Mixed team (cc & oc)

[Gareth J]

I have spent most of the last 10 years on CCR, diving with OC buddies.
As a general rule, most of the diving has been to a maximum depth of 40m. So its general sport diving not technical.

Point 1 - Even though they have been briefed, and dived with me regularly, they really don't understand!
Different units have different BOV's. They need to practice with yours.
Even CCR buddies get confused by units they haven't trained with.

Point 2 - I carry enough bailout gas for both myself and the OC buddy. Granted only one of us can use it, if we both have failures its been a very bad day at the office.
I almost always dive with at least a 7l stage. This is the bailout gas for both my buddy and me. I can hand it off if my buddy needs it. (This is even though most of my buddies are on twinsets).

Point 3 - They need to tell you their decompression obligation, theirs is normally much longer than mine.
(I tend to run a OC computer so I have a fair idea of their deco' obligation is).

Point 4 - They need to warn me about gas issues - they generally are going to run out of gas way before me.

I had a period on OC diving with CCR buddies. Despite briefings, i had no idea how much I didn't understand until I actually did my CCR course!

Generally I treat my CCR diving with OC buddies as if I was diving solo on CCR. I carry my bailout, I watch my PO2's. If it goes wrong I need to sort the unit myself, if I can't do that I need to bailout. If it really goes tits up, they will at least get me back onto the surface, thats as much as I can hope for.

Gareth

 

[Zi55ou]

Reading all the replies I get the impression that the variations in configs makes what I asked for originally almost impossible unit/bov/dsv. As to my confidence level were I to have to get my buddy out of the water from a ca 30-50m dive with some deco, I'm not sure.
Prob have a look on the handset to see what his ppo2 is doing switch him to oc on the shrimp (off board) and head up.
Guess it's a discussion I need to have in more depth with him and the particulars of his setup, bov is easy it's connecting to his bo (usually one 80 unless we're practicing with multiple stages etc) so no switch from hypoxyic.
As an aside is rescue tackled in rb training or is the focus solely on avoidance rather than dealing with a poop sandwich?

 

[rjack321]

Reading all the replies I get the impression that the variations in configs makes what I asked for originally almost impossible unit/bov/dsv. As to my confidence level were I to have to get my buddy out of the water from a ca 30-50m dive with some deco, I'm not sure.
Prob have a look on the handset to see what his ppo2 is doing switch him to oc on the shrimp (off board) and head up.
Guess it's a discussion I need to have in more depth with him and the particulars of his setup, bov is easy it's connecting to his bo (usually one 80 unless we're practicing with multiple stages etc) so no switch from hypoxyic.
As an aside is rescue tackled in rb training or is the focus solely on avoidance rather than dealing with a poop sandwich?

Having done unconscious buddy ascents from 30m (many times) actually completing more than a few minutes of deco is probably not happening. If my problem is medical (heart attack, stroke etc) staying in the water is actually making matters worse.

 

[KevinNM]

In general I'm in agreement that if you encounter an unconscious CCR diver, the odds of a successful rescue are low. The bulk of CCR training is about not getting to that point in the first place, so if a diver gets to that point, he or she has already either had a serious medical event (that will probably kill them in a cave or soft overhead situation anyway), or they've made a series of mistakes in pre-dive checks and/or system monitoring that are entirely their fault, so don't beat yourself up over it.

It does happen. I was told of a diver who somehow managed to go diving without a scrubber installed and got pulled out unconscious by other divers who noticed her pass out. She was fine, though I'm not sure how the come to Jesus discussion with her instructor afterwards went.

 

[rddvet]

Having done unconscious buddy ascents from 30m (many times.

I don't ever wanna dive with you it seems

 

[Zi55ou]

I don't ever wanna dive with you it seems

Just go to 31m, you'll be fine!

 

[rjack321]

I don't ever wanna dive with you it seems

Something about DMing in tech classes causes me to pass out!

 

[wedivebc]

Typically a problem for the CCR diver who tends to not carry enough bailout.

They do if they're diving with an OC buddy

Seriously if you know how to access bailout gas and the basic construction of the rebreather there is not much more to know. Remember rule of thirds don't apply in the same way since RB diver will not be consuming gas before bailing out so gas volume matching is important.

 

[DA Aquamaster]

They do if they're diving with an OC buddy

Seriously if you know how to access bailout gas and the basic construction of the rebreather there is not much more to know. Remember rule of thirds don't apply in the same way since RB diver will not be consuming gas before bailing out so gas volume matching is important.

I agree. I make it a point to remind an infrequent or first time OC team mate that I'm on a rebreather and have 6 hours or so of scrubber duration and O2 available, so I will not be turning the dive on "thirds" - that's on the OC team mate.

However, I also let him or her know that I will turn the dive based on penetration and bailout gas I have available, without relying on his or her gas for my bailout. I can usually give them a good idea where exactly that will be based on what I'm carrying for bailout. I try to "match" things within reason, since it's pointless for me to carry three stages and drop two of them for bailout when all he or she has for penetration is 1/3 of a set of double 95s (86 cu ft). Short of a significant CO2 hit, my LP 85 primary dil/out and an AL 72 stage (187 cu ft total) covers the exit gas for both of us in that situation.

 

[rjack321]

I usually have about 30-50% more reserve as BO than my OC buddies. If they were on thirds of double 95s (~85cf useable) I'd be cool diving overfilled 50s (~120cf)