Learned Wrong...

[MXGratefulDiver]

Two comments and a question:
Do you know if it was intended as a decompression dive?

Better to find the belt on the bottom than on a corpse.

I find 35 Lbs is a lot of lead have on my hips, to handle, or jettison. I try to keep my belt at or below 10 KG/22 Lbs for all these reasons. Above that, something like the DUI Weight & Trim System is worth considering due to the shoulder straps, the 40 Lb capacity, and the ability to drop half at a time. I saw a diver pull one weight pack at a time and hand it up to the boat to lighten his load climbing the ladder. They are a little bit of a hassle to reload though.

I doubt it was intended as one (given the single-tank rig), but it's not unusual for divers in that area to exceed NDL's ... I've done so myself in that area many times ... sometimes by more than 20 minutes. It's all recreational depth (120 fsw and above), but it's easy to get down that deep and remain there for some time, assuming a big enough cylinder. Steel 120's and 130's are popular here.

I agree about splitting up the weight ... I limit my own weightbelt to 20 lbs, and wear the rest on my backplate for just that reason.

I also agree that it's better to find a belt than a body. But I think it's better still to not put yourself in a position to have to make that choice ... which isn't all that difficult to do. A diver has no business being below a depth they can swim themselves up from unless they have a redundant source. If you take that simple step, then a buoyant ascent should never become necessary ...

... Bob (Grateful Diver)

 

[*dave*]

Is using Google cheating?

Not in my book.

It's a review question from chapter 3 in the current SSI OW manual. It seems to me it is being presented as a viable ascent option.

 

[Akimbo]

…. A diver has no business being below a depth they can swim themselves up from unless they have a redundant source. If you take that simple step, then a buoyant ascent should never become necessary ...

There’s that word “should” again. I’m more inclined to put my chips on “when” while betting my life... or even ego. Can you imagine how much crap you guys will pile-on if I’m the next body recovery! :shocked2:

My preference is to have a redundant source deeper than I can do a free ascent, though I have violated it too many times.

I have become skeptical of added layers of backup over the years, probably an artifact from deep diving operations. It is disconcerting seeing so many “safety” and “backup systems” conspire to make accurate diagnosis and correction difficult and time consuming. This has proven deadly way too often. Sometimes the systems are fine but the physical burden nails you when the situation worsens. Take eCCRs for example. They are actually pretty simple, it is detecting and diagnosing potential failures accurately and quickly that is the challenge. Interesting times.

 

[Deep South Divers]

Wow! I go diving, and this thread has literally taken off...

For what it's worth, I have to admit that I have really enjoyed this discussion. It's a fantastic mental exercise, brain-munched by some of the best, most talented divers here on Scubaboard. I am thrilled that this has taken a run into science and "what if" scenarios and opinions of all types, from many backgrounds. Mostly, I'm pleasantly surprised that this hasn't turned into some kind of flame war.

[M values (what I was calling "N2 loading") are different for a scuba diver vs. an escaping submariner] is true for slower tissues, but not faster tissues.

True, if we want to be specific... But I was thinking in general terms, as an average of all compartments.

In any case, N

2 loading on recreational Scuba divers is low enough that the probability of any DCS symptoms are low, even at 120'/minute ascent rates.

It depends. A recreational diver could load themselves quite nicely with poor profiles, poor fitness levels, and multiple dives, say on a liveaboard. I mean, if you're going to give a generalization like, "If it's a last resort, use a CESA or use an EBA," then the diver that's right at their NDL must be considered.

Regardless, I still don't see a reason to favor an EBA over a CESA.

Your list is irrelevant. The body count is way too high to argue that divers don’t screw up or become victims of unanticipated circumstances.

I'm sorry, but I don't see a "high body count" in the statistics that I have seen. Do you have evidence to support one? If so, do you have some sort of evidence to support the idea that EITHER a CESA or EBA would have prevented a fatality? If so, do you have evidence that an EBA would have prevented MORE fatalities than a CESA?

I am genuinely interested in your point of view - especially because I know you enough to have a lot of respect for your background, both in terms of education and experience.

The bastardization is teaching a small portion of free ascents and thinking it is adequate. Nobody cares about the title. It is all the over-weighted divers found lifeless on the bottom shallow enough to freedive wearing their weights and empty cylinders.

