No Octo while diving with redundant air supply

[Norwegian Cave Diver]

Lets think about a SM configuration for a few moments... Two independent first stages and two regulators (one per first stage). No reason to add a second regulator. My right tank has a 7' long hose that has a bolt snap very near the regulator - all that goes under my right arm - across my chest - over my left shoulder - across my neck - and will be adjusted to be just long enough for me to breath from it or clip it off to my right shoulder d ring when not in use. Full view of the pressure gauges and valves. Now when I add a stage it hangs from my left chest D ring and a Left D ring on my waist belt (Halcyon Eclipse).
Now take that thinking and adapt it to back mount single tank diving.
Back mount gas has its own pressure gauge and IF you sling a 40 cf stage from the front as I described above... then you have two independent sources of gas/hoses/regulators/pressure gauges.
The question now becomes... do I breathe from the stage during a dive? You should... on the surface test breathe both regulators to know they breathe easy and dry. If there was a failure of your back mount gas at depth then you have a 40 cf full to take you to the surface and to your SS. If your buddy needed gas then you could donate your stage but... Your buddy will most likely not be trained and therefore comfortable with that stage/task loading. If your back mount long hose is long enough then you keep both tanks and donate your back mount regulator - Just like you have been trained as an OW diver.

 

[johndiver999]

Why would I do something that might give me a lung infection?

If you empty the bladder when you try it, this is not an issue. Might be a useful trick when plan c fails and the last thing you are worried about is a lung infection. I’ve sucked air out of bc’s prior to a dive literally 100’s of times and I never, ever disinfect the bladder and never noticed any problem, so I have to assume the actual risk is low. Gotta look better inside than the inside of some of the bongs I have hit over the years.

 

[johndiver999]

Maybe you should let the OP answer the questions presented instead of assuming it‘s your position to determine what is or is not relevant to their situation. The question of removing a secondary off of the main cylinder has nothing to do with where the bailout is mounted. It’s about removing a regulator that the OP feels may not be needed or is removing something that the OP identified as being ”in the way”.

You are mistaken. Where the pony bottle is mounted has everything to do with this. A slung bottle with the second stage bungled to the small bottle will never, ever be confused with the primary reg. Apparently you are missing the very real danger associated with second stage confusion that arises exclusively from the use of back mounted ponies.

 

[Norwegian Cave Diver]

The pony/stage MUST be mounted in the front. This gives you full visibility of the tank/valve/hose/regulator/pressure gauge and allows the complete unit to be transferred to someone.

 

[johndiver999]

The pony/stage MUST be mounted in the front. This gives you full visibility of the tank/valve/hose/regulator/pressure gauge and allows the complete unit to be transferred to someone.

Who says MUST and who enforces that? The Op very clearly stated what he was doing.

 

[DAJ]

You are mistaken. Where the pony bottle is mounted has everything to do with this. A slung bottle with the second stage bungled to the small bottle will never, ever be confused with the primary reg. Apparently you are missing the very real danger associated with second stage confusion that arises exclusively from the use of back mounted ponies.

Again, the OP is asking about whether or not the secondary reg could be removed as it may not be needed. It’s not about where you think it should be mounted or how you might confuse one reg for another. The OP is not asking about location, only the removal of a regulator. I did not see any question as to where a bail-out should be carried. The OP has already stated that they run a back-mount bailout. That’s fine, their gear and their choice. If you don’t like a back-mount, fine don’t use one. The only “real danger” for this setup is directly related to the diver that is using it and the experience they have with that configuration.

 

[rhwestfall]

Let me go back to a fundamental question.... What did your instruction in SOLO (self sufficient) cover or discuss? What is your take on what was discussed?

How do you feel regarding SOLO diving, or being equipped to address a situation dealing with another diver (or a failure in your system)? This is about how you perceive the situation, not what everyone else (educated/trained or not) thinks...

 

[Norwegian Cave Diver]

Sure glad you're not your my diving instructor.

I configure my gear however the hell I want to.

And it's not your way.

Read why it should be in the front and then give reasons why in the back is better?

 

[KenE]

Read why it should be in the front and then give reasons why in the back is better?

Really doesn't matter, OP says he is back mounted. Question is about whether a third second stage is needed, can we please stay on topic.

My answer to OP: it depends on if you want access to the remaining gas in your primary cylinder upon primary second stage failure. If not, no, if so, then yes.

 

[Norwegian Cave Diver]

Really doesn't matter, OP says he is back mounted. Question is about whether a third second stage is needed, can we please stay on topic.

My answer to OP: it depends on if you want access to the remaining gas in your primary cylinder upon primary second stage failure. If not, no, if so, then yes.

I am on topic.
When on back mount single tank - and you want a second independent source of gas - where should that gas be? Front or back? Front stage/pony is far more versatile.