Diving to 200' and Beyond

[Bennno]

Instantly drop dead? Who said that?

You just claimed that rebreather diving is not more dangerous than walking down the street... that ridiculous. Where is the report that says that?

 

[oya]

Instantly drop dead? Who said that?

You just claimed that rebreather diving is not more dangerous than walking down the street... that ridiculous. Where is the report that says that?

Not quite what I said. Rebreather diving is significantly more dangerous than walking down the street. You're wearing a piece of devious equipment on which you depend to survive in an alien environment that is deadly to us.

I said people die on rebreathers at about the same rate as people walking down the street.

The DAN Annual report shows 64 reported rebreather fatalities over 2010-2013. Unfortunately no one has the actual numbers on how many divers or dives were made in that time, so there's no way to establish a baseline, but it can safely be assumed that there were several tens of thousands of dives made over those four years. So 64 fatalities in several tens of thousands. It's not a bad record. And most of those fatalities can be traced back to user error... and that's a whole different discussion.

Now if you point out a group of, say, 10,000 people to me, I'll point out that at least 64 of them are going to die within four years of various causes including heart attack, infected testicles, speeding buses, old age, bears, electrocution, and (in one particularly interesting case) a box of accordians tumbling from a third story window.

 

[Bob DBF]

For someone to cavalierly come back from a 200 foot dive where they put the entire boat at risk of psychological trauma and physical danger, then refer so dismissively to people on vacation and doing appropriate levels of diving, my thoughts are pretty straightforward...

May be you need to apply the same thought to some tech divers I have personally met. They also dive to those depths on backgas and bailout, and may use trimix, like the lady in question, they also treat mere rec divers quite dismissively. Assuming they dive like they talk, I'd not buddy with any of them.

If you never want an accident in diving, and for everyone to speak correctly topside, then the industry needs to institute strict medical, psychological and training tests to stop the carnage and hurt feelings. I figure a 90 to 98 percent reduction in divers should make that goal possible. I'm not betting we would make the cut, but it would make diving safer, until the diving industry itself collapsed. With no divers there would be no dive related problems.



Bob

 

[PfcAJ]

Not quite what I said. Rebreather diving is significantly more dangerous than walking down the street. You're wearing a piece of devious equipment on which you depend to survive in an alien environment that is deadly to us.

I said people die on rebreathers at about the same rate as people walking down the street.

The DAN Annual report shows 64 reported rebreather fatalities over 2010-2013. Unfortunately no one has the actual numbers on how many divers or dives were made in that time, so there's no way to establish a baseline, but it can safely be assumed that there were several tens of thousands of dives made over those four years. So 64 fatalities in several tens of thousands. It's not a bad record. And most of those fatalities can be traced back to user error... and that's a whole different discussion.

Now if you point out a group of, say, 10,000 people to me, I'll point out that at least 64 of them are going to die within four years of various causes including heart attack, infected testicles, speeding buses, old age, bears, electrocution, and (in one particularly interesting case) a box of accordians tumbling from a third story window.

Your thinking on this topic is incredibly convoluted.

For starts, you did say that "they die at roughly the same overall rate as people walking down the street". Now its "significantly more dangerous than walking down the street".

Just look at figure 1.6-5. 8% of fatalities were on RBs, compared to 65% on OC. Think about it for a second: Do you think 8% of all dives conducted are on rebreathers? Its disproportionate.

Trying to downplay the risks of rebreathers is ridiculous.

 

[oya]

Trying to downplay the risks of rebreathers is ridiculous.

So we've established you don't like rebreathers.

I'm not attempting to downplay the risks. I wasn't really trying to introduce rebreathers into the discussion... it's just what I know. Yes, they're more dangerous than walking down the street (because you're underwater), yes, they're more dangerous than OC (because they're more complex and have more serious failure points). But they aren't de facto deadly.

Diving is dangerous, but can be done safely. Rebreather/cave/deco diving is even more dangerous, but can be done safely. Given practice, training, and discipline. The original point I was trying to make above was that risky activities can and should be mitigated as best they can on behalf of the participant as well as the people around them.