Agreed. My example early on in this thread of the diver that was wearing 128 lbs of non-ditchable lead is a perfect scenario for showing why proper weighting is necessary. He drowned in 14 feet of water because he ran out of air without a buddy, and couldn’t get to the surface. That’s it.

If he had been properly weighted, a simple CESA could have been performed, and he’d have never even known he was in an emergency.

Alternatively, if he’d been able to ditch enough weight to enable a swim-up or EBA, then he’d still be alive also.

…So in this way, I can see why someone would need to ditch weight at depth in the case of an OOA without a buddy. But as I said in the beginning, he SHOULD have ditched the weight – before the dive, not during.

I mean, there’s the overweighted diver, and then there was this guy, who literally had two five-gallon buckets with him for all of his lead.

Dumping weight at depth would have saved his life. It also would have saved his life had he been ANYWHERE near “properly weighted,” which I discussed with him many months prior. His accident happened exactly as I told him it would, and I was pissed that I spent my time retrieving his lifeless body… And even more pissed that I had to be the one to tell his wife and family that he wasn’t coming home.

The answer to how to survive this scenario doesn’t lie in creating another cluster-f (EBA) to correct the cluster-f in the first place… Diving with 128 lbs of lead. The answer is to be properly weighted and preventing the problem of being an OOA diver with no buddy at depth in the first place. In error of that, a CESA would be natural and appropriate.

How about you are approaching your planned minimum cylinder pressure to leave bottom. For whatever reason you get separated from you buddy — visibility is bad, the surge is up, he’s a macro photographer focusing on a critter, or she found a better looking guy.

Heh.

It doesn’t really matter. Then:
(each bulleted item is an “or” not an “and” to the scenarios)

• You experience a total loss of air. Perhaps an HP O-ring or blow-out plug fails, an LP hose lets loose, or flow just stops because your rental cylinder has clogged your regulator inlet filer or valve dip tube. The important part is there is nothing left to breath by the time you figure it out. You can’t inflate your BC and you fear the additional drag of all that inoperable gear will reduce your chances of survival.

CESA. I don’t know a faster way to the surface.

• You swim into a wad of monofilament and can’t get lose. You remove your cylinder, still breathing from it, to get unhooked. Three is a hopeless knot of stainless wire entwined with the mono and you sense inhalation resistance on your high-performance balanced regulator. That means about three more labored breaths before you pass out.

…So I’m entangled, without a buddy, and totally out of gas? Well, if I can’t free the rig, then I guess I’m leaving it there… No choice. Total abandonment of gear is neither a standard CESA OR EBA… And since almost all of my weight is in my bp/wing, I’d likely be bouyant anyway. This scenario would end with me swimming like hell to the surface, probably bouyant… I guess both a CESA and an EBA.

• You start to vent your BC when the corrugated hose pulls off in your hands. You start to sink during your night dive and the option is drop your 3 Lb negative $8,000 dollar camera or your 20 Lb $50 weight belt. You try to swim against the current and negative buoyancy and notice the needle approaching 300 PSI as the debate continues. You are tired, concerned, and not sure what to do if anything else goes south. Your computer shows green in the deco box.

Well, I can’t see that happening, since I don’t pull on my corregated hose, and it’s double-bolted with two screwed clamps… But I get your point… Let’s say that the wing was catastrophically completely holed and totally inoperative, right at the end of my dive.
Depending on my depth, I’d be negative by less than ten pounds, I’d simply swim the rig up… Probably not even classifying as a CESA.

• The bottom is somewhere past 600' on a wall dive. You feel funny and uneasy. Suddenly you get a splitting headache and lose all vision. Your weight belt is 16 Lbs and your BC has 40 Lbs of lift. You can’t sense if you are losing or gaining depth. You have no idea how much longer you will be conscious.

Um… Turn to my buddy and signal “not okay, vertigo?” Maybe attempt to reorient myself against the wall? Thumb the dive and ascend in a controlled manner? Signal “OOA” and receive a donation, in case the issue is the gas in my tanks? I don’t see what a “blow and go” would achieve in this scenario, and there are a lot of safer options to deal with a depth problem at depth, rather than compound it with a bouyant, immediate and uncontrolled ascent.

It’s nice to have this debate with someone who is actually considering the replies.

Likewise, my friend. I am very much enjoying it, even if we disagree. Who said that we all have to agree?

I think it would be great to find a compromise that has no risk, is easy to teach, and actually works.

