Changing air source using Quick disconnect underwater

[Aanderson81]

I have an Ocean reef FFM with the quick disconnect. I just picked up a pony bottle and was thinking I would get another quick disconnect hose for this and if ever needed i would swap hoses to swap the air source. Obviously I would like to practice this. The question I has was would swapping the air sources in this manner cause any issues with the regulator. I would assume there would be some water likely forced through it. I assume it shouldnt be of a large enough quantity to really cause any issues, but figured I would ask before going down this path.

 

[eelnoraa]

No, you won't have issue with the regulators. BUT a lot more important aspect is to consider why you need to swap to begin with. When you need to swap source, it is because you are having issue breathing. You really won't have time to fish out the hose from your pony, discount the primary source, reconnect the FFM to the pony, turn it on and then you can breath. It mays sound manageable on land, planned. But when this happens under water unplanned, it will be a lot harder.

 

[Aanderson81]

No, you won't have issue with the regulators. BUT a lot more important aspect is to consider why you need to swap to begin with. When you need to swap source, it is because you are having issue breathing. You really won't have time to fish out the hose from your pony, discount the primary source, reconnect the FFM to the pony, turn it on and then you can breath. It mays sound management on land, planned. But when this happen under water unplanned, it will be a lot header.

I dont see any reason why I wouldn't make sure the pony would be on before starting the dive. I am hoping that I can route and clip the hose where its easily accessible and I would like to practice with it. I dont plan on ditching the safe second from the bottle so it would still be available as well.

This is one of those things I never plan on needing. But there are some dives that I would feel more comfortable having a pony bottle and it seems like this would be a more efficient use of the equipment that I have in my setup. I have practiced and continue to practice taking off the FFM and going to my safe second and secondary mask. But it seems like in an out of air situation this could be a more efficient method of switching to the pony given the full face mask.

 

[jbuck88]

Sounds like that is the same way commercial divers use a pony bottle.

They have it charged with a quick connect to swap out

 

[jbuck88]

Edit. Maybe not all commercial divers. But the ones I've seen using surface supplied air.

 

[davehicks]

I have had more than one quick disconnect jam up and fail on me out of the water. I would not want to rely on or plan to use one underwater to access breathing gas. Probably not an ideal setup.

 

[Aanderson81]

I have had more than one quick disconnect jam up and fail on me out of the water. I would not want to rely on or plan to use one underwater to access breathing gas. Probably not an ideal setup.

I acknowledge that this is a point of failure. However this quick connect is specifically designed and sold for the regulator as a breathing air source so I assume that there is a bit higher tolerances in the manufacturing. This is also why I am not abandoning the safe second.

 

[JohnnyC]

The best option is a switch block with both primary and pony plumbed into it. Use QC6 connectors for adequate flow. If you need to switch gas sources, you turn the selector on the switch block.

OmniSwivel Gas Switch Block

Add some QC6's to that in whatever configuration suits you. It's a pretty common setup for hypoxic dil when rebreather diving.

 

[RainPilot]

It can be done, but should it...

I would connect the pony to the octo port on the FFM and dive with it closed. OOG? Open pony, breathe. Fiddling with a QD while out of gas? One fumble from disaster.

The gas block would definitely be the pro way to do it as Johnny suggests but they aren't cheap. You should already have the second stage adapter that came with the mask, so try the port first.

 

[teknitroxdiver]

Sounds like that is the same way commercial divers use a pony bottle.

They have it charged with a quick connect to swap out

The bailout bottle will have a QD but it's already connected to the emergency valve. All the diver has to do is open the emergency valve on the side of the helmet to switch to the bailout. There's no hose-swapping needed to make the switch.