Connect with us





Simon Mitchell, Session Moderator

Editors’ Note: The Final Consensus Statements are given below. The discussion that led to the consensus appears after the Consensus Statements. The discussion was excerpted from a transcript of the meeting provided by a court reporter. Editorial changes were made to correct grammar and remove extraneous comments. Every effort was made to retain the spirit and intent of the original discussion. 

Rebreather Forum 3 consensus. In: Vann RD, Denoble PJ, Pollock NW, eds. Rebreather Forum 3 Proceedings. AAUS/DAN/PADI: Durham, NC; 2014; 287-302. 



The forum acknowledged the overwhelming evidence demonstrating the efficacy of checklists in preventing errors in parallel fields that share similar technical complexity. Two recommendations regarding checklists were consequently agreed:

Checklists 1. The forum recommends that rebreather manufacturers produce carefully designed checklists, which may be written and/or electronic, for use in the pre-dive preparation (unit assembly and immediate pre-dive) and post-dive management of their rebreathers. 

  • Written checklists should be provided in a weatherproof or waterproof form.
  • The current version of these checklists annotated with the most recent revision date should be published on the manufacturer’s website

Checklists 2. The forum recommends that training agencies and their instructors embrace the crucial leadership role in fostering a safety culture in which the use of checklists by rebreather divers becomes second nature.

Training and Operations

Training and Operations 1. The forum applauds and endorses the release of pooled data describing numbers of rebreather certifications by training agencies, and encourages other agencies to join American Nitrox Divers International (ANDI), International Association of Nitrox and Technical Divers (IANTD), and Technical Diving International (TDI) in this initiative

Training and Operations 2. The forum endorses the concept of making minimum rebreather training standards available in the public arena.

Training and Operations 3. The forum endorses the concept of a currency requirement for rebreather instructors. We recommend that training agencies give consideration to currency standards in respect of diving activity, class numbers, and unit specificity for their instructors. 

Training and Operations 4. The forum recognizes and endorses the industry and training agency initiative to characterize ‘recreational’ and ‘technical’ streams of sport rebreather diver training. These groups will have different operational, training and equipment needs.

Accident Investigation

Accident Investigation 1. The forum recommends that training agencies provide rebreather divers with a simple list of instructions that will mitigate common errors in evidence preservation after a serious incident or rebreather fatality. 

  • These instructions will be developed under the auspices of the Undersea and Hyperbaric Medical Society (UHMS) Diving Committee in consultation with the relevant RF3 presenters.

Accident Investigation 2. The forum endorses the concept of a widely notified centralized ‘on-call’ consultation service to help investigators in avoiding errors or omissions in the early stages of a rebreather accident investigation, and to facilitate referral to expert investigative services. 

Accident Investigation 3. The forum recommends that in investigating a rebreather fatality the principal accident investigator invite the manufacturer of the incident rebreather (or other relevant equipment) to assist with its evaluation (including the crucial task of data download) as early as is practicable. 

Accident Investigation 4. The forum endorses Divers Alert Network (DAN) worldwide initiative to provide a means of online incident reporting with subsequent analysis and publication of incident root causes.

  • Halcyon Sidemount
  • Area 9
  • Subscribe for free
Design and Testing

Design and Testing 1. The forum recommends that all rebreathers incorporate data logging systems which record functional parameters relevant to the particular unit and dive data, and which allow download of these data. Diagnostic reconstruction of dives with as many relevant parameters as possible is the goal of this initiative. An ideal goal would be to incorporate redundancy in data logging systems, and as much as practical, to standardize the data to be collected.

Design and Testing 2. The forum endorses the need for third party pre-market testing to establish that rebreathers are fit for purpose. Results of a uniform suite of practically important unmanned testing parameters such as canister duration, and work of breathing (qualified by clear statements of experimental parameters) should be reported publicly. Ideally, this testing should be to an internationally recognized standard.

Design and Testing 3. The forum acknowledges recent survey data indicating a poor understanding of rebreather operational limits in relation to depth and carbon dioxide scrubber duration among trained users, and therefore recommends:

  • training organizations emphasize these parameters in training courses.
  • manufacturers display these parameters in places of prominence in device documentation and on websites.

Design and Testing 4. The forum strongly endorses industry initiatives to improve oxygen measurement technologies, and advocates consideration of potentially beneficial emerging strategies such as dynamic validation of cell readings and alternatives to galvanic fuel cells. 

Design and Testing 5. The forum identifies as a research question the issue of whether a mouthpiece retaining strap would provide protection of the airway in an unconscious rebreather diver. 

Design and Testing 6. The forum identifies as a research question the efficacy of a full face masks for use with sport rebreathers.


SIMON MITCHELL: This is a session in which we are going to try to pull together a lot of the things that have happened over the last three days. Neal Pollock mentioned that several of us have been keeping an eye on what has been going on to put together a series of statements that we can debate this afternoon. We are identifying some pragmatically useful points on which it might be possible to reach a consensus. A lot of this information will appear in the papers that individual authors will provide, but this is where we take ownership of it as a forum. You might think that some of these things are a statement of the obvious but remember that many of the people who read these proceedings were not here. You must also remember that we have not captured all the key points raised in the meeting. Much of what was discussed cannot be distilled into simple statements. If we have time at the end we can open the floor for any new points. 

I have pre-drafted a series of statements, which we will open for discussion. It is much easier to get discussion going and reach consensus if you start with something to argue about. If you raise a point that suggests that one of these statements needs to be modified, it will be changed in real time as we proceed. I ask you to avoid anecdotes that prove the exception to a particular point if that point is overwhelmingly supported otherwise. This is a very imprecise science. There is always a story that proves the exception to a rule. Those stories are not particularly useful if it is clear that we are going in the right direction. 

We will reach a consensus by simple show of hands and visible majority. If it is close enough for a count to be required, we will say there is no consensus. This is a very pragmatic approach.

This is our first draft statement: “The forum recommends that rebreather manufacturers produce carefully designed checklists which may be written and/or electronic for use in the pre-dive preparation and post-dive management of their rebreathers. Written checklists should be provided in a weather or waterproof form.”

There are a few elements of that statement which speak to some of the points that were made in the recent session. I think it was Gavin Anthony that pointed out that they have to be weather- and/or waterproof. I think it was Mark that pointed out that we are getting sophisticated in the way these devices can run these checklists for us. We already know there are rebreathers with electronic checklists. Some of them are forced checklists. So this embraces all of those. And it does not give any extra weight to either one at this stage, which is probably appropriate. We do not have evidence pointing to efficacy of one over the other. We are going to come back to encouraging checklists and creating a culture for them in the next statement. Is there anybody who would like to speak to this statement? 

JILL HEINERTH: Could I ask you to add that these be published on the Internet and marked with a date revision so that we are clear as to when they are current? 

SIMON MITCHELL: We will wordsmith and add that later. Anything else? 

KEN SWAIN: I would amend pre-dive preparation into two parts. Rather than pre-dive preparation, unit assembly and immediate pre-dive. Break it down into two parts. One putting the unit together and the other just before you roll in the water. 


JOSH THORNTON: As far as publishing them on the net, while sitting in this meeting I got on Go Daddy and purchased all versions of rebreather or CCR checklists domestic. Whether we put it together or turn it over to someone else, we encourage the manufacturers to put information up on our website. 

SIMON MITCHELL: Thank you. Is there anybody who disagrees with this statement? For the record, that statement is unanimously passed. 

The second statement speaks to the issue of creating a safety and checklist culture: “The forum acknowledges the overwhelming evidence demonstrating the efficacy of checklists in preventing errors in medicine. We, therefore, recommend that training agencies and their instructors embrace the crucial leadership role in fostering a positive safety culture in which the use of checklists by rebreather divers is emphasized.” 

I have not gone into details about how training agencies should do this. We could spend a lot of time talking about that. I also think that we should trust the training agencies to be sensible and understand the key role that they have. I am not sure that we need to be more specific. Let us open it up for discussion. 

TOM MOUNT: We have a checklist called a pre-safety drill check that is not unit-specific. It covers the things that must be done in the water within 15 min. 

SIMON MITCHELL: Thank you. Are there any comments around this particular issue about training agencies taking a leadership role in promoting a checklist culture? 

DALE BLETSO: I would only state that instead of saying “emphasize,” it “becomes second nature.” It actually becomes a cultural thing. They do not think about it. It is just done. Emphasize means you are kind of encouraging people to do it. It has to be part of the whole culture where it becomes second nature. 

SIMON MITCHELL: I do not have a problem with strengthening it. “Becomes second nature.” I think that is what we are trying to imply by culture. 

TONY HOWARD: I think we need to promote consistency and coordination across the industry so training agencies are not promoting unnecessarily different formats and all meet a minimum standard of what should be in the checklist. 

SIMON MITCHELL: I do not have a problem with the concept, but each rebreather is different in subtle ways. If I was a rebreather manufacturer, what I would say to you is, leave it to me to create the checklist for my rebreather and I will do a good job of that. I do not want to have to try to match what I am doing exactly with what the manufacturer down the road is doing. 

