The final word from my new book…

This has been a poor year for diver deaths. I have just wrapped up a book called Staying Alive and it’s about risk management for divers… I started it because of a couple of regrettable incidents and as I finished it three months later, more deaths. The book is scheduled for launch next month from Amazon and CreateSpace. Here are my closing remarks.
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IN CLOSING
Perception of risk changes over time. The more successful we are at beating the odds, the less risky we take our behavior to be; and of course, the opposite may be true. Too often, luck reinforces bad decisions and dilutes fear, and fear is surely part of the apparatus, our personal filter, for risk management. We each must understand that because someone surfaces from a dive with a smile on their face, it does not mean they follow a good risk management process or that their behavior is not risky. It is impossible to measure a negative. Vigilance is required.

I am sitting in my office wrapping up this project. There is snow on the ground outside and I will soon have to pack and get ready to fly to Europe and go to yet another interesting and very big dive show. Perhaps I should feel happy, but I do not: I am sad.

Yesterday evening I got news that a father and son (a boy of 15 who had earned no level of scuba certification at all) had both drowned in the Eagles Nest Cave, an advanced-level North Florida system considered a challenge to certified and experienced trimix cave divers. They were, according to family, testing out new gear the kid had been given for Christmas. What on earth were they thinking: what was the father thinking as he died? Last week, two more technical divers perished. One in the Red Sea and one in the caves of Mexico. I knew them both. One much better than the other but both were nice guys; both were experienced, and unlike the father/son combination who died in a spot where neither belonged, both of last week’s victims were what one would call careful divers.

Fatal dive accidents frequently have multiple and complex, often interconnected, root causes. While each accident has unique qualities about it – in part because of the individuals involved – most accidents can be characterized as a chain of small events that lead to disaster.
This chain of events very often starts with a minor challenge – a failure in communications, a broken strap – and one event meshes with a deficiency or mistake elsewhere and triggers something even more serious, and this in turn results in escalating calamities until the house of cards has fallen down completely. To stay on top of things, technical divers need to become pretty slick at recognizing problems early, preventing a chain reaction, and thereby avoiding a one-way ride to calamity. Often something as simple as calling a dive early, before anyone gets close to the edge, can change the outcome radically and turn a potentially nasty epiphany into a positive learning experience.

Gareth Lock, who was kind enough to write the foreword for this book, is a Royal Air Force officer with a background in risk analysis and management. In his writings and presentations, he shares with us a refreshingly analytical view of dive accidents.

He and I arrive at a similar destination via quite different analytical pathways. Based on his background in the military, he uses what he calls the HFACS Dive model (pronounced H – FACS-D). His analysis and methods are based on the Human Factors Analysis and Classification System framework developed by Dr. Douglas Wiegmann and Dr. Scott Shappell of the United States Navy to identify why accidents happen and how to reduce their impact and frequency. Gareth suggests that for a dive accident to occur, several contributing factors have to align. These factors may include organizational influence, unsafe supervision, a pre-condition for unsafe acts, and unsafe acts themselves.

I believe the factors, the triggers, that lead to deaths like the recent ones in a Florida cave, the Red Sea, and Mexico are more personal, more within our grasp. The eight triggers identified back in the 1990s: Attitude, Knowledge, Training, Gas Supply, Gas Toxicity, Exposure, Equipment and Operations, provide divers with a laundry list of potential dangers.

Gareth points out with some clarity, that people ‘get away’ with diving ‘successfully’ when there are errors at every level in his HFACS model: they simply did not align that day. “And that,” he tells us. “Reinforces bad decisions and creates diver complacency.”

One has to agree with him regardless of how or why you feel divers are dying so frequently. It seems that ignoring just one of the eight risk triggers may be enough to begin a series of events that end in death: it may take two or three, and a lucky diver may get away with ignoring four or five without an incident. Life is not fair that way.

Finally, Gareth reminds us: “It is easy to blame a person, when the system is actually at fault.”
I believe too that we are sometimes too quick to blame the individual and often do not trace the mistakes made back to their “systemic” roots, but sometimes all the fault does rest with one person. The system did its best and the best is all we can expect of anything outside of a nanny state. In some instances, the buck comes to a full stop up against the victim’s attitude, their ignorance, their lack of training, their history of flaunting the rules, their willingness to gamble with the odds.