The truth is that the only difference I see between what you’re suggesting as an emergency bouyant ascent and my suggestion of a controlled emergency swimming ascent is the dropping of weight. In both cases, the diver is positively bouyant, whether he dumps weight or not. With an EBA, he’s a lot more bouyant, that’s all. In both cases, there is some semblance of control – less for an EBA than for a CESA.

…So it really boils down to REALLY bouyant vs. a little bouyant, and degree of control of the ascent.

To me, simply swimming up seems like the most simple and effective method, offering the most control and either a faster or slower ascent rate than what can be achieved in an EBA. I don’t know why anyone would not perform a CESA in place of an EBA.

 

[Thalassamania]

Here's the real questions:

Have you ever done a buoyant emergency ascent? Have you ever trained to do one? Do you know what one feels like? From what depth(s)?

Have you ever done a CESA? Have you ever trained to do one? Do you know what one feels like? From what depth(s)?

 

[gcarter]

Two comments and a question:
Do you know if it was intended as a decompression dive?

Better to find the belt on the bottom than on a corpse.

I find 35 Lbs is a lot of lead have on my hips, to handle, or jettison. I try to keep my belt at or below 10 KG/22 Lbs for all these reasons. Above that, something like the DUI Weight & Trim System is worth considering due to the shoulder straps, the 40 Lb capacity, and the ability to drop half at a time. I saw a diver pull one weight pack at a time and hand it up to the boat to lighten his load climbing the ladder. They are a little bit of a hassle to reload though.

As a newbie, and being of the "older" persuasion, and being a generally safety conscious type, uncontrolled ascents was definitely a training takeaway as one of the things to be avoided. I have had some inadvertent experience with rapid ascent as I learn my buoyancy, and I don't like it, but have learned to slow it some with position.

The BCD I use is a weight integrated back inflate -SeaQuest Balance. I am currently diving 28 lbs. 3 in each rear trim pocket, 6 in each ditchable front pocket, and 10 on a belt. My thinking is that I can ditch a bit, enough to change my buoyancy profile, without having to go whole hog and risk a completely uncontrolled ascent. And if dumping 6 isn't enough, I can dump another 6. Or another 10. I don't care about the cost of potentially losing weights, I care about control.

If I had any doubts about making it up, I would ditch a pouch in a heartbeat. But to me it isn't an all or nothing proposition. I doubt I could control ditching 28lbs right now. I think I would have a shot if I ditched 6.

I need to spend more time on basic skill development and practice, though, to get any real comfort with either CESA or EBA. IMO, not enough focus on this in the training. It is too much information packed into too short a time frame. Anyone coming out of their OW with an instructor who teaches to the standards (of course there are exceptional instructors who will go way past the standards, but they are not the rule), however wonderful that instructor may be, is not near as ready as many think they are.

I recognize quite clearly the limits of the training I received and where my skills need further work. I can state with confidence that my 16 year old son, as quickly as he caught on and as much a natural in the water as he is, does not really understand how much he still has to learn. From other divers I have seen and things I have read on here and elsewhere, he is not atypical.

 

[Darnold9999]

For the benefit of others reading this, a little perspective is in order: The use of SPGs weren’t wide-spread until the mid-1960s to the early-1970s. There were marginally effective reserve or J-valves, but were in the minority and all but the inexperienced and ill-trained actually depended on them. A fully-instrumented diver had a depth gauge, compass, and a watch.

And a significant percentage had just a depth guage. Watches were expensive. Personally I had just the depth guage. Steel 72, horsecoller BC with CO2 charge, single reg - no octo. (and a humungous dive knife stapped to my leg) Did not do multiple dive days back then - needed a watch, and it was just too cold anyway. I do remember creating the habit of checking the pull rod on the j-valve as often as I now check my SPG. (kelp was a significant problem pulling the rod as you moved through it). As we practiced ditching weights (doff and don) and CESA until we were comfortable was not overstressed by the idea that I might run out of gas at depth. Never happened but didn't worry too much about it.

 

[Deep South Divers]

I did so, the links don't tell me much. You make the statement on your web page: "Studied at Duke University's Hyperbaric Facility for the U.S. Navy." I don't know how to interpret that. What did you study? Who was the P.I.? What papers came out of it? Were you a co-author on any of them or were you an experimental subject?

(sigh). I was being facetious. My "diving resume" shouldn't really come into play. The only question that hasn't been addressed is, "Why would a diver choose an EBA vs. a CESA." or, "What advantage does an EBA have over a CESA?" I still haven't seen one.

