Thoughts on post roll-offs and first stage hose routing

[Tortuga68]

1) Flow checks

I don't know what this means

...the person ahead of you on your long hose...

Is this the current convention for air share exits, OOG diver in front? Why?

On a related point, during a blind exit, at what point do you maintain touch contact, ie arm/thigh etc?

 

[ianr33]

Is this the current convention for air share exits, OOG diver in front?

Absolutely!

If the OOG diver is at the back,stops, due to a restriction or some other reason and the diver with air in front does not notice, then the OOG diver could have the reg pulled from his mouth and be SOL.

 

[Ste Wart]

Disagree.

Check spg before restriction. Lets say its 2900. Go through restriction. Check spg, now 2850. Is the left post still open? No way of knowing unless you check the valve or breathe the backup reg.

Of course,this is just another reason to dive sidemount!

I meant that your buddy has allowed himself to get into an OOA situtation by not checking his SPG frequently. Nothing to with Roll off in this instance.

 

[Tortuga68]

If the OOG diver is at the back,stops, due to a restriction or some other reason and the diver with air in front does not notice, then the OOG diver could have the reg pulled from his mouth and be SOL.

I was thinking the same thing could happen in reverse - but then the OOG diver could stop/go back and the reg should still be there, so that makes sense. Thanks

 

[Tortuga68]

However the scenario is a huge 'what if' IMHO. We're assuming that a cave-diver who is capable of dealing with some seriously tight restrictions has actually been negligent enough to forget to check is SPG.

I meant that your buddy has allowed himself to get into an OOA situtation by not checking his SPG frequently. Nothing to with Roll off in this instance.

Eh, **** happens. Lost line/lost diver, whatever. Better to be rigged to deal with the "what ifs" than not

 

[cool_hardware52]

I don't know what this means

Flow check = checking the status of all your valves, right, iso, left and any stage or deco bottles. Do so routinely, after any contact and after any drills.

Is this the current convention for air share exits, OOG diver in front? Why?

Impaired diver is either leading out or is in the middle of three man team.

Think about what would happen to a OOG diver in last position if they have another problem, like loosing the long hose.


Tobin

 

[Tortuga68]

Flow check = checking the status of all your valves, right, iso, left and any stage or deco bottles. Do so routinely, after any contact and after any drills

Ah, thanks


Anyone want to chime in on the touch coms point?

 

[Cave Diver]

A valid reason, I agree.

However the scenario is a huge 'what if' IMHO. We're assuming that a cave-diver who is capable of dealing with some seriously tight restrictions has actually been negligent enough to forget to check is SPG.

I meant that your buddy has allowed himself to get into an OOA situtation by not checking his SPG frequently. Nothing to with Roll off in this instance.

Not necessarily. Fecal matter happens. An o-ring could blow. They could be diving stages and came back to find an issue with one of the bottles. A reg could freeflow. There could have been an incident delaying the team, or causing one member to have a higher than normal breathing rate. There are many different scenarios that could happen which might cause an OOG exit besides failure to watch gas supply.

Is this the current convention for air share exits, OOG diver in front? Why?

Ian nailed it.

On a related point, during a blind exit, at what point do you maintain touch contact, ie arm/thigh etc

On a blind exit, I'm going to be in touch contact with my buddy.

I was thinking the same thing could happen in reverse - but then the OOG diver could stop/go back and the reg should still be there, so that makes sense. Thanks

An OOG diver is not going to outswim his air source.

 

[ucfdiver]

I have trouble with this belief that you can 'roll off' a valve. This would mean that your buoyancy is shocking that there is so much contact with a cave roof; therefore you should not even be cave diving.
I keep my long hose left. The reason? if it does roll off I'm the first person to know about it.

I've rolled a valve off going through restrictions for extended periods. It can, and will happen to everyone who does this long enough.

FWIW I don't look at my SPG but a few times each dive. If I can't hear air bubbles leaking, there's really no reason to check it. On all but the easiest cave dives, we bring enough gas to get to our destination, so we basically know how far we can get before we have to turn on gas.

 

[Ste Wart]

Not necessarily. Fecal matter happens. An o-ring could blow. They could be diving stages and came back to find an issue with one of the bottles. A reg could freeflow. There could have been an incident delaying the team, or causing one member to have a higher than normal breathing rate. There are many different scenarios that could happen which might cause an OOG exit besides failure to watch gas supply.

Again agreed.

All these things are possible. Then again so is periodically checking for roll-off, surely? So the left post can still be used in Cave-diving if one is so inclined to check for roll off.
It is important to keep skills and awareness high. In keeping with this I will do a valve shutdown every dive or so to make sure I'm refreshed with the procedure. Not practical in a cave environment, but checking the valve is opened fully should be.