TONY HOWARD: I completely agree. That is where it has to be coordinated with the manufacturers. Many agencies will train on the same rebreather. We should have a consistent approach on the way each rebreather is trained for. The individual user may not know that the other agencies are dealing with it differently or the same. As an industry we should be consistent. The consistent approach should be apparent in future audits. 

SIMON MITCHELL: How would you alter the wording to that? 

TONY HOWARD: That is a damn good question. 

NEAL POLLOCK: Simon, the first sentence makes me uncomfortable. The focus of this meeting was not medicine. I believe you should take out the reference to medicine. 

SIMON MITCHELL: I am happy to take it out. The reason I put it there is because we had a representative of the educational profession telling us that in order to drive change you need an evidence base. We do not have that in diving. How many people in the audience would object to me taking the reference to the medicine out? 

GARETH LOCK: Just to change it to say “preventing errors in medicine.”

SIMON MITCHELL: What about “preventing errors in parallel fields?”

NEAL POLLOCK: The latter works. 

SIMON MITCHELL: Everyone happy with that? Is there anyone who wants to speak to this statement? 

UNIDENTIFIED SPEAKER: I think it should be the manufacturers’ checklist to make it clear that you are not dealing with lots of different checklists. I think “second nature” should be replaced with “mandatory.” 

SIMON MITCHELL: “Mandatory” is a strong word. How many people here would be happy with mandatory? I am one. How many people would be unhappy with mandatory? 

UNIDENTIFIED SPEAKER: How do we make it mandatory? 

SIMON MITCHELL: That is not the issue. It is a culture. We cannot make anything mandatory. 

RICHARD WALKER: “Mandatory” does have a legal implication you may not wish to introduce. 

SIMON MITCHELL: How many people are happy to leave it as it is? How many people insist that we change it? We will leave it as it is. What was the other suggestion? They are going to be manufacturers’ checklists, are not they? 

GAVIN ANTHONY: One of the recommendations is the manufacturers produce checklists. A lot of training agencies have their own way of presenting training information. If you define this as a manufacturer’s checklist, it may not fit in with the training way of presenting. 

SIMON MITCHELL: I take that point and tend to agree with it. 

LEON SCAMMERHORN: I think there is room for both philosophies. Generally, aircraft manufacturers produce procedures manuals and checklists for the aircraft. The operators in an air carrier environment then produce operational checklists based on the manufacturers’ form so that there is not a conflict. They can go further. Training agencies are primarily interested in the procedures, not the building of the unit. I would say that for a general statement perhaps the use of manufacturers’ checklists in coordination with the training agencies’ procedures. But the manufacturers cannot release the concept of specifying the limitations of the unit and the correct assembly and pretests of the unit. 

SIMON MITCHELL: Why do we not take this out?

JEFF BOZANIC: We do not want to make any text so specific, tying it to a manufacturer, training agency or anything else, such that we stifle information. 

SIMON MITCHELL: I think the intent of the statement is pretty clear and unambiguous. Time for a vote. Is there anybody who objects to this statement as it is currently written? For the record, we have a unanimously accepted statement. 

The third statement was generated during the last discussion: “The forum endorses the concept of making minimum rebreather training standards available in the public arena.” This does not disavow the concerns about legal implications. It is just saying what we would like to see. 

NEAL POLLOCK: Can it just be “recommendations” rather than the wordier “endorses the concept of….” 

SIMON MITCHELL: It is wordy. I think if I put “recommendations” in here, I am going to have a bunch of unhappy people. If I leave it as it is, is there anybody who would object to it? If I change it to recommendation, is there anybody who would object to it? There are a few. So I am going to leave it wordy. Is there anybody who objects to this statement? Good. That goes on the record as a unanimously accepted statement. 

Number 4: “The forum unanimously endorses the concept of a currency requirement for rebreather instructors.” I used ‘unanimously’ since Jill Heinerth already took that vote. Then it was Jeff Bozanic who said there are concerns. So, the forum recommends, not mandates, that training agencies give consideration to currency standards in respect to diving activity, student numbers and unit specificity for their instructors. In other words, we are giving guidance to the way we think they should think, the things they should think about, but we are not saying they have to do anything. Jeff, you were the one who raised that concern. Do you want to say anything? 

JEFF BOZANIC: Other than the fact that this is a very self-selected group that is probably much more active than the average recreational dive instructor, we must not lose sight of the fact that we have to keep the entire industry in mind and the applicability of what is going on. 

SIMON MITCHELL: And we are leaving it entirely open for the training agencies to do that in a sensible way. 

TOM MOUNT: The only thing is student numbers and class numbers. 

SIMON MITCHELL: Is there anybody who disagrees with this statement as it is currently written? Good. That goes down as unanimous agreement. 

Now, a little bit of background for the next three statements. We are going back to the discussion of accident investigation. A lot of this comes from David Concannon’s presentation. I think we all agree that inadequate accident investigation and the consequent lack of accurate data was a recurring theme. And to me and the chairs I have discussed this with, training small groups of accident investigators from the diving community, while not a bad thing in itself, does not seem like a plausible solution to the wider problem. Given the wide spectrum of potential equipment and the need to have the right person at the right place at the right time — a more generic solution seems necessary. I have identified two key points and generated a statement for each. One concerns the immediate aftermath of the accident. As David Concannon pointed out, people at the site will often do the wrong things with equipment. They will move switches, touch mouthpieces, and not take notice of the right things. And then comes the subsequent investigation. 

Here is the statement that will interest the training agencies: “The forum recommends that training agencies provide students with a simple list of instructions that will mitigate errors in evidence preservation commonly made early after a serious incident or rebreather fatality.” Now, we do not have a list, although the sorts of things that would be on that list have been presented at this meeting. Clearly, I do not want to get into a debate about the exact items on that list. This is a concept. But I would take responsibility under the auspices of the UHMS diving committee to compile the list in conjunction with the people that presented here at this meeting. What I am saying here is that in a rebreather mod 1 course there would be a slide in the course about what happens, what you do if there is an accident and what you do not do in the immediate aftermath. I expect this to be a little more controversial, but I am interested in your views. 

TOM MOUNT: I think it is a good idea, but you have to consider different countries and laws. Generally, when an accident has occurred, the legal standpoint is to preserve the crime scene. It is necessary to abide by this. I have no idea how you would develop it. 

SIMON MITCHELL: My sense is this list is not a complex list. It is more like, “Please do not touch the valves; please do not turn off the mouthpiece; please do not flick switches; please look at and record what the gauges say; but do not interfere.” 

RICHARD WALKER: I wonder if maybe this would be better put on the manufacturers than the training agencies with the protocol to contact the manufacturer for specific instructions. 

SIMON MITCHELL: We are coming to that next. This is when you first get out of the water, Richard. You know what happens, people interfere with stuff before they contact anybody. The manufacturers are not going to be there. 

RICHARD WALKER: Does it need to be anything other than “Do not touch anything” then? My concern is that it inherently makes the other rebreather diver subject to all the discovery and legal and testimony. Now they are caring for evidence and should establish a chain of custody. 

SIMON MITCHELL: I think you are getting a sense that this is going to be a protocol for a rebreather accident investigation. It is not. It is going to be a few key points of advice that you can fit onto a single slide that say, do not do this, do not do this, these are the obvious errors you can make. And the next slide is going to be getting on to contacting someone who can help you with the right advice straight away. 

RICHARD WALKER: I was concerned when you said writing down pressures and things like that. 

SIMON MITCHELL: We would take Mr. Concannon’s advice. 

GAVIN ANTHONY: I agree fully with the first paragraph statement. I have got some concerns with the second part; who will develop this. I think you need to make sure you have input from manufacturers and from the people who will be receiving this kit for study. 

SIMON MITCHELL: I would be happy to take that away. The only problem is we have not actually put it down as an action item for anyone. What I am asking is for this group to trust us to talk to the right people. 

GAVIN ANTHONY: To help you, I have one that has been agreed upon within the UK regulatory bodies that I can give you a template. 

SIMON MITCHELL: That would be great. 

STEVEN SELLERS: I would recommend that we replace the word “rebreather” with “diving” to address the situation where we may be dealing with mixed teams or whatever. 

SIMON MITCHELL: Except that then the list would be different. I understand what you are saying. With the other thing there too, we would, therefore, be recommending to all training agencies do this same thing. I am not sure that all would want to have a slide like that in their underwater diving course. 

STEVEN SELLERS: I think you have covered that with the terminology provided them with a simple list. 

SIMON MITCHELL: I agree with you, but this is a rebreather forum. I would prefer to leave it as it is. Let me do a show of hands. Who would like me to open this up to the entire diving industry? 

UNIDENTIFIED SPEAKER: It is already there. 

SIMON MITCHELL: I did not see it in the Professional Association of Diving Instructors (PADI) open water course or rescue diving course. Who thinks that we should take this from the rebreather realm to the mainstream diving realm? Put up your hands. We will leave it as it is. 

DAVID CONCANNON: I agree with Tom Mount. I think this is a good idea. I like the emphasis on simple lists and the simpler the better. I do not think it can hurt anything and it could be helpful. 