For what it's worth, I was one of the many divers that were studied during the US Navy's most recent "Flying After Diving" studies. Unlike most subjects, however, I became very entrenched in the data and participated in several steps of the study, including assisting with gathering of the data. I was there for more than two months total, over a period of about three years, studying with those who ended up changing "flying after diving" time from a decades-long 24 hour recommendation to a 12 hour recommendation. I did not write any papers on the subject, as it was not my study.

I learned a tremendous amount from my participation, however, and had the chance to learn alongside today's most progressive hyperbaric technicians, medical personnel, and decompression scientists.

Going diving causes a pre-DCS condition, each and every time.

If what you mean by this is, "There are always bubbles in the bloodstream," then yes, you are correct. The exact point at which these become a medical condition is under a great deal of debate, and varies from person to person day to day for different reasons. Unfortunately, decompression science is lacking consistent exactness.

My point in my quote above is that clearly, creating an uncontrolled emergency bouyant ascent is going to potentially aggravate a "bubbling" condition.

If you look at DAN's figures (something that I try not to do because of problems that I feel are inherent to their data set) you will note that fatalities stemming from DCS are almost non-existent,

Well, I'm all *for* using any data source you suggest. Do you have another? I don't see that any one source could be more credible than Duke University's Hyperbaric Unit (probably the most world-recognized expert source regarding hyperbarics) and Divers Alert Network (the US Navy apparently felt this way, too), but if you think you have a more credible source, then let's see it.

...but there are a sizable number of drowning or just plain dead diver on the bottom cases.

Where?

This leads me to the conclusion that the recreational community has it's collective head up it's nether orifice when it comes to developing a rational approach to the teaching and conduct of emergency ascents.

Maybe. I'm open to it - the recreational community's training tends to disappoint me, too, as a general rule. I don't know of any reason why a diver would choose an EBA over a CESA, though, so if you've got a specific case that demonstrates why to choose an EBA over a CESA, then by all means, share.

I would not call that an "accepted scientific resource." That is an actuarial article written for the insurance industry by an M.D. It is not science.

Well, it IS written by an M.D. who apparently did quite a bit of research prior to publishing an article. If you have a better source, then by all means, share.

I have written extensively, even here on ScubaBoard, about the myriad problems of combining the data set that I help develop at the National Underwater Accident Data Center (that's the pre-1993 data) with the subsequent DAN data set. If you look at the two data sets separately you do reach some different conclusions ... but I feel that those conclusions are due to differences in data collection methods and analysis rather than reality.

You may be right... I would love to see what you're talking about.

I've seen hundreds of autopsy reports that give the cause of death as "heart attack" with are, if the truth be know, merely supposition with no definitive evidence.

Me too. The example that I used earlier - the guy with 128 lbs of non-ditchable lead on - was listed as COD - "Heart Attack" to "spare friends and family the embarrassment of what really happened" (coroner quote to me)... That he weighted himself so much that he couldn't get off the bottom, and drowned.

I disagree ... but, in any case, even a heart attack victim has a better chance of survival on the surface than he or she does on the bottom ... no?

Um... Sure, I suppose... Since a diver is positively bouyant after his first kick upwards, I don't see why it would make any sense to drop a weight belt, unless that diver is looking to forego control entirely. If the diver feels that his best chances are at the surface, then go there. That's called a CESA.

A few kicks will not get you to the surface, and surely will not help you to relax as you head for the surface, a flared buoyant ascent will.

Well, it depends on depth and what sort of streamlining and fins and that sort of stuff, as to how many kicks it's gonna take... But I wasn't saying that "a few kicks will get you to the surface," I was saying that a "few kicks will get you positively bouyant." A few more will get you another breath out of that dead tank. A few more will get you more positively bouyant, and a few more still will get you another breath. Repeat until you're at the surface. There is no need to drop weight and then "flair," trying to resist a "missle" style uncontrolled ascent.

I don't remember recommending inflation of the BC, except in the context of using an Air Siphon technique that is way more controlled than finning your way up.

No, not directed at you. Another poster had mentioned inflating the BC and/or life vest in another post.

A modicum of effective training is what turns the "very unusual" into the perfectly normal. Being underwater is, at least on the face of it, "very unusual." If you were to go through my class you would have made ten to twenty flared ascents (as part of the doff and don exercises) in each pool and session. Times ten to twenty pool sessions, that renders it hardly a "very unusual" body position.

