Gas planning for diving in mixed company?
- Thread starter stuartv
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The man himself, first post.
lermontov
Contributor
He will have been trained to get deco gas from his buddy in the event of a failure. But that assumes an OC buddy with equivalent deco gas. That may not be the case if the two divers are only allowed a single cylinder each for deco or bailout. So the choice of bailout becomes key.
As it stands he could be doing backgas deco split between two quite useless gases. Best way he will be decoing out on 30% and adding 15 minutes.
It is unreasonable of the skipper to expect a CCR diver to do a half proper deco dive with a single bailout.
OP
TDI Helitrox course standards require training with one deco gas. The instructor may train to use more, if the instructor wishes. My instructor chooses to stick to only 1 deco gas for the first tech diving course.
So, TDI doesn't say I can't use more - except indirectly by saying to only use what I have been trained for.
At this point, my thinking on this whole subject has been simplified. I will plan so that I only need 1 AL40 of deco gas. Then, I will either carry 2 of those with the same gas, or I will carry 1 and my buddy will carry an AL80 with the same deco gas that I'm using. I've already confirmed that he's okay with that.
And... I really need to get on with getting my TDI Trimix cert....
PfcAJ
Contributor
If everyone carries enough gas for 1 major failure, you'll have enough resources to easily manage 2 major failures on the dive.
OC guy can lose both his bottom tanks (that's two failures) and share CCR guys deep bailout to get to the next gas.
Ccr guy can lose his ccr and his deep bailout and share with OC guy.
OC guy can lose a deco gas and share ccr guys deco gas OR deco on bottom gas.
Ccr guy can lose the ccr and deco gas and share oc guys deco gas or deco on his bottom bailout.
1.5x the deco gas would be the minimum in this situation. 2x bottom gas needed to get to the gas switch when OC guy thumbs it (rock bottom or min gas, whatever you wanna call it).
OC guy can lose both his bottom tanks (that's two failures) and share CCR guys deep bailout to get to the next gas.
Ccr guy can lose his ccr and his deep bailout and share with OC guy.
OC guy can lose a deco gas and share ccr guys deco gas OR deco on bottom gas.
Ccr guy can lose the ccr and deco gas and share oc guys deco gas or deco on his bottom bailout.
1.5x the deco gas would be the minimum in this situation. 2x bottom gas needed to get to the gas switch when OC guy thumbs it (rock bottom or min gas, whatever you wanna call it).
OP
Yeah.... but, apparently, CCR guy is not inclined to any plan that involves him having to share my bottom gas or share my deco gas. He insists on being completely self-sufficient. Whether that's a standard CCR training thing or whether it's just him, either way, it's fine with me. He has the training and experience that he is fine with carrying all the bigger sized cylinders required.
I am the weak link. But, he's willing to carry all the gas he might need PLUS extra gas to cover my redundancy needs. As I am planning it now, I guess we'll simply have way more gas than we need, and with neither one of us exceeding our training limitations. I'm okay with that!
PfcAJ
Contributor
Yeah.... but, apparently, CCR guy is not inclined to any plan that involves him having to share my bottom gas or share my deco gas. He insists on being completely self-sufficient. Whether that's a standard CCR training thing or whether it's just him, either way, it's fine with me. He has the training and experience that he is fine with carrying all the bigger sized cylinders required.
I am the weak link. But, he's willing to carry all the gas he might need PLUS extra gas to cover my redundancy needs. As I am planning it now, I guess we'll simply have way more gas than we need, and with neither one of us exceeding our training limitations. I'm okay with that!
Sounds like you need to carry the gas based on the above guideline.
Last edited:
lermontov
Contributor
OP
We did 2 dives. One Saturday and one Sunday. They went well enough. The viz was not good on Saturday. It was better on Sunday. We left Pensacola Sunday afternoon and drove straight up to Morehead City, NC, for the Wreck Shark Shootout. So, we started diving again on Tuesday and will continue through Sunday. I'll post a more detailed report after I get home.
I've done 6 dives here, so far. Gotten a few decent photos in spite of not being able to figure out why my camera wasn't doing what I expected. I finally got clued in this afternoon and I am hoping for much better photos the rest of the week.
I've done 6 dives here, so far. Gotten a few decent photos in spite of not being able to figure out why my camera wasn't doing what I expected. I finally got clued in this afternoon and I am hoping for much better photos the rest of the week.
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