SIMON MITCHELL: Thank you for that. So we have a legal opinion. 

MICHAEL PIZZIO: We have to ensure that divers do not interfere with the evidence. 

SIMON MITCHELL: I totally agree. I think the message we got from David on the first day was that divers are interfering with the evidence. 

GRANT GRAVES: My only issue is with the students. Are we talking about entry level, because if we are going to start teaching people from scratch on closed-circuit, we do not give this information on open-circuit to rescue divers. 

SIMON MITCHELL: “Entry-level rebreather students?”

GRANT GRAVES: Yes, I am questioning “entry-level.” 

UNIDENTIFIED SPEAKER: What about just “rebreather divers?”

SIMON MITCHELL: Hang on. These are students having their first interaction with a rebreather training agency. So they are entry-level students, are they not? 

UNIDENTIFIED SPEAKER: I think you should remove “entry-level.” 

SIMON MITCHELL: I think that is reasonable. We will remove “entry-level” and leave “rebreather students.”

GAVIN ANTHONY: Can you take it one step further with “rebreather students and existing divers?” We are a big club, 30,000 people. There are a lot of people who are already trained that need this information. 

SIMON MITCHELL: I am going to include a footnote to recommend distribution to existing divers, where possible. 

SIMON MITCHELL: Okay. Is there anybody who now disagrees with this statement? That statement is carried unanimously for the record. 

The next statement reads, “The forum endorses the concept of a widely notified, centralized, on-call consultation service to help investigators in avoiding errors or omissions in the early stages of a rebreather accident investigation, and to facilitate referral to expert investigative services.” This could be achieved via DAN or equivalents in different countries in the world, in conjunction with or as a dedicated website. The point here is that everyone in this room knows if they go diving tomorrow and get decompression sickness, they will ring DAN. That is what we do. If we know that when you have a rebreather accident and you want to get an investigation going, it needs to be dealt with properly, that you also ring DAN, and the DAN person knows which website to refer you to or which person to contact. Then you have solved the problem of needing to have experts present in every single rebreather accident situation. You need a centralized referral service. I think this is a pragmatic solution to the problem, but I would be very interested in hearing from someone from DAN here who may want to comment on it. Is it reasonable to have a sheet of paper at the DAN phone saying, if someone calls and says they have a rebreather accident on their hands, this is what you tell them to do? What do you think, Neal? 

NEAL POLLOCK: Easy in principle. With the incident database we maintain, this is very logical. 

GAVIN ANTHONY: As someone who does investigations, I have often been presented with rebreathers where people have been given expert advice already and it has made my job an absolute nightmare. So I agree with the principle, but I am worried that when it gets to the expert investigation services that they receive equipment which has been tampered with. 

SIMON MITCHELL: That is exactly the point. So someone has an accident in the UK. I do not know what phone you have there, if you have a DAN phone. They say, “Do not touch it.” You can look it up on the site, but I am going to put you in touch with Gavin Anthony at QinetiQ and he is going to tell you what to do with this rebreather. The policeman on the site rings the DAN phone, and says, I have got a rebreather accident. The person on the end of the DAN phone says, you need to talk to Gavin Anthony; that is the whole point. 

GAVIN ANTHONY: I think “provided it” comes over in that manner. 

SIMON MITCHELL: That is the whole intent of what I am saying here. 

PETAR DENOBLE: Just to confirm that for the referral operation, I would not qualify experts but compile the list of experts. 

SIMON MITCHELL: Referral to expert investigative services implies that this centralized on-call service will have the right names to provide. And this is trying to get around the “I got a guy” thing. 

NICHOLAS BIRD: I am actually going to go a little bit against my colleagues on this one as the guy who oversees the medical services call center for a few very simple reasons. For me to provide medical information, I can do that. If I provide you more information, I start practicing medicine over the phone for somebody who I do not have a doctor-patient relationship with, and that puts us in a significant position. That is not good. I am just giving a context. If I all of a sudden start providing some medical legal advice, you have got an accident, and you are asking me about an injured person, for which I can say, you know what, it sounds like you should go to the emergency room, versus “I have got a guy,” which I realize – do you want me to create that list of approved people? Do you want DAN to be responsible for creating and maintaining that list for that industry? That puts a burden on DAN that we really should not get into. 

SIMON MITCHELL: I hear what you are saying, Nick. That is why I have got the word concept underlined there. This is an idea for getting around a problem that seems to me to be otherwise unsolvable. Now, whether that central referral source ends up being DAN or just a website, I do not really care. But the concept of a centralized resource is what I am getting at here. It does not have to be DAN. It could be achieved by DAN or equivalents and/or a dedicated website. We are not committing DAN to anything. 

NICHOLAS BIRD: The other part of this is I am also speaking about conversations I have had with our board who get nervous about DAN being in any kind of way a legal referral service. 

RICHARD HARRIS: As one of the doctors who answers the DAN emergency helpline in the Asia Pacific region, if DAN, the overseer of this telephone service, agrees that this is something that would work and it is safe for them legally, I think it would be an excellent resource. Because people know that DAN is the organization to call. And it is an excellent central resource that works very well, in my opinion. And as one of the people who picks up the phone, I would be happy to give that very simple advice, these are the people you need to talk to, and nothing more specific. 

NICHOLAS BIRD: Oftentimes we do not hear about fatalities or accidents for some time. 

SIMON MITCHELL: The concept is that you would hear about it because people would know to call you if it was something that DAN decided to take on, but DAN may not. DAN may just decide to host a page on their website or someone else may decide to host a page. What I am asking for here is an endorsement of a concept of a centralized resource. 

NICHOLAS BIRD: I do not disagree with the concept. I am trying to get down to an operational pragmatism, which is that it is very difficult for us – people know that DAN takes accident fatality information and has for the last 20 years. We still do not get called on most of those. We have got to find those things out. So it is usually not very efficient operationally. So I do not want to say we are going to do this and it does not work. We have not solved your problem. 

SIMON MITCHELL: The only way we are going to solve this problem is with a centralized resource. I am putting out the concept here. We are not going to resolve it today. We are not going to identify how that resource is going to be established. We are not going to establish who it is. But I think the idea of a central authority is the way to go. 

DREW RICHARDSON: Simon, you can preserve your conceptual idea if you eliminate the last sentence and address the controversy within DAN. There were some good points made here. 

SIMON MITCHELL: I do not think we should debate this for much longer, because we are not going to establish who it is and how they are going to do it today. It is the concept of being able to contact a centralized resource when you have a rebreather accident for expert advice. 

JAMES LAW: I find this idea very good. Having DAN as our first point of contact would be a double benefit since that way they would get the initial notification of a rebreather fatality. I think that would be a great idea to pursue. 

SIMON MITCHELL: If we agree on this statement, then I can tell you what I am going to be doing. I am going to be chatting with Nick Bird and Dan Orr offline and saying, can we make this work for you in any way? Let us talk to David Concannon. If this is not going to work, we will find another way of doing it. I think a centralized resource is our best chance of making sure the right people get involved in the right place. 

STEVEN NEUMAN: As a crime scene investigator, this might well be distributed through the Sheriffs’ association, law enforcement agencies, so that they are made directly aware. Having a lot of outside influences sometimes confuses the investigation. If you can educate law enforcement agencies, it might work better than having DAN hold the responsibility. 

SIMON MITCHELL: That is a good point. I think the concept, though, is that once we established it, the people we would want to educate would be divers. So that when they are involved in an accident, just the same way they ring DAN when they are sick, they contact this resource to get advice on management of a rebreather accident. 

PAWEL SZOPINSKI: I am just wondering if there is a point of involving manufacturers in such instances where each, for example, manufacturer could offer a point of contact. For example, when there was an accident on a rebreather itself, you could have that information or contact them. 

SIMON MITCHELL: We will come back to that in the next statement. Is there anybody who disagrees with this statement as it currently exists? There is one person in disagreement. So, carried by a clear majority. 

The next point that came out very strongly in several of the manufacturers’ presentations, “The forum recommends that in investigating a rebreather fatality, the principal accident investigator invite the manufacturer of the incident rebreather to assist with its evaluation, including the crucial task of data download, as early as is practicable.” This would stand whether the principal investigator is a policeman in New Zealand, a sheriff or Coast Guardsman in the United States, or a coroner in the UK. Would anyone like to speak to that? 

GARETH LOCK: Any of the manufacturers involved in the accident where you have got mixed open and closed-circuit divers, other download data may be useful in understanding what happened to these. 

SIMON MITCHELL: If I said “manufacturer of the incident rebreather or any other relevant equipment,” would that work? 

GARETH LOCK: That addresses an issue that Bruce had about data download. 

SIMON MITCHELL: From computers. Thank you. I personally agree with that modification. Does anyone object to that modification? Can we take a vote on this statement? Is there anybody who disagrees with this statement? Carried unanimously. 