Every day you and I, indeed the whole diving community, are faced with a dilemma: error of omission or error of commission. In cases where we know someone is pushing their luck, do we mind our own business, remain quiet and watch as they hurt themselves or their dive buddies; or do we speak out? If we are part of a system that Gareth and others say needs fixing, do we have the tools to carry out the repairs? Do we even know what to fix and where to start? Can we make a difference?

There’s a kid throwing starfish back into the sea as the tide recedes. A guy walks up and asks him what he’s up to. “Saving lives,” he explains. “The tide is going out and these starfish will die on the beach, so I’m throwing them back in.” The man laughs and tells the kid that the beach is miles long and that there are hundreds, probably thousands of stranded starfish. He tells the kid he can’t save them all. The kid stops what he’s doing, looks at the guy, looks up at the sky, and back out at the ocean. He bends down, picks up another starfish and throws it as far out to sea as he can. “Saved that one!”

My hope is that through all this effort, I may just get one person to think twice before starting a dive with a faulty oxygen cell, or breathing a gas that hasn’t been analyzed, or dismissing a buddy’s suggestion that today is not a good day to go diving or taking an unqualified diver to a trimix depth cave to test new gear. Help me save a starfish.

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USING ADDITIONAL REDUNDANCY: the maligned and misunderstood pony bottle

This is a short extract from a book on risk management that we hope to have finished next month.

 

I would guess that most dive instructors, especially those who teach technical programs, get regular requests from divers to explain how to “use” a pony bottle, how to configure it so it’s not in the way, and which size pony bottle is “right” for them.
These are great questions because any diver who intends to dive deeper than 30 metres /100 feet should carry a redundant source of gas. A dive buddy is supposed to represent the first line of backup, and a well-trained and well-practiced buddy is a great resource in the event of some major gas emergency. However, the best strategy is that whenever practical strive to have a backup for your backup. In this regard, redundant air via a redundant delivery system offers a huge cushion.
The question of size is perhaps the first question to answer because how to rig and use a pony bottle depends to a large extent on its size.
When we consider using a pony bottle as a bailout or as a backup in the event of a massive gas failure with our “primary system” (the normal tank and regulator), we factor in a full minute at maximum depth to get things sorted and to gather our wits before starting the ascent. With this in mind, let’s revisit the table for SAC adjusted for depth. Since we are still talking about recreational sport diving, the limit for maximum depth is around 40 metres or 132 feet. The ambient pressure at this depth is five bar or ata and therefore the average per minute consumption will be 70 litres or 2.5 cubic feet.

Let’s also apply a realistic dive factor. Since a pony bottle is only deployed in times of stress, we need to use a DF for that first minute that reflects high-stress. The norm for this application is a DF of 2.5, which translates into 175 litres or 6.25 cubic feet for that critical first minute!
(If at this point you are beginning to question the veracity of ads extoling the virtues of those tiny emergency cylinders of “spare” compressed air, please read on.)
After the first minute, we calculate a normal ascent rate (9 metres or 30 feet per minute) up to a safety stop. That journey – about 35 metres/ 117 feet – will take about four minutes. Once again, to help simplify the calculations, we use the ambient pressure at the midpoint between maximum depth and the safety stop, which in this case will be 3.22 bar or ata. We also drop the DF to 2.0. So we have ascent time X SAC X ambient pressure X DF, which equals 360 litres or about 13 cubic feet of gas.
Now for the safety stop. Even when a dive is within the no decompression limits, there is a strong suggestion from most experts that a five-minute stop is indicated after a dive to maximum depth. So the consumption for a five-minute stop at 4.5 metres or 15 feet with a mild DF of 1.2 adds up to a total of 122 litres or 4.35 cubic feet. Finally we have to factor in a little gas for the last part of the ascent to the surface. Therefore, the best estimate is that a controlled ascent following an emergency at depth will require at least 680 litres or close to 25 cubic feet of breathable gas!
It’s the considered opinion of most divers who have experienced a real gas emergency at depth in real-world dive conditions that these numbers are neither exaggerated nor inflated. When something bad happens at great depth, there is no such thing as a plan that is too conservative or too careful. The risks of drowning, embolism, decompression sickness and various other ailments that can result from stark panic and ballistic ascents are very real and totally unforgiving. The alternative to a controlled normal ascent are simply not worth considering.
Clearly then, the “right” pony is one that holds at least 680 litres or 25 cubic feet. Because of its general usefulness, buoyancy characteristics, ease of deployment, and attractive cost compared to smaller tanks, many divers invest in an aluminum 40 (nominal capacity 40 cubic feet / 1200 litres) as the best “emergency” pony bottle.
Two final words on the topic of pony bottles before we move on to gas volume management for more advanced diving. The gas carried in a pony bottle is contingency gas. It should never be factored into the gas volume requirements for a dive. It is there for emergency use only. If the dive plan calls for more gas than can be carried in a regular primary scuba cylinder – an aluminum 80 for example – then the total kit configuration for the dive needs to be reconsidered and calls for an additional primary cylinder or a high-volume primary cylinder such as a steel 15 litre / 120 cubic-foot tank.
A bailout/pony bottle is useless if it does not deliver breathable gas faultlessly. The valve, regulator and SPG must be tested before every dive. Do not take for granted that it is filled and in working order. Analyze and label its contents, check the pressure and wet-breathe the regulator at the start of each dive.
Let’s leave this topic with one last thought. As we were editing this chapter, I read about yet another incident where a diver “ran out of air.” This time a pair of brothers and a friend were hunting crayfish in about 30 metres / 100 feet of water off the coast of New Zealand. Calm conditions at a site familiar to all three divers. Describing the victim, his brother said: He was a competent diver with several years’ experience.

