Team gas resource

[big_si]

Ok, so at my stage of diving at present (Adv Nit + Dec Proc) I'm happily planning dives and planning my gas useage to rule of 1/3's for back gas and rule of 1/2's for deco gas so should I or my buddy have an issue then then other person is carrying enough gas for the other person to come up safely too. Obviously this is a form of gas being a team resource.

As dives get deeper and deeper and gas requirements get more and more then obviously these volumes get higher.

I understand that the expedition style diving would be based on more than a buddy pair and this overage of gas is distributed more amongst the team so you don't all need to carry a squillion cylinders, there would / could be support divers / deco trapeze.

I was just wondering at what sort of stage does this sort of planning start to become more necessary / sensible? And what sort of form does this planning take?

Would a simple example be something like diving in a 3, deco gas you would plan to use 2/3 and the extra 1/3 (x2 buddies) would be for the diver with the issue? Obviously a good buddy system focused / skilled team would be necessary for this technique to be usable. When would or Would you use a gas plan of this kind?

What are people's thoughts?

[liamm]

is the difference between a 1/3 and a half really worth the effort? - you are saving carring 1/6 i think .... maybe i read the post wrong. Theres always going to be the issue of becoming separated from the group/shot/support divers so i'd be happier knowing that we had enough gas to get us out in all scenarios.

[big_si]

Originally Posted by liamm

is the difference between a 1/3 and a half really worth the effort? - you are saving carring 1/6 i think .... maybe i read the post wrong. Theres always going to be the issue of becoming separated from the group/shot/support divers so i'd be happier knowing that we had enough gas to get us out in all scenarios.

That's my view too for my current sort of diving. I'd much rather have the extra gas available to me and my buddies.



I'm postulating about say 100m diving carry multiple multiple stages and say carrying 4 instead of 6 (I'm making that up as I have no idea on gas planning to those depths and don't have a planning program with me at work.) I'm sure at some point it makes more sense to plan a dive in this way. Just wondered if anyone on here does diving where that would be a factor?

(I'm assuming a lot of people will be doing those sort of depths on CCR rather than OC so there might not be that many empirical answers but I'd be interested in what people think.)

[stevechesh]

For me personally, all my gas planning is done only on what i would need, and i try to come back with about half my gas. Rarely happens, but it's a plan!

Me and my mate both got caught out a few years ago when we got separated and my deco reg just wouldn't stop freeflowing. It was Ok before the dive but got filled with crap whilst digging down into a wreck.

We got split up in the bad vis so i was on my own for the ascent with stacks of deco and not enough gas. Made a decision to change one of my regs from my twins over onto the deco tin. That worked and i got out of the water ok. Now, for any deco dive i do, i always carry a spare tin of nitrox. That spare tin isn't included into any calculations. It's just "bonus" gas if i, or anyone else needs it.

When i first started deep diving, it was "everyone back to the shotline and trapeze". We had 3 bars on the trapeze, 9m, 6m, and 3m. On each bar was a spare cylinder of deco gas and a couple of regs on each and it was comforting to know that there was always plenty of gas. Now i just carry the lot.

My advice to you, would be do not rely on a buddy to have enough gas for you as well if it all goes pear shaped. Carry what you need and a bit spare, as they may not be with you at the end of a dive.

it's something you need to sit down and have a full and frank discussion with your buddy about. The rule we have is that if we are together at the end of a dive and he is low on deco gas, then he will go onto his backgas (assuming he doesn't have his spare tin with him) whilst i finish my deco. When i've finished, i'll go onto backgas and he'll use the remains of my tin and vice versa. if he does have his spare tin with him, then he'll go onto that one and so no real dramas. No point having two potential casualties if you can help it.

[Steve Jones]

Best plan on deeper dives is that everyone returns to the shot.

There is lots of gas available for you when you get up there.

Steve

[big_si]

Originally Posted by stevechesh

My advice to you, would be do not rely on a buddy to have enough gas for you as well if it all goes pear shaped. Carry what you need and a bit spare, as they may not be with you at the end of a dive.

Certainly sounds like a solid plan. My diving at the moment allows me to deco out on my backgas reserves (as I always produce a lost deco gas plan.) I wondered if that was something that changed with the much deeper dives where this isn't a realistic choice. Sounds like you have a good procedure to deal with it should the brown stuff hit the whirly thing.

Originally Posted by stevechesh

it's something you need to sit down and have a full and frank discussion with your buddy about. The rule we have is that if we are together at the end of a dive and he is low on deco gas, then he will go onto his backgas (assuming he doesn't have his spare tin with him) whilst i finish my deco. When i've finished, i'll go onto backgas and he'll use the remains of my tin and vice versa. if he does have his spare tin with him, then he'll go onto that one and so no real dramas. No point having two potential casualties if you can help it.

Yeah, that's the procedure I use too.

[Steve Jones]

Originally Posted by stevechesh

it's something you need to sit down and have a full and frank discussion with your buddy about. The rule we have is that if we are together at the end of a dive and he is low on deco gas, then he will go onto his backgas (assuming he doesn't have his spare tin with him) whilst i finish my deco. When i've finished, i'll go onto backgas and he'll use the remains of my tin and vice versa. if he does have his spare tin with him, then he'll go onto that one and so no real dramas. No point having two potential casualties if you can help it.

Well done Chesh, just make sure you and the other OC guys bring lots of gas on my April trip. I might even do some bail out drills, breathing on your gas of course, not mine.

Steve

[stevechesh]

Originally Posted by Steve Jones

Well done Chesh, just make sure you and the other OC guys bring lots of gas on my April trip. I might even do some bail out drills, breathing on your gas of course, not mine.

Steve

Thats absolutely fine mate.....Just be aware that my nitrox is made from 100% welding o2

I might even bring a J with me......

EDIT.....If i've got this right, there's only 2 of us on OC....So that means we'll need to carry 10 bailout tins between us for you deathbox divers to use! Oh no....hang on. We're bound to have some natural wastage on the boat with all those bleeping handsets that say NO DIVE!!!

[big_si]

Originally Posted by stevechesh

Thats absolutely fine mate.....Just be aware that my nitrox is made from 100% welding o2

I might even bring a J with me......

Side slung or mounted to the side of your twins?

[stevechesh]

Originally Posted by big_si

Side slung or mounted to the side of your twins?

Nah, i mount it on my helmet next to my torches!