Now we are changing track from rebreather accident investigation. I want to go on the record that you could have knocked me over with a feather when that paper handed to me with all those training numbers in it. That was an extraordinary thing, the likes of which we have never had before. My congratulations to you, gentlemen. “The forum applauds and endorses the release of pooled data, not individual agency data that identifies the individual agencies, but pooled data describing numbers of rebreather certifications by training agencies, and encourages other agencies to join ANDI, IANTD and TDI in this initiative.” Does anyone wanted to speak to this, particularly anyone from any of the other training agencies? 

SIMON MITCHELL: Drew, do you have anything to say about this? 

DREW RICHARDSON: Works for us. 

SIMON MITCHELL: I was just as blown away by the training accident data that you released at the fatality workshop, and PADI has been very open with their data. All right. Can we have a vote on this? Is there anybody who objects to this statement in its current form? Carried unanimously. 

JEFF FRANK: One of the exciting things I saw in this accident investigation presentation was the black boxes included in these machines. I saw several slides where the information was amazing, and a couple where the information trailed off after some period of time. I am wondering if we feel that the standards for data selection and retention are appropriate or if we need standards and/or certifications to put the computers and equipment to make sure that we retain the data after a computer sits on the bottom of the ocean for some time. 

SIMON MITCHELL: So your statement is something along the lines that we would be specifying some parameters that we would rebreather black boxes to meet in order to be useful to us? 

JEFF FRANK: Yes. Specifically, I am wondering if we can solve some of the problem of accident investigation with technology. We know it could be turned back on. We know it could be rattled in a Zodiac on the way back to shore. Can we make sure the computer operates in a way to save the data? 

SIMON MITCHELL: Some of the issues you raise are very specific. What we will do is hold these questions to see where we are at the end of presentation. If we address them now we will not get through the rest of the list. 

JEFF FRANK: All right. Thank you. 

SIMON MITCHELL: This is a really important initiative that was raised several times. It is obvious, but by endorsing this statement we are getting it into the public domain in the findings of this workshop: “The forum endorses the DAN worldwide initiative to provide a means of online incident reporting with subsequent analysis and publication of incident root causes.” Does anyone want to speak to it? Very good. Carried unanimously. 

Now we move into the area of design and testing. The statement reads, “The forum recommends that all electronic rebreathers incorporate data logging systems which record dive and functional parameters relevant to the particular unit, and which allow download of these data. Diagnostic reconstruction of dives with as many relevant parameters as possible should be the goal of this initiative.” As a footnote I want to state that an ideal goal would be the establishment of a common format and content for the data that should be collected. This gets to the point that the last speaker was making. If we and/or the manufacturers go down this path there will need to be some definitions, but it is not our job to establish them today. 

GAVIN ANTHONY: Can we take the word “electronic” out? 

SIMON MITCHELL: I thought about that and I put it in because of what the makers of the Halcyon RB80 are going to say when this comes out. In order to comply, they would have to install an electronic device in their electronics-free rebreather. Do you still think I should take it out? 

GAVIN ANTHONY: I would still like to see it taken out. Because most rebreathers at least have the O2 monitor. If you have that then you have got some capability of a black box. 

SIMON MITCHELL: I do not have a strong view. Let us take a vote on the issue of electronic or not electronic. Who would like to see “electronic” taken out of this so it says “all rebreathers?” And who would like to see it stay there as it is? It stays on a majority basis. 

PAUL HAYNES: Should it be “all future electronic rebreather designs?” Should it be “all future rebreather designs?” So you incorporate the up and coming generations. 

SIMON MITCHELL: I do not think that is the spirit of it, Paul. I think that what it probably should say is all recreational rebreathers. We would not expect oxygen units being run by militaries. Does anyone have an objection to me inserting “recreational” in there? 


GARETH LOCK: What about people getting a hold of commercial military rebreathers and using them? What I mean is keep it to “all rebreathers.”

SIMON MITCHELL: Does this spill over then with confusion about all rebreathers used by sport divers?

GAVIN ANTHONY: Before you change that, I am going to object. 

SIMON MITCHELL: Before I change anything, let us run with more discussion. 

NIGEL JONES: I think you should consider adding the word “redundant” to data logging systems. So the point being is if you have a single data logging system and it fails, what do you do? So if you are going to go to the trouble of doing it, should you make it redundant so that you have always got the data available?

SIMON MITCHELL: Nigel, to your knowledge, how many of the current rebreathers have redundant data logging systems? 

NIGEL JONES: I know of one. 

SIMON MITCHELL: Can I put that question to Martin Parker. 

MARTIN PARKER: We have the capability of doing it. We have never needed it. But we have three processors on the system so we have the capability. We do record a little bit of information in the controllers, but generally we record all the data in the handset. So we do not have a full redundant system in terms of all the information. 

SIMON MITCHELL: We will come back to your concern, Nigel. 

TOM MOUNT: Would it be more appropriate to say some means of recording it like an external computer? 

SIMON MITCHELL: Actually, I have a high level goal with this statement. What we are trying to do here is enable diagnostic reconstruction. I think Bruce Partridge has to be credited with that term. I think that should be our goal. 

GAVIN ANTHONY: I am going to go back to saying “all rebreathers.” This is not a sports diving rebreather forum. It is a rebreather forum. There are military, commercial. There is a range of people here. 

SIMON MITCHELL: I am going to take that out and say “all rebreathers.” I will address the redundant side of it in a moment. 

MARTIN PARKER: I think if you put it in, that is fine. But I have got a feeling that for us to change the format now would be very difficult. For Poseidon to change the format would be quite difficult too. I think it is probably going too far. 

SIMON MITCHELL: Would you object to it saying “common content?”

MARTIN PARKER: That is good. 

SIMON MITCHELL: I am happy with that. My sense, Nigel, on the issue of redundancy, is that I am reluctant to put it in there at this time. I understand that it would be a laudable goal, but let me ask Martin a question. You have had the opportunity to download data on a moderate number of accidents, because you have got a lot of rebreathers out there. In what proportion of cases have you failed to get that data? 

MARTIN PARKER: We have always managed to get the data from the deceased’s rebreather. No problem. It was just the one where the data was corrupted on the partner’s rebreather. 

SIMON MITCHELL: I would like it to be noted for the record that the issue of redundancy was raised and that I do not think any of us here would argue that in an ideal world we would have redundancy. But I do not feel inclined to put it in this statement. 

UNIDENTIFIED SPEAKER: Put it in a footnote. 

SIMON MITCHELL: I think that would be a reasonable thing to do. 

Is there anybody in here who objects to this footnote statement as it currently reads, “An ideal goal would be to incorporate redundancy and to establish a common content for data to be collected.” Objections? The statement is carried unanimously.

The next design and testing statement. “The forum endorses the need for third-party pre-market testing to establish that rebreathers are fit for purpose.” Ideally, this testing should be to an agreed universal standard and should result in public reporting of a uniform suite of practically important parameters such as canister duration. I would like to open that statement for discussion. 

KEVIN GURR: Could you add the word “unmanned” in there. 

MARK POWELL: Should the “result in” be taken outside of the “ideally” clause? 

SIMON MITCHELL: Kevin, Martin or Leon, what do you currently do? Do you publicly report the results of your pre-market testing? 

LEON SCAMMERHORN: It is part of your market plan: achieved scrubber duration under this workload, at this depth, at this water temperature. And you state what standard it was tested to. For example, we use the 14143 and US Navy criteria. We quote both. 

SIMON MITCHELL: So, in other words, if we took that out of the “ideally,” it would not be any imposition on rebreather manufacturers? I like that idea. So what we will do is we will put the – 

UNIDENTIFIED SPEAKER: Take out the word “ideally.” 

SIMON MITCHELL: No. I will wordsmith this a bit. Trust me that I will not change the meaning. It is just a bit hard to word it nicely. So we have taken the public reporting of the results out of the ideal realm and we have put the uniform standard in the ideal realm. 

UNIDENTIFIED SPEAKER: I would add “work of breathing.” 

OSKAR FRANBERG: I was referring to the “unmanned” statement by Kevin Gurr. Practical performance is a pretty big part of the European standards today. If we are going to have “unmanned” there, I think we should have “manned” or just take the “unmanned” away. I mean, just testing a rebreather unmanned is just not doing the whole thing. 

SIMON MITCHELL: Answer me this, Oskar, or someone who is familiar with the standards, is the pre-market third-party testing ever manned? 

OSKAR FRANBERG: There is a large part of the standard today which is practical performance. 

SIMON MITCHELL: So why did Kevin want it to be unmanned? 

KEVIN GURR: You are partially right. I should probably expand on this a little bit. The way it works under 14143 at the moment is the bulk of the work is done under a unmanned environment and then once the manufacturer is satisfied that you have a fit-for-purpose machine, there is then a section of 14143 that requires some manned analysis. It is not in a military environment. It is divers going out and doing test dives. 

SIMON MITCHELL: So why do you want it – 

KEVIN GURR: What I was trying to say is that it is very much a pre-market thing. It is important just for a safety aspect before anyone gets into any kind of man trials there is a completely unmanned validation. 

SIMON MITCHELL: Oskar, I am sympathetic to Kevin’s view there. This is not saying that there should not be manned testing. There should be unmanned testing with reporting of the results. As Kevin has outlined, I do not recall seeing informal reports of manned testing being publicly reported. Can you live with that? 