You're REALLY attached to this EBA, aren't you?

Better to surface than to drown, no?

Of course.

If the diver is truly out of gas then there is no way to inflate the BC (even with CO2 cartridges, they were basically useless anywhere except on the surface or very shallow). Drop the belt, it works.

Swim up and do the same thing without dropping your weight belt. It works too, and allows you to control your ascent. It even allows you to be positively bouyant while doing it... No ditching of weight necessary.

You appear to me to be arguing from mistaken assumption rather than actual experience, and actually you've got it backwards. An 80' CESA is far more difficult than is an 80' EBA, you've just never been trained to conduct the latter nor performed the latter or you would realize that.

Wow. No, you're incorrect on my training... Or that I have assumed anything. Perhaps sometime we can get together and we can demonstrate to each other our ideas of 80' CESAS and 80' EBAs.

Do you have any data to support this or is this entirely based on assumptions that may or may not hold up? If you have data to support this I would love to see it because it flies in the face of my personal experience.
We have already dealt with this question, if you have data, or even just a line of reasoning, please present it; just saying that it is so is insufficient.

Okay, look... Let's discount everything I've said here. Let's say that I have zero proof that a controlled swimming ascent is more controlled and therefore safer than an uncontrollable (or not fully controlled) bouyant ascent.

Why would a diver choose an EBA over a CESA? Can you tell me any advantages - other than it's "easier" (which I disagree with)?

That speaks more to the folks that you have seen diving than it does to reality. In the old days almost every diver was ended OOA, with with a CESA, a gentle, controlled, slow ascent to the surface.

Exactly. Note that they did not then drop their weight belts and flair themselves and ascend to the surface in an "EBA" manner. They CESAed.

You're repeating yourself ... this has been answered.

It wasn't a question... It was a statement, and a direct answer to a question regarding M values.

 

[Deep South Divers]

Who are these people that can do CESA out of air from 80ft? If they can, great, do that.

I can do it from 130 feet.

What I experienced when I had a real-world OOA emergency with no buddy around (the one and only time I will ever have to do it in real life), was tilting my head back and swimming like hell while going, "Ahhhhhhhh!" all the way to the surface. Okay, let me correct that... What I said was actually "Oh****oh****oh****o****!" I think I said a lot more choice words, too.

Well, by 50' or 60' or so, I was out of lungs. I had, by that point, completely vented my lungs and was swimming like hell for the surface in utter and eerie silence. The world began to turn black, and I began to wonder who would find the body and what my family would say about me and how I had died.

Well, by that point the bubble in my wing had expanded considerably, and I was quite bouyant, no dropping of weight necessary. But what really freaked me out was how much of a dumbass I felt like when I instinctively breathed in and got... Another breath. Wait, maybe I'm not really OOA...

I finished the rest of my dive ascending at 30 fpm, and even stopped at 10' for a minute or two.

Now that I know that an OOA isn't really if you're ascending, I would safely tell you that within PADI's recreational dive limits (which includes both time and NDL), a CESA can be performed from all depths. In fact, you'll actually have time to vent your wing to prevent too-fast of an ascent.

Dropping weights? Why?? That would only exaserbate the problem.

 

[gcarter]

Um... Sure, I suppose... Since a diver is positively bouyant after his first kick upwards, I don't see why it would make any sense to drop a weight belt, unless that diver is looking to forego control entirely. If the diver feels that his best chances are at the surface, then go there. That's called a CESA.

You keep repeating the assertion that a quick kick or two and you will be positively buoyant. I think that part of the problem is that so many divers - especially new ones - are over weighted.

With 21 total dives, the last 17 in cold water with my current gear, I have been max weighted at 32lbs. I could not easily hold a 5m safety stop - kept wanting to go up. Over the course of the summer, I have dropped to 28 lbs, and on my last dive had to keep air in my BCD to maintain my SS, indicating I am ready to drop more weight. In the spring, I am going to start at 26. This is all related to my relaxation and breathing in the water, a shift of weight of 6lbs. A couple of kicks will now get me closer to buoyant than it did a year ago, but a year ago it would have been more work.

So for a not atypical over weighted recreational diver, is it not possible that just kicking up is not as simple as you are asserting? I guess my point is that as an advanced diver you may be oversimplifying, assuming a capability / skillset / gearset / experience level that may not actually exist for an average recreational diver of the weekend warrior sort.