Video from a Training Dive with John Chatterton

[wetb4igetinthewater]

His point - I think - is that you shouldn't PLAN a deep technical OC dive with sharing gas as part of the plan.

I hope no one disagrees with that point. But I'm really curious as to the exercises he references here: " These are also exercises to prove to divers that they never want to involve a buddy in a gas supply emergency other than passing off a bottle". That's important stuff. Reality can be quite unforgiving.

 

[doctormike]

I hope no one disagrees with that point.

I think that a lot of people disagree with that point. Google team bailout.

 

[doctormike]

Here's more on gas sharing from JC...

 

[CptTightPants21]

OK, maybe you didn't edit it with the intent of making him look bad, but judging from the response that you got, I think that was the effect. Again, people who are interested in this should read the whole article.

His point - I think - is that you shouldn't PLAN a deep technical OC dive with sharing gas as part of the plan. Despite his colorful imagery, I doubt that he would watch someone drown for lack of shared gas on a recreational dive. The point is that if the two of you are deep and saturated, and sharing gas means that one or both of you has a significant chance of surfacing bent or dead, he's not going to let that happen, and he's not going to plan a dive where that might happen either.

Now many may say that you shouldn't have to make that choice, that we do team diving and we plan for the team to carry enough gas to get everyone safely to the surface. That's fine, but it's a different philosophy. It's one that most divers these days follow, but it's not the only way of diving. It's not solo deep OC diving - again, read the actual article for a better description of this topic.

Finally, I know that this sentence is likely to cause a lot of concern: "Breathe your own damn gas, any gas, even the wrong gas"

He's not trivializing breathing the wrong gas. The point that he made in class was that ox tox is exposure and time. So if for some reason your bottom gas is completely unavailable, breathing a richer mix while you make a fairly rapid ascent to the MOD for that gas may be safer than a CESA from depth. Can you get away with that? There is a lot of individual variation in tox thresholds. EAN100 at 240 FSW? Maybe not. EAN50 at 140 FSW? Maybe so...

I read the whole piece and I think the article is blending too many topics. I don't think anyone was doing a dive plan where the team was sharing deco gas as part of the plan. There is self-reliance and being able to handle emergencies on your own (which is fine), there is the team aspect of I have a reserve if something goes wrong that either you or I may use and you have the same reserve. When we plan deco gas and back gas calculations we typically will either do a full min gas calculation or leave a third of the gas as reserve to cover all the "what-ifs". This is the we need 1.5x our required bailout or deco gas for XYZ dive plan.

I did not get the impression that John Chatterton was making a case against reserve gas planning and doing dives where he is planning on using all the gas he brings down with him, but he is confusing both divers having this reserve as "team" gas planning.

Someone who has taken the class--what gas calculation rules were taught and done during class?

 

[cerich]

Finally, I know that this sentence is likely to cause a lot of concern: "Breathe your own damn gas, any gas, even the wrong gas"

He's not trivializing breathing the wrong gas. The point that he made in class was that ox tox is exposure and time. So if for some reason your bottom gas is completely unavailable, breathing a richer mix while you make a fairly rapid ascent to the MOD for that gas may be safer than a CESA from depth. Can you get away with that? There is a lot of individual variation in tox thresholds. EAN100 at 240 FSW? Maybe not. EAN50 at 140 FSW? Maybe so...

I bolded something you said. Because it is important.

as far as a CESA from depth on a technical dive... drowning is a better way to go IMHO and I will choose that.

Now, if I have gas staged say on the line and I think I can get to it breathing the wrong gas I'm gonna give it a shot. It will be exceptionally unlikely to work but why not?(keep your workload low and try and control breathing rate and you'll be less likely to O2 tox) That said if a hypoxic mix it will just get worse as you ascend and the odds go from really bad to powerball bad.

Now, to underline something, Ox Tox is exposure and time but that time can be very short (as in a few breaths) depending on PPO2, personal tolerance at that time (which even in individuals will vary significantly day to day.. got a scar to prove it from toxing in a chamber while starting a hang over while still pretty much wasted)

 

[wetb4igetinthewater]

I think that a lot of people disagree with that point. Google team bailout.

Yeah, I think team bailout only works in ideal situations of clear viz, open water, and zero currents. When it comes to diving ancient wrecks in the Aegean, there can be some tricky currents that are not evident at the surface. My source? A retired sponge diver who had been diving for over 40 years and has probably been bent more times than I have technical dives.

Here's more on gas sharing from JC...

That's really not relevant to this discussion.

 

[CptTightPants21]

I think that a lot of people disagree with that point. Google team bailout.

I am sure some experienced CCR divers will come back with some stories, but at this point I have seen more concrete evidence about Big Foot than I have that an actual CCR team practices team bailout for their gas emergencies.

 

[cerich]

I think that a lot of people disagree with that point. Google team bailout.

that is another thread.

IMHO team bailout is more about pretending that you aren't diving akin to mountain climbing without a rope (which if you want to have at) without having to always try and put up with the "you need bail out!" crowd. The only thing that bugs me is that some instructors teach it and believe it... I can point out MANY more times it failed than it worked. YMMV

 

[cerich]

I am sure some experienced CCR divers will come back with some stories, but at this point I have seen more concrete evidence about Big Foot than I have that an actual CCR team practices team bailout for their gas emergencies.

is that a joke? every day CCR divers dive "planning" team bailout. Because a 40 is not gonna cut it at 60-70 m on the wall and in fact I know of one "huge team" CCR dive in Cayman where it literally took almost 10 CCR divers carried BO to get a diver to the roof alive. So, team bailout worked... ;-)

 

[rjack321]

That said if a hypoxic mix it will just get worse as you ascend and the odds go from really bad to powerball bad.

How so? Even the most hypoxic bottom gasses are breathable up to 20ft - which assumes you have no intermediate deco gasses at all. Seems odd to me to be on a 10/70 or 12/65 dive with only O2 for deco.

I use a long hose on virtually all of my diving (OC, CCR, SM, BM) because its easy, streamlined and I can. The entire concept (in JC's text) of fending off a panicky OOA diver is ludicrous. Do you know how strong panicked drowning diver/swimmers get? There's a reason that every rescue course and CG rescue swimmers always approach victims from behind. Drowning people WILL take you down with them.