GAVIN ANTHONY: Can I offer clarification? You have got two separate things here. The first sentence is, “The forum endorses third-party testing to ensure it is fit for purpose.” That could be unmanned, manned, that could be everything. So make that bit generic. Now, the results that you are going to give are hard, numerical data, and I think that should come from the unmanned aspect because that takes out a lot of variability. 

SIMON MITCHELL: Nice suggestion.

MARTIN PARKER: I am not too happy on the “uniform suite of information.” Where are we going to get that uniformity from? Work of breathing, either you meet the standard or you do not. I would go for “canister duration and type of material” and I would take out “uniform suite.”

SIMON MITCHELL: These are just examples. I put “uniform suite” in because of a comment made during the discussion that it would be nice to know the same thing about every rebreather. So that when we line all the rebreathers up, we have got the same data. It is a goal. I would be happy to put “results of practically important manned testing” and take out “uniform suite.” Is there anyone who would object to me taking out “uniform suite?” There are a few. Is there anyone who would definitely like me to take out uniform suite other than Mr. Parker? Martin, I am sorry. 

NEAL POLLOCK: Can you solve it by putting it in the “ideally” section? 

SIMON MITCHELL: No. I think the view is pretty clear. 

MARTIN PARKER: If you are going to have a “uniform suite,” you better just agree here and now. 

SIMON MITCHELL: Have you guys just started an organization called Rebreather Education and Safety Association (RESA)? You can talk about it there. This is what this forum would like. It is not a mandate that you have to follow. It is endorsing a requirement for third-party testing and should be reported. We would like to know the same things about the units. 

JOHN CLARKE: Having an agreed universal standard is, in fact, a good thing. At least for the near future we will have US standards, we will not have the European standard. This would be a really brilliant idea, but I suspect it will be quite a while before we have a universal standard. 

SIMON MITCHELL: I am very reluctant to disagree with you. Was it your sense from the folks on your chair that people did or did not agree with a uniform standard? Because the sense I got is that there was a general view that a uniform standard is a good idea. 

JOHN CLARKE: I think the understanding is that there could be more than one standard. Certainly we care a lot about the European standards, but also as somebody indicated, they have to follow the US Navy standard as well. 

SIMON MITCHELL: Is there anybody who would object – I think what John is signaling here is that in the near future the United States of America might develop their own standard and who is to say that has to be the same as 14143; is that right? 

JOHN CLARKE: Right. Or who has to do the licensing or it could also be an ISO standard. 

SIMON MITCHELL: I will buy that argument. Is there anyone here who would object to me taking out that last sentence? 

MARTIN PARKER: How about going to “an internationally recognized standard.” 


MARTIN PARKER: I am still on the objection of work of breathing. The breathing effort consists of many issues. What I am worried about is people buying products just on numbers. You can have a slightly higher resistant workload, and overall perceived work of breathing. What I do not want people to do is buy products on the wrong numbers. So you are either meeting a European standard or you are not. You are either meeting it or you are not. 

SIMON MITCHELL: Martin, the alternative is no information, and I do not think this meeting is going to accept that. Does this make it any better for you “such as canister duration” and we can take out “type of material.” So “such as canister duration, work of breathing qualified by a clear statement of experimental parameters.” I do not think it is acceptable to this forum that we just say because people can function without reporting this, we accept them not reporting it at all. I think the feeling of the meeting is that people want to know these things. 

MARTIN PARKER: “Canister duration and material type” should be in there. “Work of breathing” should not. 

SIMON MITCHELL: I am going to put that one to a vote. 

OSKAR FRANBERG: If we are going to put examples we should have hydrostatic imbalance as well. 

SIMON MITCHELL: Shall I just take out these examples? 



SIMON MITCHELL: How many people would be happy for me to take these examples out? How many people do not want these examples taken out? It is the majority view. I am going to leave it there. 

PAUL HAYNES: By referencing these national standards by default you capture these things, do you not. 

SIMON MITCHELL: We are going to take a vote on this. I know there will be some objections to this. How many people in here object to this statement as it is currently worded? There are some objections. And how many people are in favor of this statement as it is currently worded? It is carried with a clear majority. 

This arises from Kevin Gurr’s survey data? “The forum acknowledges recent survey data indicating a poor understanding among trained users of rebreather operational limits in relation to depth and carbon dioxide scrubber durations and, therefore, recommends, one, that training organizations emphasize these parameters in training courses.” And two, that “Manufacturers display these parameters in places of prominence in device documentation and on websites.” We have to acknowledge the survey data. Is there anyone who disagrees with these statements in the current form? Carried unanimously.

The next statement speaks to Nigel’s outstanding presentation, in my view, this morning. “The forum strongly endorses industry initiatives to improve oxygen measurement technologies and advocates consideration of potentially beneficial emerging strategies such as dynamic validation of cell readings and alternatives to galvanic fuel cells.” Does anyone want to speak to this statement? No. We will take a vote. Is there anyone who disagrees with this statement as it is currently written? Carried unanimously.

This is a unique statement as the only one in which we are proposing a research question to the research community. This arose out of Paul Haynes’ advocacy for the use of gag straps. In fact, the resulting discussion made it clear that there was a lot of ambiguity around people’s perceptions. To my knowledge, there are no data or even substantial practical experience that answers that question for us. This statement says, “The forum identifies as a research question the issue of whether a mouthpiece retaining strap would provide protection of the airway in an unconscious diver.” We need to find a confident ethics committee or an imaginative way of figuring it out. Is there anyone that would like to speak to this? 

UNIDENTIFIED SPEAKER: Can we clear full face masks in that? 

SIMON MITCHELL: We have a statement about full face masks coming up next. 

PAUL RAYMAEKERS: I was not able to follow the presentation. I just hear that the question has no proof or any evidence that mouthpiece retaining strap has any efficiency. We did have a fatality a few years ago where it was clearly proven that when the jaw stress completely falls away a correctly attached gag strap keeps the mouthpiece in place and no water comes in the diver’s lungs. 

SIMON MITCHELL: If I am interpreting correctly saying there, there has been a case that you know of with a gag strap and mouthpiece in place. John, do you want to speak to this? 

JOHN CLARKE: I think research would include looking at prior history. One case does not mean this has been solved. 

OSKAR FRANBERG: We come from the military community. I think that if we look at our own data from the fatalities, we may find information on the presence or absence of water in the airway. 

SIMON MITCHELL: I like that idea. So what we need is someone who has perhaps a Naval group with keen, young, research-hungry doctors who can start phoning up every Navy in the world. My tongue is in my cheek if I have got a smile on my face. I think there probably may be enough information out there already to form this debate. We have just got to find it. It would be great to have that reported. If someone could compile the cases and report them, I think that would be a pretty powerful case. Is there anyone who objects to this statement in its current form? Carried as unanimously. 

The next statement was a result for John’s focus group. “The forum recommends that industry and divers interact with the goal of optimizing a full face mask for use with rebreathers.” This is largely on the basis that a full face mask presents a lot of advantages in terms of airway protection. As was mentioned in a number of discussions, there are disadvantages that come with them also, particularly in the realm of rebreather technical diving, and the need for gas switches and in some cases multiple gas switches. 

JILL HEINERTH: Unfortunately, this was one of the sessions where we did not have the opportunity for feedback and questions and comments at the end. So I do not know if there was clear consensus. 

SIMON MITCHELL: If you want to say something, say it now. 

JILL HEINERTH: Just that there are many other issues and perhaps this could be worded in a way similar to the last question. It is a research question because there are many downsides to full face masks that need to be examined as well, such as they are not designed for closed-circuit, introduce new failure points, morbidity issues, CO2 buildup, need for extra gas for flushing, need for training for clearing. There are a lot of things that need to be studied. 

SIMON MITCHELL: John, would you have any objection to me rewording this into a research question? 

GAVIN ANTHONY: In response to Jill, the military has addressed this over the years. So recommending how to move that technology into more universal aspect is good. Either recommend or make it a research aspect. 

TOM MOUNT: I am going to make a comment based on some personal experience. We had a canister break loose at 20 m (66 ft) with a full face mask. I had to come up, get the open-circuit mouthpiece, and try to keep water in the loop under control. I do not think training rebreather divers on the full face is a necessary process. 

UNIDENTIFIED SPEAKER: I was thinking adding appropriate training if you are going to use a full face mask. 

SIMON MITCHELL: I do not have any difficulty with an issue for which training is critically important. What we are really getting at here is whether a full face mask as a concept is a good thing. If we accept that it is a good thing, then training is clearly critical. But the spirit is really trying to get a sense of whether we should be saying to rebreather divers that full face masks are a good thing for rebreather diving. I think we are one step back from talking about the training. It is a bit like the gag strap question. We are trying to decide whether these were a good idea or not. 

UNIDENTIFIED SPEAKER: The “optimizing” not just the full face mask itself, but the practices of the closed-circuit divers. 

SIMON MITCHELL: I think I might take “optimizing” out because that has the expectation of a positive outcome about it. The goal of establishing feasibility is what I am thinking of. 