I would suggest an edit… a small change but something that I hope will speak volumes to you. He was USUALLY a competent diver, but not this time. Even several years’ experience cannot compensate for serious oversight.
Plan your dive, dive your plan.

Self-Assessment: an antidote to complacency?

Cleaning out old files and finding a copy of my original dive-plan template – something my buddies and I used for several years when we first started to do deep mix dives – I remember why we scrapped it and drew up a new one: It’s missing an important element.

If memory serves, the error was pointed out by Bret Gilliam. At that time – around 1996/97 – Bret was president of Technical Diving International (TDI) and he was gathering information for student manuals and asking members to contribute things like teaching notes, learning goals, and so on. Among the various bits and pieces I contributed was a spreadsheet template of the dive plan my buddies and I were using, and that I was also teaching students to use.

“It’s good but you’re missing something…” he told me after looking it over for a few minutes. “Something critical.”

I checked it a couple more times and to my eyes the plan looked pretty comprehensive and exhaustive. I told him I could not see what was wrong with it.

“There’s nothing in it about conducting any level of self-assessment before you jump into the water,” he said. “Don’t you think that’s worthy of a line or two?”

There is a well-established maxim that tells anyone who’s listening that complacency kills experienced divers. Checklists and Dive Plans are intended as a good first-line of defence against that sort of complacency. They are intended to counter human nature and swing attention back to things that it’s easy for divers, even very experienced ones, to take for granted and overlook. For instance, I’ve seen divers forget or simply not bother to conduct a positive/negative check after refilling a diluent bottle on their rebreather. A checklist can serve to remind someone with this level of complacency not to be a Muppet.  But, as Gilliam pointed out to me, the most complete, comprehensive and meticulous dive plan cannot prevent things going horribly wrong if the folks executing it aren’t as present-and-correct and as ready as their equipment to do the dive.

Self-assessment is now included in the pre-dive checks for all TDI and PSAI courses, but like the requirement to analyze and mark EVERY bottle of gas, or pre-breathe EVERY regulator – or any of the other listed items on a checklist or dive plan – it is entirely self-policed, and quickly becomes worthless if any one member of a dive team shortcuts that “policing operation.”

The process is simple enough. You ask yourself a couple of easy-to-answer questions and you answer them honestly. Better yet, when the dive leader has completed her self-assessment, she should check with everyone on the team to make sure they all “passed” the self-assessment check.

When we dive – even on those dives that seem like a simple bimble around in shallow water – we must ask ourselves if our plans account for any and all hazards. For the purposes of providing a realistic answer, a hazard in the case of diving is any agent or situation posing a credible level of threat to our life, health and property, those of any team member, or the environment in which we intend to dive.

