44 replies to this topic

[netmage]

I haven't thought through all the trade-offs but is it possible to wear a full face mask with a rebreather?

Yea - a number of folks are vocal advocates of FFM in response to OxTox convulsions - as I understand it they too have their own sets of complications...

So far the only reasonible thoughts I've seen focus around practices such as:
- 1.0 setpoint for bottom
- flying manual - e as backup
- cracked valve to allow fast response to stuck silinoid (sp?)

[Walter]

Walter,

I've been around enough RB's and RB guys now, to understand where the problem's seem to be coming from, but I just don't understand the MINDSET.

Actually, I think you'd like the rebreather if you gave it a chance. It seems to fit into your diving philosophy. It's very very zenlike and can put you at ease in the underwater environment. But like anything else, it's a tool. If you don't need the tool, don't buy it or use it.

Nothing wrong with OC.

I'd love it! I just am not convinced they are safe enough for me to trust.

I was under the impression Zak's death was ruled human error. Why do you say it was a bad unit?

I was under the impression Rob actually had a buddy, but made a solo ascent. I also heard he had jury rigged his mouthpiece.

Facts in all these seem to be in very short supply, mostly just rumors.

[ScubaDadMiami]

The overwhelming majority of incidents are caused by human factors. The training covers equipment issues because they can, do and eventually will happen.

Solo diving was not the cause of the accidents with CCR divers. The cause was the same as on the dives where there are other divers present. The only question is whether having a partner would have changed the outcome once the accident happened. However, one could raise this issue with either open or closed circuit.

For years, I solo dived because I found that the risk of diving with most people I encountered was much higher than diving alone. For the past few years, I finally found a number of people in whom I can trust, and I have been lucky enough to do most of my dives with people like this.

Since switching to CCR, I have solo dived a few times. Mostly, this was because I did not have a buddy that would be willing to go out to spend a dive sitting in one place while running drills in shallow water. So, it was a necessary evil.

I admit to enjoying being on my own in the water, and I feel even more liberated on CCR than I did with open circuit. The last thing you want to do on CCR is to be surrounded by a large crowd of noisy, bubble-making divers that are scaring away all of the fish life away. I am about ready to cut the hose of all the people with underwater quackers, and people whose computers are constantly beeping, disturbing my tranquility. I might even throw in a few more that kick up the sand everywhere they go, ruining the pristene conditions before I have had a chance to enjoy them.

I enjoy dives with other CCR divers, and I prefer to dive with other people even if they happen to be on open circuit. However, just having a buddy in name is just as high of a risk as diving solo, sometimes higher. So, if that is all I will get out of the relationship, I might just opt to go my own way at times.

[PerroneFord]

The overwhelming majority of incidents are caused by human factors. The training covers equipment issues because they can, do and eventually will happen.

I enjoy dives with other CCR divers, and I prefer to dive with other people even if they happen to be on open circuit. However, just having a buddy in name is just as high of a risk as diving solo, sometimes higher. So, if that is all I will get out of the relationship, I might just opt to go my own way at times.

This is the meat of the matter.

Nearly all deaths in SCUBA, both OC and CC seem to derive from human error. As you say, the REAL question at hand is whether an attentive buddy could change the outcome. When you consider that the only two things a buddy GENERALLY has to do to save his partner is offer gas, and get them to the surface, it seems that even an average buddy could make a huge difference. The problem with solo diving is we'll never have proof positive of it.

To your point of a bad buddy being worse than solo, I am inclined to agree. The danger is you THINK you have a buddy, and you really don't. So gearwise and mentally, you don't PREPARE to be solo. But then you are. At depth. My solution... thumb the dive immediately. Re-rig for solo if that's your thing. Or abort the day and dive again some other time. The water's not going anywhere.

[PerroneFord]

I'd love it! I just am not convinced they are safe enough for me to trust.

I was under the impression Zak's death was ruled human error. Why do you say it was a bad unit?

I was under the impression Rob actually had a buddy, but made a solo ascent. I also heard he had jury rigged his mouthpiece.

Facts in all these seem to be in very short supply, mostly just rumors.

Honestly Walter, I've done as many dives around RB's in the past 6 months as I have OC. I've played with them, torn them apart, and put them back together (well the Dive Rite anyway). In my opinion, the only dangerous part of MOST rebreathers is the person on the loop.