RICHARD WALKER: I agree wholeheartedly with Jill on this. With respect to our military colleagues we do use this equipment in a substantially different way. I am not aware of any evidence to prove that in the manner that we use this equipment, a full face mask offers a clear safety advantage. That would need to be established first. And once that is established or if that is established, we can move on to the need to develop a product. But I would support more of a research focus on this to look at whether or not we are sure before we suggest that a full face mask does offer more advantages than disadvantages in the way we use rebreathers. 

SIMON MITCHELL: I am going to change this to the same sort of style as we had before. So, “The forum identifies as a research question the feasibility of a full face mask for use with rebreathers.”

NEAL POLLOCK: Should that be “efficacy” rather than “feasibility?” We know it is feasible. 

SIMON MITCHELL: Yes, you are right, as usual, when it comes to wordsmithing issues. 

TERRENCE ADAMS: I am going to fall in line with Tom and Jill on this one. I think for us to recommend the use of a particular thing we have to remember the famous open-circuit debate we had on this topic 15 or 20 years ago. 

SIMON MITCHELL: I am completely happy with that, and I think that phrasing it this way puts a very cautionary tone on the whole issue of full face masks in rebreather diving. 

TERRENCE ADAMS: I want to keep that ability to be able to deny that. 

GARETH LOCK: You might solve that by adding “sport” or “recreational.” We know the military have processes for that. 

SIMON MITCHELL: I think this is one case where it is reasonable to distinguish between military and recreational. 


UNIDENTIFIED SPEAKER: I think we are still flirting a little bit on that knife edge with a lot of opinion here. I think it is a really worthwhile thing to look into. We have been diving 20 or 30 years with full face masks. We love the ability to use communications. 

SIMON MITCHELL: I do not think there is any suggestion that they can be appropriate in some circumstances. It is just that it is a thing that we recommend for recreational sport rebreathers in general. The sense I am getting from the forum is this is something we would like more engagement with the people who know how to use them before we move forward with this. Now we have got one more very important statement to do. This reads, “The forum identifies as a research question the efficacy of full face mask for use with sport rebreathers.” Is there anyone who objects to this in its current form? 

UNIDENTIFIED SPEAKER: Efficacy does not mean anything. 

SIMON MITCHELL: It does. It is basically saying that there has been a discussion at this forum that gives a sense that they are not something that we think are generalizable across the rebreather diving community and that we need more information, experience with it. Anyway, the vote has been taken. 

This is one that is important and potentially controversial. “The forum recognizes and endorses the industry and training agency initiative to characterize recreational and technical streams of rebreather diver training. These groups will have different working envelopes, training and equipment needs.” This was discussed quite a lot in the last session that was chaired by Phil and Jill. Is there anyone who would like to speak to this? Is there anyone who objects to the concept?

STEVE LEWIS: I think that we have already established that what everyone does here is not military, scientific, or commercial. So we are doing recreational diving, and recreational diving kind of falls into sport diving and technical diving. It is not a big point, but everyone else has been nitpicking so I figured I had better do it. 

SIMON MITCHELL: Who are you speaking about in particular? I think the reason for this statement is that these are terms that are going to be brought higher and higher in our consciousness by the training organizations and the manufacturers. This is a route that they want to go down and a distinction that they want to make. It is been raised here a number of times and this is essentially a recognition of it. 

RICHARD WALKER: Can we pull the word “working” out and change it to “operational” so we stay away from that whole OSHA, military, scientific issue. 

SIMON MITCHELL: “Different operational.” Mark Caney, do you want to say anything about this? 

MARK CANEY: I like it. 

TOM MOUNT: I have a question here. Who would these working groups be? Would they be the training agencies themselves and the manufacturers? 

SIMON MITCHELL: We are referring to the groups of divers, so recreational divers and technical divers will have different operational, training and equipment needs. We heard in the previous session that there was a defined set of parameters. 

TOM MOUNT: Sorry, I misunderstood the statement. 

RICHARD HARRIS: Do you want to put “sport rebreather diver training?” 

SIMON MITCHELL: Anyone else want to speak to this statement? 

GAVIN ANTHONY: I have one concern with this, and it is a safety concern. That is the fact that the macho aspect will force people to say, “I want to be technical. I want to go down that route.” I think there is much more of a sliding scale. You do not go up to a point as recreational and then suddenly flip to being technical. You can progress slowly through that. I think there is a safety concern here that you may inadvertently push people to do things that they do not want to because you put certain names there. 

SIMON MITCHELL: Jill, do you want to speak to that? 

JILL HEINERTH: I would suggest that this statement does the exact opposite. That it recognizes that particular equipment is good for particular types of diving. In the recreational envelope, “I have got a problem, therefore, I bailout and go to the surface.” That equipment should not allow for a sliding scale between those two entities. I like the statement. 

DALE BLETSO: I think all the training agencies are doing that naturally. They have got recreational training and technical training. 

SIMON MITCHELL: As I have pointed out, this is kind of one of those statements of the obvious, but this is the first rebreather forum we have had since that distinction was made, and hence, the desire for the statement to be made. I think that is specific terminology that is being proposed as technical. Is that correct, Mark? 

MARK CANEY: Yes, there are. I think within the sport diving community there is a distinct understanding of the terms recreational and technical so this is a good definition as it stands. 

ANDREW FOCH: What exactly do you mean by endorses? 

SIMON MITCHELL: That we agree with it. We do not think it is a bad idea. So presumably this might be a unanimous decision then. 

ANDREW FOCK: We will see. 

BARRY COLEMAN: There may be a question with regard to what is technical with sport rebreathers. Some may claim that if you are on a rebreather and bailing out to a side cylinder that is technical. Are we taking the recreational and technical from the open-circuit and trying to apply it to rebreather diving where there could be arguments that this is technical in itself, bailing out, whether you are bailing out to turning a switch on the mouthpiece or you are actually bailing out to a side cylinder. Could there be a problem with any of this? 

SIMON MITCHELL: I do not know if any of the people from the training and operations forum want to speak to that, but my understanding is that there is a very specific definition of what recreational rebreather is and that definition was displayed during the session. I do not have it here, but there is a set of criteria that defines recreational as distinct from technical. Would you like to speak to that, Mark or Jill? 

MARK CANEY: Yes. Again, I would say there is a fairly clear understanding of what these two things are. I think the important thing about this statement is it is recognizing the fact that now as opposed to when we had the last one of these forums there is such a thing as a recreational rebreather user as opposed to what we call a technical rebreather user. And this committee recognizes that delineation and the fact that they have different operating envelopes and different needs. 

SIMON MITCHELL: I think we will call that discussion closed now. And I am going to ask for all those who disagree with this statement in its present form to put up their hands. So there are some, but it is a clear minority. So that statement is adopted by a clear majority. That is the end of the session. I congratulate this forum on a remarkably mature discussion completely absent of vitriolic abuse and other forms of negative argument. I think it has been a fabulous event. I would like to offer my thanks once more to the organizing organizations. 

MARTIN PARKER: Just one question. I brought the subject up about solo diving and diving with a buddy, and it seems like we are not going to get an idea from this forum, but can we show hands up who agrees that rebreather diving should be done in pairs? Show of hands, please. Pairs or teams. Please put your hands down. Everybody who thinks that rebreather diving should be done solo. 

  • Area 9
  • Halcyon Sidemount
  • Subscribe for free


MARTIN PARKER: “Rebreather diving could be done solo.” Thank you. Do you think that is worth putting up there as a motion? 

SIMON MITCHELL: It is probably too late now. But, for the record, what we just showed there is that a clear majority of the participants of the forum indicated a preference for buddy diving when using a rebreather, but it is also clear that a significant portion of the forum participants believe that you can dive solo but not necessarily that you should dive solo. That would be my interpretation. 

RICHARD VANN: It remains for me to close the meeting, which I will do shortly. On behalf of AAUS, DAN, PADI, a few more acknowledgments. We appreciate the critical support of PADI personnel, Dawn Azua, Adrianne Miller, Janelle Hamm, Dan Machum, Tom Hedlick, and Nicole Sherman. Similarly, from DAN and Duke, Jenna Wiley, Mitch Mackey, Gene Hobbs and Dr. Dawn Kernagis. These individuals kept all of the rooms running smoothly. We also thank Kim Farkas for recording notes and Roz Lunn for organizing the venue. Finally, thank you all for your active participation. Rebreather Forum 3.0 is now closed. 


Twenty-five Years in the Pursuit of Excellence – The Evolution and Future of GUE

Founder and president Jarrod Jablonski describes his more than a quarter of a century long quest to promote excellence in technical diving.




by Jarrod Jablonski. Images courtesy of J. Jablonski and GUE unless noted.

The most difficult challenges we confront in our lives are the most formative and are instrumental in shaping the person we become. When I founded Global Underwater Explorers (GUE), the younger version of myself could not have foreseen all the challenges I would face, but equally true is that he would not have known the joy, the cherished relationships, the sense of purpose, the rich adventures, the humbling expressions of appreciation from those impacted, or the satisfaction of seeing the organization evolve and reshape our industry. Many kindred souls and extraordinary events have shaped these last 25 years, and an annotated chronology of GUE is included in this issue of InDEPTH. This timeline, however, will fail to capture the heart behind the creation of GUE, it will miss the passionate determination currently directing GUE, or the committed dedication ready to guide the next 25 years.

