2nd stage bailout positioning

[JonG1]

I am interested to discuss where people mostly locate their deep or primary bailout 2nd stage and whether this is different if they use a BOV.

Mainly interested in BM configuration and the obvious locations are necklaced, on the bailout as per a regular stage, or clipped to a chest d-ring, unless I have missed obvious permutations.

For those that use a BOV do you consider the risk that the BOV may be compromised by caustic and keep the 2nd stage close or is this a low incidence risk.

 

[tbone1004]

cave diver, so the onboard 3l is NOT used for bailout. If using a bov, the adv/mav/bov are all on a manifold that are fed by the same bottle. Input to that is a QC6 which is fed from either doubles or a sidemount bottle for dilout. If not using a bov, then the "bov" is replaced by a short hose that is on a necklace/suicide strap. BOV preferred for backmount rebreathers/sidewinder, and obviously not practical with sidemount CCR so short hose it is on that. This way I know that whatever is plugged into my rebreather is the same gas that I "bailout" to, and being on a necklace, it's almost as accessible as a BOV. If I change my dil gas for whatever reason, then it's the same for my bailout and I just find it easier to manage.

Whether diving doubles or with sidemount for dilout gas, one bottle will always have a 7' or longer hose in case I have to share gas with someone else. The long hose is stowed in the "normal" place on the right shoulder.

 

[JonG1]

Thanks T Bone do you have concerns about the bottle neck and failure points associated with the QD and manifold, I have just done something similar (BOV and 2nd stage off a manifolded QD) and it was this that prompted the thread.

 

[tbone1004]

@JonG1 If you think about it, the first stage is a LP manifold already so having a solid block of metal that is acting as a manifold isn't really a "failure point" for me. Granted if something on that fails, then you have to plug in another way, but that's no worse than if any of the hoses failed individually.
I would not put a BOV and a 2nd stage on the same manifold though. The way mine is setup, the ADV, MAV, wing inflator, and one regulator *bov or second stage* are on the same manifold and are essentially part of the rebreather since the manifold is screwed directly onto the head.
I keep the long hose up there as well so I can bail out to an independent source if the manifold has a failure on a LP hose. A LP hose failure on the manifold isn't "catastrophic" for the rebreather, it's just annoying. You can always take a breath of dil from the independent regulator and breathe it back into the lung for dil if you have to so it isn't a reason to bail out, just really annoying.
Not sure what you mean by bottle neck, but the flow is not an issue to the second stages.

 

[RainPilot]

I have a 5’ hose leading to a pull-away necklace from a sidemounted bailout. This is if I have a rich gas on me so I do the gas ID before necklacing, that way if I have an urgent need I already know which reg is which.

If it’s single bailout or OC buddies then I treat it like a stage tank. Note, I am not diving overhead environments and I have a BOV to onboard to get off the loop fast.

 

[rjack321]

SM my BO
deep is on the left
1st stage has a 12" yellow pigtail with a male QC6 for the BOV on it. (40" hose on the BOV with female end)
6" spg hose routed forward
7ft stuffed long hose, 2nd stage is just forward of my armpit

ps I color code hoses so 1) I can see them against all the other black stuff. 2) tell an OC buddy or a DM on a charter to "pass me the yellow hose" or blue, green etc. when its trapped behind me or just being a pain.

 

[JonG1]

Does anyone else use this set up or have opinions on it.

Basically a MF fed by both dil and offboard, MF feeds ADV, BOV, wing so tank valve isolates un-used cylinder, allows easy switching between an hypoxic dil and safe BO, and depending on depth and dil inc vol of BO available via BOV.

Just seems a little complicated and inc potential failure points.

 

[tbone1004]

@JonG1 It's a pretty standard system, he just has the one extra hose to be able to plug in offboard. It's similar to the way mine is setup. Mine doesn't have the onboard bottles hard lined, so you can only ever have one bottle plugged in at a time which I am a much bigger fan of. The only way to know if you have shut that bottle off, is to shut it off, breathe it down and check the SPG, then plug in and make sure it doesn't change. That to me is more complicated than just plugging it in, then unplugging it if you change your dil bottle. Frankly that is one of the many reasons why I don't use the onboard 2l/3l for diluent, only inflation.

 

[Stevegriscti]

Stowed away with the tank or round the neck like a long hose. All hoses on BO tanks are 90-100cm (36in?) length.

If only one bottom BO many times the 2nd stage is around the neck.

If there's more than one (hypoxic, normoxic, etc) 2nd stage stays on the tank and switch to it after having switched to bov. Yes, the 3l dil will not last a lifetime, but it will last until you get the 2nd stage you want. That said, you should be able to find the 2nd stage quickly when blind/no viz/stressed,etc in any case

 

[RainPilot]

My concern with the distribution block that Achim describes is that one hose failure can lead to loss of all the gas to the BOV (if the hose from the dil 1st stage to the block bursts, then even closing the dil will not stop the off board from emptying through it).

Obviously you can disconnect and use the second stage on the BO tank but that kind of defeats the object IMO. A switch block that isolates the gas would be a better bet in that scenario for me.