Someone who enjoys a week's vacation diving no deeper than 30 feet and straying no further than 100 feet from the boat... AWESOME! Enjoy your dive. Someone wants to do a 5,000 foot cave penetration at 300 feet... AWESOME! Enjoy your dive. Stay safe and stay within the scope of your training.

And, returning to the point I tried to make above: Don't create unintentional victims by doing dives for which you are neither trained nor equipped for; if you do, you're an ass.

NOTHING in this entire industry drives me crazier than when I hear people (lamentably often) come back from Belize where the DM took them to 150 feet. And they wink at you conspiratorially when they say, "I don't think we were supposed to go that deep, but we were only there for a minute." That behavior by dive professionals and strengthened by encounters like the little French woman at the beginning of all this is what causes normalization of deviance. And leads to a strong showing of the entire 100% of dive fatalities.

When someone dies diving, they aren't the only victim.

 

[PfcAJ]

So we've established you don't like rebreathers.

I'm not attempting to downplay the risks. I wasn't really trying to introduce rebreathers into the discussion... it's just what I know. Yes, they're more dangerous than walking down the street (because you're underwater), yes, they're more dangerous than OC (because they're more complex and have more serious failure points). But they aren't de facto deadly.

Diving is dangerous, but can be done safely. Rebreather/cave/deco diving is even more dangerous, but can be done safely. Given practice, training, and discipline. The original point I was trying to make above was that risky activities can and should be mitigated as best they can on behalf of the participant as well as the people around them.

Someone who enjoys a week's vacation diving no deeper than 30 feet and straying no further than 100 feet from the boat... AWESOME! Enjoy your dive. Someone wants to do a 5,000 foot cave penetration at 300 feet... AWESOME! Enjoy your dive. Stay safe and stay within the scope of your training.

And, returning to the point I tried to make above: Don't create unintentional victims by doing dives for which you are neither trained nor equipped for; if you do, you're an ass.

NOTHING in this entire industry drives me crazier than when I hear people (lamentably often) come back from Belize where the DM took them to 150 feet. And they wink at you conspiratorially when they say, "I don't think we were supposed to go that deep, but we were only there for a minute." That behavior by dive professionals and strengthened by encounters like the little French woman at the beginning of all this is what causes normalization of deviance. And leads to a strong showing of the entire 100% of dive fatalities.

When someone dies diving, they aren't the only victim.

I own (and dive) a rebreather. I like it a lot. But the added complexity (and potential for error as a result) is what makes them dangerous.

The last 2 paragraphs of your post I agree with.

 

[Bennno]

Stay safe and stay within the scope of your training.

Don't create unintentional victims by doing dives for which you are neither trained nor equipped for; if you do, you're an ass.

Again, she IS diving within her training. You, Pete and some other people just see this story from the American POV. You might not like that rule but stop claiming she is breaking the rules.

How would you know that diving to 200' on air is more dangerous than diving your CCR... you don't. Tons and tons and tons of people are still doing dives like that... maybe not in Florida or in Mexico or in the other 'American vacation' places. I'm not saying everybody should head out and do deep air dives, but saying deep air to 200' is stupid but CCRs is super save makes no sense and is totally hypocritical.

And going back to your point of 'most accidents are user errors', duh. So are accidents on OC. People will make mistakes and OC is much more forgiving than any type of rebreather. Maybe that lady had tons of stuff happening to her in 40 years (which is likely). You guys are judging the lady on hearsay.

And one more thing. Is it just me or are tons of people have started claiming CCRs are totally save in recent years... there seems to be a shift in perception. Pete even claimed that CCR in a cave might be safer than OC... which is quite a remarkable comment I think.

 

[oya]

Again, she IS diving within her training. You, Pete and some other people just see this story from the American POV.