Photo courtesy of Kirill Egorov

I don’t remember a time that I was not in, around, and under the water. Having learned to swim before I could walk, my mother helped infuse a deep connection to the aquatic world. I was scuba certified in South Florida with my father, and promptly took all our gear to North Florida where I became a dive instructor at the University of Florida. It was then that I began my infatuation with cave diving. I was in the perfect place for it, and my insatiable curiosity was multiplied while exploring new environments. I found myself with a strong desire to visit unique and hard-to-reach places, be they far inside a cave or deep within the ocean. 

My enthusiasm for learning was pressed into service as an educator, and I became enamored with sharing these special environments. Along with this desire to share the beauty and uniqueness of underwater caves was a focused wish to assist people in acquiring the skills I could see they needed to support their personal diving goals. It could be said that these early experiences were the seeds that would germinate, grow, mature, and bloom into the organizing principles for GUE.

Brent Scarabin, Jarrod and George “Trey” Irvine getting ready to dive.
Jarrod with his Halcyon PVR-BASC prototype.
George Irvine and Jarrod conducting the original DIR workshop.

The Pre-GUE Years

Before jumping into the formational days of GUE, allow me to help you visualize the environment that was the incubator for the idea that became GUE’s reality. By the mid-1990s, I was deeply involved in a variety of exploration activities and had been striving to refine my own teaching capacity alongside this growing obsession for exploratory diving. While teaching my open water students, I was in the habit of practicing to refine my own trim and buoyancy, noticing that the students quickly progressed and were mostly able to copy my position in the water. Rather than jump immediately into the skills that were prescribed, I started to take more time to refine their comfort and general competency. This subtle shift made a world of difference in the training outcomes, creating impressive divers with only slightly more time and a shift in focus. In fact, the local dive boats would often stare in disbelief when told these divers were freshly certified, saying they looked better than most open water instructors! 

Area 9

By this point in my career, I could see the problems I was confronting were more systemic and less individualistic. In retrospect, it seemed obvious that key principles had been missing in both my recreational and technical education, not to mention the instructor training I received. The lack of basic skill refinement seemed to occur at all levels of training, from the beginner to the advanced diver. Core skills like buoyancy or in-water control were mainly left for divers to figure out on their own and almost nobody had a meaningful emphasis on efficient movement in the water. It was nearly unheard of to fail people in scuba diving, and even delaying certification for people with weak skills was very unusual. This remains all too common to this day, but I believe GUE has shifted the focus in important ways, encouraging people to think of certification more as a process and less as a right granted to them because they paid for training. 

L2R: Jarrod Todd Kincaid and Rickard Lundgren plotting their 1999 Britannic expedition.

The weakness in skill refinement during dive training was further amplified by little-to-no training in how to handle problems when they developed while diving, as they always do. In those days, even technical/cave training had very little in the way of realistic training in problem resolution. The rare practice of failures was deeply disconnected from reality. For example, there was almost no realistic scenario training for things like a failed regulator or light. What little practice there was wasn’t integrated into the actual dive and seemed largely useless in preparing for real problems. I began testing some of my students with mock equipment failures, and I was shocked at how poorly even the best students performed. They were able to quickly develop the needed skills, but seeing how badly most handled their first attempts left me troubled about the response of most certified divers should they experience problems while diving, as they inevitably would. 

Diving Fatalities

Meanwhile, I was surrounded by a continual progression of diving fatalities, and most appeared entirely preventable. The loss of dear friends and close associates had a deep impact on my view of dive training and especially on the procedures being emphasized at that time within the community. The industry, in those early days, was wholly focused on deep air and solo diving. However, alarmingly lacking were clear bottle marking or gas switching protocols. It seemed to me to be no coincidence that diver after diver lost their lives simply because they breathed the wrong bottle at depth. Many others died mysteriously during solo dives or while deep diving with air. 

One of the more impactful fatalities was Bob McGuire, who was a drill sergeant, friend, and occasional dive buddy. He was normally very careful and focused. One day a small problem with one regulator caused him to switch regulators before getting in the water. He was using a system that used color-coded regulators to identify the gas breathed. When switching the broken regulator, he either did not remember or did not have an appropriately colored regulator. This small mistake cost him his life. I clearly remember turning that one around in my head quite a bit. Something that trivial should not result in the loss of a life. 

Also disturbing was the double fatality of good friends, Chris and Chrissy Rouse, who lost their lives while diving a German U-boat in 70 m/230 ft of water off the coast of New Jersey. I remember, as if the conversation with Chris were yesterday, asking him not to use air and even offering to support the cost as a counter to his argument about the cost of helium. And the tragedies continued: The loss of one of my closest friends Sherwood Schille, the death of my friend Steve Berman who lived next to me and with whom I had dived hundreds of times, the shock of losing pioneering explorer Sheck Exley, the regular stream of tech divers, and the half dozen body recoveries I made over only a couple years, which not only saddened me greatly, but also made me angry. Clearly, a radically different approach was needed.

  • Area 9

Learning to Explore

Meanwhile, my own exploration activities were expanding rapidly. Our teams were seeking every opportunity to grow their capability while reducing unnecessary risk. To that end, we ceased deep air diving and instituted a series of common protocols with standardized equipment configurations, both of which showed great promise in expanding safety, efficiency, and comfort. We got a lot of things wrong and experienced enough near misses to keep us sharp and in search of continual improvement. 

Casey McKinlay and Jarrod with stages and Gavin scooters in Wakulla Springs. Photo courtesy of David Rhea

But we looked carefully at every aspect of our diving, seeking ways to advance safety, efficiency, and all-around competency while focusing plenty of attention into the uncommon practice of large-scale, team diving, utilizing setup dives, safety divers, and inwater support. We developed diver propulsion vehicle (DPV) towing techniques, which is something that had not been done previously. We mostly ignored and then rewrote CNS oxygen toxicity calculations, developed novel strategies for calculating decompression time, and created and refined standard procedures for everything from bottle switching to equipment configurations. Many of these developments arose from simple necessity. There were no available decompression programs and no decompression tables available for the dives we were doing. Commonly used calculations designed to reduce the risk of oxygen toxicity were useless to our teams, because even our more casual dives were 10, 20, or even 30 times the allowable limit. The industry today takes most of this for granted, but in the early days of technical diving, we had very few tools, save a deep motivation to go where no one had gone before.

All in a dive of diving for the WKPP.

Many of these adventures included friends in the Woodville Karst Plain Project (WKPP), where I refined policies within the team and most directly with longtime dive buddy George Irvine. This “Doing it Right” (DIR) approach sought to create a more expansive system than Hogarthian diving, which itself had been born in the early years of the WKPP and was named after William Hogarth Main, a friend and frequent dive buddy of the time. By this point, I had been writing about and expanding upon Hogarthian diving for many years. More and more of the ideas we wanted to develop were not Bill Main’s priorities and lumping them into his namesake became impractical, especially given all the debate within the community over what was and was not Hogarthian. 

A similar move from DIR occurred some years later when GUE stepped away from the circular debates that sought to explain DIR and embraced a GUE configuration with standard protocols, something entirely within our scope to define.

These accumulating events reached critical mass in 1998. I had experienced strong resistance to any form of standardization, even having been asked to join a special meeting of the board of directors (BOD) for a prominent cave diving agency. Their intention was to discourage me from using any form of standard configuration, claiming that students should be allowed to do whatever they “felt’ was best. It was disconcerting for me, as a young instructor, to be challenged by pioneers in the sport; nevertheless, I couldn’t agree with the edict that someone who was doing something for the first time should be tasked with determining how it should be done. 

This sort of discussion was common, but the final straw occurred when I was approached by the head of a technical diving agency, an organization for which I had taught for many years. I was informed that he considered it a violation of standards not to teach air to a depth of at least 57 m/190 ft. This same individual told me that I had to stop using MOD bottle markings and fall in line with the other practices endorsed by his agency. Push had finally come to shove, and I set out to legitimize the training methods and dive protocols that had been incubating in my mind and refined with our teams over the previous decade. Years of trial and many errors while operating in dynamic and challenging environments were helping us to identify what practices were most successful in support of excellence, safety, and enjoyment.

Forming GUE

Forming GUE as a non-profit company was intended to neutralize the profit motivations that appeared to plague other agencies. We hoped to remove the incentive to train—and certify—the greatest number of divers as quickly as possible because it seemed at odds with ensuring comfortable and capable divers. The absence of a profit motive complemented the aspirational plans that longtime friend Todd Kincaid and I had dreamed of. We imagined a global organization that would facilitate the efforts of underwater explorers while supporting scientific research and conservation initiatives. 

