Running an RB out of gas

[mkhari]

My plan went wrong as I spent some time on the dive operating SCR and had used basically all the dill - a fact I was blissfully unaware of.

When the time came, I bailed out onto the autoair and got the smallest of breaths - almost nothing. My lungs were empty as I had exhaled whilst coming off the loop.

Lot's of lessons learnt that day.

Sh*t happens mate, at least you got out of it OK. As my instructor told me, always dive with a stage and don't dive with someone who doesn't have a stage. Carrying a stage has stopped an awkward situation for deteriorating twice for me now.

[davydiver]

I dont mean to point out the obvious but all of these minor incidents have been user error, diving with hardly any gas, not switching on cyls etc, things like this are not good to overlook, ccr as we know is a silent killer, theres no substitute for preparation no matter how much bail out gas you take.

[Frodo]

Carrying a stage has stopped an awkward situation for deteriorating twice for me now.

Yep 7l stage now welded to hip and bailout to offboard OC practised.

Once bitten was enough.

[nigelH]

Run out of gas... well nearly

It was a second dive and I hadn't bothered with a fill. I had closed the loop after a prebreathe on the Sentinel and just did the CCR thing and left the mouthpiece in my mouth. Then we had a big delay...

I got to about six meters, solo, looked at the gauges and thought "That's not much!??". Then I remembered they were 2L cylinders now and called it.

I had plenty of O2 and enough DIL for the descent plus I inflate the suit from a separate can so I could have done it and got out but I wasn't feeling brave that day.

[mkhari]

Yep 7l stage now welded to hip and bailout to offboard OC practised.

Good on yer, not carrying stage bailout just means you want to die

[Digger]

I've run out of O2, on a dive trip whre O2 fills were an issue, and I'd only got one dil bottle at the time. I went in with about 30 bar, and spent half of the dive OC. It was a 15 bimble type dive, I wouldn't get in with that kind of pressure on a deep dive, but then if you know you've not got a lot of O2 and you are carrying a lot of bailout it ceases to be an issue.

Realising you've just emptied most of a bailout bottle that's 2 years out of test on the other hand...

Digs.

[MixedUp]

This is one of those deathtrap OC twinset rigs.

They should be banned.

[Mark Chase]

OK but just how little gas are you prepared to jump in with?

I did a couple of hours deco with none once

No diluent that is

Least I have dived with was 30bar of 02 and maybe 50bar of diluent.

On the Islands (9m deep) in Dahab All the other divers were single tank so I wasn't expecting a long dive.


My average CCR dive is 120 -180mins and ill use 50-70bar of 02 and 50-100bar of diluent depending on the profile.

On a livaboard diving trimix depths Ill do two dives of two - three hours each on a 3ltr blown to 240bar 02 240bar dill.

If we do a short dive i can often stretch it to three dives out of a three ltr

Depth isnt that relevant


ATB

Mark

[MixedUp]

Your PO2 is dropping as you're ascending but you've run out of O2. What's to stop you firing in some DIL and running SCR? .... as you'd been practising.

Well first of all if you fire in some dil then you are going to drop the PO2 even further.

Agreed if your loop volume was low due to not having O2, then it would at least allow you to breathe.

Finally, I think, I fail to see how you can ascend on SCR, going back to my last point, it would keep you alive (and that is the most important thing) but you would not know what mix you were breathing, (maybe there was a 4th cell) my classic would not tell me what I was breathing.

[Depth-junkie]

Good on yer, not carrying stage bailout just means you want to die

hahaaaaaaaaaaaaaaaaaaaaa, nope it means some folk are a bit more clued up and have better prep than others.

I dive alpine and have never ever run out of DIL or 02 EVER!!! regardles if it be a 100m+ dive or a shallow 10m bimble. I dont think my 02 bottle pressure has ever dropped below 70bar at the end of a dive regardless of depth.

On the other hand i have seen folk who carry shed loads of OC bailout run out of DIL and 02 on dives, seen loads off people exiting the water with no 02 left. But i have never seen a fellow aplinist run out of 02 or DIL....................i'll let you work out why that reason is