RB deaths are ruled human error, or medical condition to remove liability. Zak's RB had handset issues from what I am told.

Rob had a buddy on the surface. He was solo at depth. He jury rigged his mouthpiece and instead of his buddy watching him like a HAWK after he watched him do a quick field repair on the deck, he wandered off to do his own thing when the got to the bottom.

Facts are often in short supply if you are not in the know. RBW is a great source, but there are a limited number of people out there who investigate these types of deaths, and analyze them. I am fortunate to work with one of those people. We discuss most of these instances when they happen, but I am often not at liberty to say much.

What I can say, is that if your "buddy" is further away than you can comfortably swim to after an exhale, you don't have a buddy.

[Dive_Girl]

Rob had a buddy on the surface. He was solo at depth. He jury rigged his mouthpiece and instead of his buddy watching him like a HAWK after he watched him do a quick field repair on the deck, he wandered off to do his own thing when the got to the bottom.

Facts are often in short supply if you are not in the know. RBW is a great source, but there are a limited number of people out there who investigate these types of deaths, and analyze them. I am fortunate to work with one of those people. We discuss most of these instances when they happen, but I am often not at liberty to say much.

Facts must be in short supply because I thought the incident you describe above involved the diver reaching only 80' in depth, the issue(s) occurred, the diver switched to bailout, and then diver surfaced, totalling about a 4 minute dive time. That didn't read like some diver diving an bad rig wandering off from his buddy at depth. Maybe I am thinking of another incident.

[PerroneFord]

I've been taking an interest in RNs and I am curious, Perrone do you have any data, statistics or sources to back up your statements?

Most of the deaths I have heard of seem to be diver error - going too deep for the mix etc.

There is only one person that I am aware of keeping tallies of RB failures and he is only doing it for one brand of unit. The liability is HUGE for the manufacturers and so data is rarely publically available. So we are left to look at circumstances and draw conclusions with less than all the facts.

For instance, the cave diver who perished in Europe last month was diving a Meg. The Meg canister has a fairly well known issue with being used in cold water. The diver's profile (that was published) CLEARLY showed that the canister was exceeded.

In the death in South Africa on a body recovery, you literally watch on TV, the diver overbreathe his unit and die. The diver who went to recover him also died. I believe this was the situatiuon where you could hear his electronics handset crack from the pressure. I won't swear to it, but I belive that's the case.

If you are really interested in this, join Rebreather World and look at the section where they report accidents. You can go back quite some time and get pretty much all publically known details on this stuff, and read analysis by people who know and dive the units.

[Dive_Girl]

The diver overbreathe his unit and die. The diver who went to recover him also died. I believe this was the situatiuon where you could hear his electronics handset crack from the pressure. I won't swear to it, but I belive that's the case.

I don't believe this is correct. Don Shirley, Dave Shaw's friend waiting for him at 220m, had his Hammerhead controller implode while descending realizing there was an issue with his firend on the fateful dive but he had to turn back. He then got bent (a small bubble of helium had formed in his left inner ear) during his stops but he survived. They later recovered the body of the Dave Shaw (who was diving a Mk15.5 rebreather) and the body he was attempting to recover, Deon Dreyer, as they were both tangled in lines.

Click here for a detailed article regarding Dave Shaw's incident from Outside Magazine.

[PerroneFord]

Facts must be in short supply because I thought the incident you describe above involved the diver reaching only 80' in depth, the issue(s) occurred, the diver switched to bailout, and then diver surfaced, totalling about a 4 minute dive time. That didn't read like some diver diving an bad rig wandering off from his buddy at depth. Maybe I am thinking of another incident.

Please don't misunderstand me. Rob was a good diver. ONLY 80ft is a misnomer. If you had said only 10ft, I'd be inclined to agree. 80ft is darn deep when you cannot breathe. You are correct that he switched to bail out. Also managed to close the loop, and drop his harness weights if I remember correctly. All of that was done right.

We know that:

1. He flooded the loop which made him terribly negative (suspected)
2. He dropped weight to try to offset being negative.
3. He switched onto his bottle
4. He made it to the surface.

He was found just below the surface of the water, BC fully inflated. His bailout had plenty gas in it.

This led to speculation that he had some sort of medical malady. Apparently, he was not a young man, and might have had some previous medical issues. I don't know, and I am not going to armchair quarterback on Rob's death.