I hoped to create an agency that placed most of the revenue in the hands of fully engaged and enthusiastic instructors, allowing them the chance to earn a good living and become professionals who might stay within the industry over many years. Of course, that required forgoing the personal benefit of ownership and reduced the revenue available to the agency, braking its growth and complicating expansion plans. This not only slowed growth but provided huge challenges in developing a proper support network while creating the agency I envisioned. There were years of stressful days and nights because of the need to forgo compensation and the deep dependance upon generous volunteers who had to fit GUE into their busy lives. If it were not for these individuals and our loyal members, we would likely never have been successful. Volunteer support and GUE membership have been and remain critical to the growing success of our agency. If you are now or have ever been a volunteer or GUE member, your contribution is a significant part of our success, and we thank you. 

Photo courtesy of Kirill Egorov

The challenges of the early years gave way to steady progress—always slower than desired, with ups and downs, but progress, nonetheless. Some challenges were not obvious at the outset. For example, many regions around the world were very poorly developed in technical diving. Agencies intent on growth seemed to ignore that problem, choosing whoever was available, and regardless of their experience in the discipline, they would soon be teaching. 

This decision to promote people with limited experience became especially problematic when it came to Instructor Trainers. People with almost no experience in something like trimix diving were qualifying trimix instructors. Watching this play out in agency after agency, and on continent after continent, was a troubling affair. Conversely, it took many years for GUE to develop and train people of appropriate experience, especially when looking to critical roles, including high-level tech and instructor trainers. At the same time, GUE’s efforts shaped the industry in no small fashion as agencies began to model their programs after GUE’s training protocols. Initially, having insisted that nobody would take something like Fundamentals, every agency followed suit in developing their own version of these programs, usually taught by divers that had followed GUE training. 

This evolving trend wasn’t without complexity but was largely a positive outcome. Agencies soon focused on fundamental skills, incorporated some form of problem-resolution training, adhered to GUE bottle and gas switching protocols, reduced insistence on deep air, and started talking more about developing skilled divers, among other changes. This evolution was significant when compared to the days of arguing about why a person could not learn to use trimix until they were good while diving deep on air. 

To be sure, a good share of these changes was more about maintaining business relevance than making substantive improvements. The changes themselves were often more style than substance, lacking objective performance standards and the appropriate retraining of instructors. Despite these weaknesses, they remain positive developments. Talking about something is an important first step and, in all cases, it makes room for strong instructors in any given agency to practice what is being preached. In fact, these evolving trends have allowed GUE to now push further in the effort to create skilled and experienced divers, enhancing our ability to run progressively more elaborate projects with increasingly more sophisticated outcomes. 

  • Halcyon Sidemount

The Future of GUE

The coming decades of GUE’s future appear very bright. Slow but steady growth has now placed the organization in a position to make wise investments, ensuring a vibrant and integrated approach. Meanwhile, evolving technology and a broad global base place GUE in a unique and formidable position. Key structural and personnel adjustments complement a growing range of virtual tools, enabling our diverse communities and representatives to collaborate and advance projects in a way that, prior to now, was not possible. Strong local communities can be easily connected with coordinated global missions; these activities include ever-more- sophisticated underwater initiatives as well as structural changes within the GUE ecosystem. One such forward-thinking project leverages AI-enabled, adaptive learning platforms to enhance both the quality and efficiency of GUE education. Most agencies, including GUE, have been using some form of online training for years, but GUE is taking big steps to reinvent the quality and efficiency of this form of training. This is not to replace, but rather to extend and augment inwater and in-person learning outcomes. Related tools further improve the fluidity, allowing GUE to seamlessly connect previously distant communities, enabling technology, training, and passion to notably expand our ability to realize our broad, global mission.

Photo courtesy of Kirill Egorov

Meanwhile, GUE and its range of global communities are utilizing evolving technologies to significantly expand the quality and scope of their project initiatives. Comparing the impressive capability of current GUE communities with those of our early years shows a radical and important shift, allowing results equal or even well beyond those possible when compared even with well-funded commercial projects. Coupled with GUE training and procedural support, these ongoing augmentations place our communities at the forefront of underwater research and conservation. This situation will only expand and be further enriched with the use of evolving technology and closely linked communities. Recent and planned expansions to our training programs present a host of important tools that will continue being refined in the years to come. Efforts to expand and improve upon the support provided to GUE projects with technology, people, and resources are now coming online and will undoubtedly be an important part of our evolving future.

The coming decades will undoubtedly present challenges. But I have no doubt that together we will not only overcome those obstacles but we will continue to thrive. I believe that GUE’s trajectory remains overwhelmingly positive, for we are an organization that is continually evolving—driven by a spirit of adventure, encouraged by your heartwarming stories, and inspired by the satisfaction of overcoming complex problems. Twenty-five years ago, when I took the path less traveled, the vision I had for GUE was admittedly ambitious. The reality, however, has exceeded anything I could have imagined. I know that GUE will never reach a point when it is complete but that it will be an exciting lifelong journey, one that, for me, will define a life well lived. I look forward our mutual ongoing “Quest for Excellence.”

See Listings Below For Additional Resources On GUE And GUE Diving!

Jarrod is an avid explorer, researcher, author, and instructor who teaches and dives in oceans and caves around the world. Trained as a geologist, Jarrod is the founder and president of GUE and CEO of Halcyon and Extreme Exposure while remaining active in conservation, exploration, and filming projects worldwide. His explorations regularly place him in the most remote locations in the world, including numerous world record cave dives with total immersions near 30 hours. Jarrod is also an author with dozens of publications, including three books.

A Few GUE Fundamentals

Similar to military, commercial and public safety divers, Global Underwater Explorers (GUE) is a standards-based diving community, with specific protocols, standard operating procedures (SOPs) and tools. Here are selected InDEPTH stories on some of the key aspects of GUE diving, including a four-part series on the history and development of GUE decompression procedures by founder and president Jarod Jablonski.

Anatomy of a Fundamentals Class

GUE Instructor Examiner Guy Shockey explains the thought and details that goes into GUE’s most popular course, Fundamentals, aka “Fundies,” which has been taken by numerous industry luminaries. Why all the fanfare? Shockey characterizes the magic as “simple things done precisely!

Back to Fundamentals: An Introduction to GUE’s Most Popular Diving Course

Instructor evaluator Rich Walker attempts to answer the question, “why is Fundamentals GUE’s most popular diving course?” Along the way, he clarifies some of the myths and misconceptions about GUE training. Hint: there is no Kool-Aid. 

The GUE Pre-dive Sequence

As you’d expect, Global Underwater Explorers (GUE) has a standardized approach to prepare your equipment for the dive, and its own pre-dive checklist: the GUE EDGE. Here explorer and filmmaker Dimitris Fifis preps you to take the plunge, GUE-style.

The Flexibility of Standard Operating Procedures

Instructor trainer Guy Shockey discusses the purpose, value, and yes, flexibility of standard operating procedures, or SOPs, in diving. Sound like an oxymoron? Shockey explains how SOPs can help offload some of our internal processing and situational awareness, so we can focus on the important part of the dive—having FUN!

Standard Gases: The Simplicity of Everyone Singing the Same Song

Like the military and commercial diving communities before them, Global Underwater Explorers (GUE) uses standardized breathing mixtures for various depth ranges and for decompression. Here British wrecker and instructor evaluator Rich Walker gets lyrical and presents the reasoning behind standard mixes and their advantages, compared with a “best mix” approach. Don’t worry, you won’t need your hymnal, though Walker may have you singing some blues.

Rules of Thumb: The Mysteries of Ratio Deco Revealed

Is it a secret algorithm developed by the WKPP to get you out of the water faster sans DCI, or an unsubstantiated decompression speculation promoted by Kool-Aid swilling quacks and charlatans? British tech instructor/instructor evaluator Rich Walker divulges the arcane mysteries behind GUE’s ratio decompression protocols in this first of a two part series.

The Thought Process Behind GUE’s CCR Configuration

Global Underwater Explorers is known for taking its own holistic approach to gear configuration. Here GUE board member and Instructor Trainer Richard Lundgren explains the reasoning behind its unique closed-circuit rebreather configuration. It’s all about the gas!

GUE and the Future of Open Circuit Tech Diving

Though they were late to the party, Global Underwater Explorers (GUE) is leaning forward on rebreathers, and members are following suit. So what’s to become of their open circuit-based TECH 2 course? InDepth’s Ashley Stewart has the deets.

Project Divers Are We

Diving projects, or expeditions—think Bill Stone’s Wakulla Springs 1987 project, or the original explorations of the Woodville Karst Plain’s Project (WKPP)—helped give birth to technical diving, and today continue as an important focal point and organizing principle for communities like Global Underwater Explorers (GUE). The organization this year unveiled a new Project Diver program, intended to elevate “community-led project dives to an entirely new level of sophistication.” Here, authors Guy Shockey and Francesco Cameli discuss the power of projects and take us behind the scenes of the new program

Decompression, Deep Stops and the Pursuit of Precision in a Complex World In this first of a four-part series, Global Underwater Explorers’ (GUE) founder and president Jarrod Jablonski explores the historical development of GUE decompression protocols, with a focus on technical diving and the evolving trends in decompression research.

  • Subscribe for free
  • Halcyon Sidemount
  • Area 9
Continue Reading


WordPress PopUp Plugin