I had a mentor who would run the old Extended Range/Deep Air class. I'm not talking 200 feet, I've been to 200 feet on air many times... I'm talking well past.
He tried to talk me into becoming an instructor, I wouldn't. I refused to so much as participate or assist in one of those classes or dive with anyone who was going to be doing those sorts of dives.
He got horribly bent eventually. That class has long since been discontinued.
"Training" doesn't always equal "good idea." There is such a thing as poor training. There is such a thing as a philosophical shift in training.

I'm not looking at it as an American. I'm looking at it as a dive professional.

And one more thing. Is it just me or are tons of people have started claiming CCRs are totally save in recent years... there seems to be a shift in perception. Pete even claimed that CCR in a cave might be safer than OC... which is quite a remarkable comment I think.

Again: CCRs are complex and potentially dangerous provided you don't get trained, practice, and treat them with respect.
But: If I'm in a cave and I swim back to a point where I find some inconsiderate jerkoff has removed my navigational lines or markers, whats more, they kicked the hell out of visibility when they did it, and I now have to try find my way, blind, out of a maze... I'd far rather have the hours and hours allotted by a CCR than be trying to control my breathing as I watch the needle.

 

[Bennno]

For years 'deep air' courses have 'only' gone to 55m, no?
Deeper than that I don't think is a good idea.
In a cave or in conditions that are less than optimal I wouldn't go deeper than 130' either.

But: If I'm in a cave and I swim back to a point where I find some inconsiderate jerkoff has removed my navigational lines or markers, whats more, they kicked the hell out of visibility when they did it, and I now have to try find my way, blind, out of a maze... I'd far rather have the hours and hours allotted by a CCR than be trying to control my breathing as I watch the needle.

That I agree with, but it's the one upside on 'normal' little cave dives... the breather is still more likely to really punish a mistake way harder than OC does.

 

[Storker]

You, Pete and some other people just see this story from the American POV.

I wouldn't be so sure about that if I were you.

CMAS International Diver Training Standards and Procedures Manual
Chapter 2
Standard 2.A.5: CMAS One Star Diver Training Programme 1
[...]
4. Competencies of a certified CMAS One Star Diver
[...]
4.2 A CMAS One Star Diver is qualified to dive within the following parameters:
4.2.1 To use air as a breathing gas;
4.2.2 To make dives which do not require mandatory in-water decompression stops;

tl;dr CMAS 1* = max 20m, no deco
One Star Diver Training Programme

CMAS International Diver Training Standards and Procedures Manual
Standard 2.A.6/ BOD no 183 ( 08-03-2013 )
CMAS Two Stars Diver

4. Competencies of a certified CMAS Two Star Diver
4.3 A CMAS Two Star Diver is qualified to dive within the following parameters unless he has
received additional training or is accompanied by a Dive Leader on any open water dive:
4.1.1 To dive to a maximum recommended depth of forty (40) metres with other SCUBA
divers of the same level;
4.1.2 To only use air as a breathing gas, unless he is certified to use other breathing gas
mixtures;
4.1.3 To make dives which do not require mandatory in-water decompression stops;

tl;dr CMAS 2* = max 40m, no deco. Further national restrictions may apply, e.g. our national flavor of CMAS 2* certifies you to max 30m.
Two Star Diver Training Programme

CMAS International Diver Training Standards and Procedures Manual
Standard Number: 2.D.7 / BOD no 183 (08-03-2013)
CMAS Three Stars Diver
1. Aim of the training programme
1.1 This training programme aims at introducing the fundamentals of dive leadership to experienced
certified CMAS Two Star Divers, which will enable them to plan, organise and conduct their dives
and lead other sport divers in open water, to a maximum recommended depth of PpO2=1,4b +
deep national regulation, meters in a safe and competent manner.

tl; dr CMAS 3* = max pPO2 of 1.4 bar (which is 56.7m or 186') and staged deco. Further national restrictions may apply, e.g. our national flavor of CMAS 3* certifies you to max 40m. However, the 3* cert is basically CMAS' version of PADI's divemaster, so it focuses more on dive leadership rather than on diving (deep).
Three Star Diver Training Programme