2nd stage and BOV on same bottle?

[JonG1]

Recently a friend completed his MOD 1 and as part of it a recommendation was made or discussed regarding a particular style of configuration applicable to cave/OHE diving.

Specifically the recommendation was that in the event of having 2 primary, same gas cylinders, with BOV on the left and long hose on the right, you dispense with the standard 2nd stage on the left bottle.
The long hose is then clipped to the right shoulder d-ring (not hog looped though) outside of the loop in a breakaway or bungee loop for ease of self access or deployment.

The idea being a failure point and extra hose is removed and configuration simplified.

I was just interested to canvas opinion.

Currently I retain a standard 2nd stage on the left cylinder, just in case the BOV is affected by caustic or the QD fails, but thought this was an interesting approach.

 

[rddvet]

When I dive with side mounted bailout I do not have a reg on my left bottle. Just a first stage and a qc6 for feeding dil and bov. I was trepidatious about it at first but I discussed it in depth with my instructor and the owner of the ccr brand. I asked what if you need that reg and through lots of discussion it became apparent there was no realistic situation where it would become a problem. A lot of people look at it funny but I’ve yet to have someone argue a point that was a realistic failure scenario where not having the left second stage would become an issue. I do keep a second stage on a qc6 just in case. But I’ve got no issue with no second on the left bottle. People with much more experience than me have thought this out in depth.

 

[grantctobin]

Have done both. Firstly with both a necklaced reg and a BOV, then with a BOV and second stage stored on the bottle, then to only a QC6 male on the bottle. The latter saves having two regs near the neck as well as removing the possibility of catching a stowed second stage on something. I do loop my long hose under my loop when with a CCR only team and this keeps everything tight to my profile.

If you go this route, make sure you add an OPV to the left bottle first stage. The best argument I've seen against the choice of no second stage is lack of OPV reliability. Apeks now makes what anecdotally seems to be a better one and I have not yet had issues with the rebuildable XS Scuba one.

Full disclosure I keep a necklaced second and a DSV in my spares box to be able to switch back if needed (e.g a trip that involves a more even mix of OC SM and SM CCR diving).

 

[rjack321]

Recently a friend completed his MOD 1 and as part of it a recommendation was made or discussed regarding a particular style of configuration applicable to cave/OHE diving.

Specifically the recommendation was that in the event of having 2 primary, same gas cylinders, with BOV on the left and long hose on the right, you dispense with the standard 2nd stage on the left bottle.
The long hose is then clipped to the right shoulder d-ring (not hog looped though) outside of the loop in a breakaway or bungee loop for ease of self access or deployment.

The idea being a failure point and extra hose is removed and configuration simplified.

I was just interested to canvas opinion.

Currently I retain a standard 2nd stage on the left cylinder, just in case the BOV is affected by caustic or the QD fails, but thought this was an interesting approach.

I don't like the idea of my BOV being my sole access to the left bottle. It can be ruined with caustic and even the ISC BOV isnt as nice a breather as a real 2nd stage. The Shrimp definitely has more deadspace and doesnt breath quite as nice as a regular 2nd. The Shrimp also has a very finicky exhaust diaphram which can get goobers in it or just plain fail.

In "cave" configuration I have a stuffed short hose on the left side, long hose right.

In OW configuration where I have a deep BO on the left and 50% on the right, I still have the BOV off the left but the long hose is left sided too. So I can donate that deep BO to a stressed buddy.

 

[lermontov]

Full disclosure I keep a necklaced second and a DSV in my spares box to be able to switch back if needed (e.g a trip that involves a more even mix of OC SM and SM CCR diving).

OC /CCR mixed team is a valid reason - plus if your ccr buddy has a major incident and needs gas -i dont like the idea of having a bottle full of gas i cant access by any other means other than a QD

 

[Smache]

Another option is having the long hose on a QD. That way, if the BOV has a catastrophic failure and cannot be breathed at all, the long hose can be plugged into the left bottle.

This adds a failure point of course, but gives you redundancy without extra clutter around your neck. Worth it?

 

[grantctobin]

Another option is having the long hose on a QD. That way, if the BOV has a catastrophic failure and cannot be breathed at all, the long hose can be plugged into the left bottle.

This adds a failure point of course, but gives you redundancy without extra clutter around your neck. Worth it?

Are you suggesting the long hose on the right bottle have a semi permanent QC6 on it? Who taught this to you?

 

[kensuf]

Ask 2 cave instructors how to mark a jump and get 7 different answers.

I'm in the "I keep a short hose on a necklace bungee regardless of whether or not there's a BOV" when cave diving camp.

 

[berndo]

Another option is having the long hose on a QD. That way, if the BOV has a catastrophic failure and cannot be breathed at all, the long hose can be plugged into the left bottle.

What do you mean? You have the long hose connected to the 1. stage with a QC?
You want to plug the hose into another tank?

Having a necklace and the longhose doesn't really cause clutter around the neck.

 

[Smache]

Are you suggesting the long hose on the right bottle have a semi permanent QC6 on it? Who taught this to you?

That's the idea. I should have clarified, this is not something I've done or even seen being done. Just an idea I had while reading the thread.