What bothered me about the incident was that his buddy was not available to him during this incident. In only 80ft of depth, with a diver who'd had problems with the breathing loop on his rebreather, why take the risk in the first 5 minutes? Or why take it at all. Just hang out with him for the dive. When I dive with RB guys, I am constantly watching their HUDs and watching them for any fooling with their loop.

I did a dive several monts ago with a fairly inexperienced KISS diver. I tried to remain close as it was clear he was trying to refamiliarize himself with the unit. He complained on the surface interval that I was too close. On the second dive, I gave him more room. At one junction, I was hovering about 20 yards away watching him try to get neutral. I was above and off to an angle. I saw him reach up and begin to fool with his loop. I got over to him as fast as I could, with my hand on my reg ready to do a share. I flashed an OK, and he flashed one back.

I spent 3 hours in the water that day with a max depth of less than 50ft, and I was never more than a few fin kicks away should I have been needed. It's not hard to be a good buddy. You just have to think about possible failure scenarios and how you could respond. You also need to be aware of what has happened (like Rob's field fix on his loop) and react accordingly. Certainly I am not laying blame at the feet of his buddy, Rob made the choice to dive on that rig. I just spent some time really thinking about the accident because I DO dive with RB guys often.

[Dive_Girl]

Please don't misunderstand me. Rob was a good diver. ONLY 80ft is a misnomer. If you had said only 10ft, I'd be inclined to agree. 80ft is darn deep when you cannot breathe.

My point wasn't so much the depth, any depth of water is an issue when your face is submerged in it and you can't breathe. I equate it sometimes to when is the most dangerous time to be on a plane - during take off and landing. Diving is not dissimilar. Don't skip buddy checks and be a good buddy, but since none of us were there - it truly is just speculation. Some incidents occur and his buddy could have been sharing his wetsuit with him and still been unable to stop the events from unfolding the way they did.

[PerroneFord]

I don't believe this is correct. Don Shirley, Dave Shaw's friend waiting for him at 220m, had his Hammerhead controller implode while descending realizing there was an issue with his firend on the fateful dive but he had to turn back. He then got bent (a small bubble of helium had formed in his left inner ear) during his stops but he survived. They later recovered the body of the Dave Shaw (who was diving a Mk15.5 rebreather) and the body he was attempting to recover, Deon Dreyer, as they were both tangled in lines.

Click here for a detailed article regarding Dave Shaw's incident from Outside Magazine.

Yep you're right. I watched this documentary on TV. I remember Shaw going in to recover the body and dying, and I remember someone going to get Shaw. I did remember the handset exploding. I thought that diver had also perished, but that was incorrect as you pointed out.

These guys were playing with fire, and they knew it. That situation is VERY different for me than some of the other stuff I've seen. Shaw, from what I am told, didn't have a lot of exerpeince with body recovery, if any. He was deep. I applaud Shirley for making the correct decision, and not diving to his own death making a triple fatality.

[ScubaDadMiami]

I am lucky in that I trained with one of the people that is also "in the loop" when it comes to getting the information on these accidents. One of the things that I was lucky enough to get from training with him was that he gave us a list of 35 scenarios that have resulted in CCR deaths or accidents, and we went over every one of the scenarios in class, with each student providing what he or she would do in such a situation.

I hope that every little bit of extra knowledge I can get will give me an edge should I ever need to use it in an emergency.

[Dive_Girl]

I am lucky in that I trained with one of the people that is also "in the loop" when it comes to getting the information on these accidents. One of the things that I was lucky enough to get from training with him was that he gave us a list of 35 scenarios that have resulted in CCR deaths or accidents, and we went over every one of the scenarios in class, with each student providing what he or she would do in such a situation.

I hope that every little bit of extra knowledge I can get will give me an edge should I ever need to use it in an emergency.

I would not doubt you are learning from some of the best and who are in-the-know. And I am glad to hear it!

[PerroneFord]

I am lucky in that I trained with one of the people that is also "in the loop" when it comes to getting the information on these accidents.

I was thinking of you when I wrote that. Your instructor and mine are friends. Should I take a RB course one day, I suspect I'll get much the same. I am sorely tempted to sit in on KISS class this week. Start's Friday. Grrr...

[ScubaDadMiami]

Sitting in never hurt anyone.