Bigdiver(Offline)

How was everyone trained to deal with lost gas scenarios? Or at least what have you found most effective? Particularly GUE style.

I was trained (TDI) to follow this procedure...
1- Buddy breath deco bottle
2-Wait out buddies stop.... and take their bottle.
3- Deco on backgas

Thanks

iani(Offline)

Well I can think of one DIR diver on here who's method of dealing with lost O2 is to ask CCR divers if they can pop down and collect it...no names

Ian

Chris B(Offline)

My understanding is the deco would be doubled for that deco bottle, so if 50% 'lost' and carrying O2, deco on back gas for twice the planned time then revert to normal at the next bottle.

Example
You have 30mins to do on 50% and 30mins on O2
You loose the 50% bottle before you reach 21M
You start doing 1H of deco (doubling all stops) until you reach the O2 bottle then it is back to 30min's deco.

Another acceptable option (for me) would be to share your buddies deco bottle but not buddy breath EG so as they finish each stop, they give the reg to you to do that stop before you both move up and repeat until all the bottle is finished then you are both on double deco.

with three and using 1/3rds for deco gas, (plus rock bottom) then there is enough total gas between the team for one diver to do the whole dive with no cylinders!.......theoretically.

Rock Bottom reserves insure between you, there is always enough gas to get the other all the way out with no missed stops, all be it with up to double the time.

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Brian Allen(Offline)

There are lots of different methods for coping with this situation.

For tech 2 we were taught to extend the stop by 50%, and for each diver to use the deco bottle for half the time. eg 8minute stop becomes 12 and each diver does 6 minutes on the deco gas and 6 minutes on backgas.

I believe this is conservative and within gas planning since we plan for 1.5 x the required deco gas anyway.

Brian

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Bigdiver(Offline)

Am I correct in thinking that different methods are taught between the tech 1 and the tech 2 courses?

Naturally the method you choose is going to effect gas usage differently and thus effect over dive planning.

Alastair(Offline)

It's not so much that Tech-2 teaches different methods more that you have more options as you'll have more than one deco gas. You also potentially have a much larger deco requirement and a straight doubling would be impractical in terms of the amount of gas to be carried.

Cheers
Al

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MonkSeal (Online)

So there's more then one deco gas to loose.

Alastair(Offline)

Hey with a team of three you've got 6 deco cylinders. You've got to be having a really, really bad day to lose more than 3 of them

Cheers
Al

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