 cylinder fail - SCR ( feather the bottls maybe) - Plenty of time to surface
Dil cylinder fail. - Stay on loop , thumb dive. hours of time, just cant go down.
Loop loss, unrecoverable flood - BO - BO to 10-13 CF of gas, that's not much but on a reef dive it is plenty to get to the surface.

If I were going deeper, I wood want the 3L

If I am goign to a care free type of dive, being light feels nice, I'll take the lightness and accept that I dive at alevel of safety similar to that of single tank diving which I think most would agree is acceptable.

What happens if the loop is severely compromised?

A 3L is plenty to get to the surface on. This is a rec dive. What single failure leaves you with nothing to breathe to get to the surface? (rec, NDL...)

 

[mr_v]

If I was going 60-90 feet, NDL limits, I'd take a 2L. Chances are I could stay on the loop, and if I had to BO, the surface or a buddy is a small amount of BO gas away. Compared to single tank diving, you are less likely to have to swim to the surface. I see this as a slightly more robust equivalent to single cylinder diving.

Fails
O2 cylinder fail - SCR ( feather the bottls maybe) - Plenty of time to surface
Dil cylinder fail. - Stay on loop , thumb dive. hours of time, just cant go down.
Loop loss, unrecoverable flood - BO - BO to 10-13 CF of gas, that's not much but on a reef dive it is plenty to get to the surface.

If I were going deeper, I wood want the 3L

If I am goign to a care free type of dive, being light feels nice, I'll take the lightness and accept that I dive at alevel of safety similar to that of single tank diving which I think most would agree is acceptable.


A 3L is plenty to get to the surface on. This is a rec dive. What single failure leaves you with nothing to breathe to get to the surface? (rec, NDL...)

What problem are you trying to solve? So far, this reasoning looks like a justification for normalization of deviance.