When we make a self-assessment, that assessed risk includes things that are not visible or readily apparent to our buddies. One is our personal level of comfort.

To check this is the case and that our planned dive is within our comfort-zone, ask: Considering ALL the risks associated with the dive as planned, do I find them acceptable? Does the plan cope with things, events, which have some significant probability of occurrence during that dive? Rottweilers hit the fan and precisely when and how depends on circumstances that may not be predicable. Does the plan make allowance for this and am I comfortable if it does not?

Recreational divers, even those engaged in kick-ass technical dives, are under no contract and are not protected by legislation. Each of us is responsible for our safety and well-being, and – to some extent through enlightened self-interest and the tenets of friendship – with that of our buddies. Honest answers to these questions will help keep us safe and should be asked before every dive; no matter how simple and inconsequential the dive seems.

In addition, there are several other questions we might ask ourselves as part of the “self-assessment” process that should be carried out long before we pull on a drysuit. They concern personal health. We need to ask if we are comfortable with: our personal heart health; are we free from angina, epilepsy, diabetes, asthma, dehydration, and fatigue? Is our cardio and physical fitness up to the stress of the dive as planned? Do we have adequate strength to do the dive as planned? Have we learned and practiced the critical safety skills required on this dive as planned? Are we diving drunk, with a hangover or stoned? Are we physically and mentally ready to do the dive as planned and if something hits a fan while we are down there, are we ready to deal with it appropriately?

It may seem a little odd, but self-assessment should also ask: Do we believe in our buddy’s abilities and do we feel they have the skills and experience required to do the dive as planned? Are we being over-confident expecting ourselves and each member of the team to do the dive as planned? Does that hold up if we become separated? Do I feel the same should it become necessary to rescue a buddy on this dive… can I rescue them and can they rescue me?

Self-assessment does not always return a positive answer. But self-assessment is a positive habit to fall into and it needs to become part of the pre-dive preparations for EVERY dive… especially any dive that requires the use of decompression gases to manage a decompression obligation, or that takes place in a hard overhead environment.

The Rules Apply to All of Us

If you are a technical diver — a cave diver, a trimix diver, a rebreather diver, something of that sort – you have read someplace that complacency kills experienced divers. Fact is, you may have read it several times and heard it said repeatedly because that phrase is contained in most if not all technical diving textbooks. It is so commonly bandied about that for some of us, it may have become a little trite… a cliché… something to become complacent about.

Time to smarten up.

Recently, there was yet another senseless death, which might serve to illustrate the point. This one happened at Ginnie Springs in north Florida.

A young guy named Carlos Fonseca had an oxygen toxicity episode a couple of hundred metres inside the cave and died. He was breathing from a stage bottle clearly marked oxygen and later analysed to be just about pure O2. According to statements from the folks diving with him, Carlos thought he was breathing air.

Before the dive started, he was questioned about the bottle, challenged about analysing it, but insisted that he had filled it with air, even though it was labeled for dedicated oxygen service. Now he is dead.

This incident is sad and terribly tragic… a family without a dad/husband/son/brother et al… But unfortunately it is not surprising that a certified cave and trimix diver died doing a simple, run of the mill dive that was WELL within the scope of his training and experience. As slight as his experience may have been, and as rapidly as he had progressed from open-water diver to cave diver, the dive was a simple one for which he had adequate training.

Diving is an activity that requires some restraint because it is so easy to push beyond one’s capabilities… as Steve Berman once said — and I paraphrase — any twerp can get to the back of a cave. But not everyone can manage the journey back out.

I did not know Carlos… never even met him… but I do know the fella who taught him to cave dive and a couple of buddies had dived with him during the past couple of years. He had progressed from open-water punter to trimix and cave in a couple of years. He had the money, time and desire to do so.

The over-arching assessment from the people I know who knew Carlos was that he was very confident… perhaps to the point of arrogance… but so what. He was certainly enthusiastic. He had completed 100 cave dives in a couple of years, and when you live a 16-20 hour drive from the caves, 100 dives is enthusiasm in bold letters. But, in truth, he really had not been diving long, and he certainly did not have vast experience regardless of his many postings on onLine forums and Facebook, and even though he had ticked off several “big” dives in his logbook. However, I do not believe any of that had anything to do with him being dead right now.

Experience whispers strange things in our ear. I have lost many, many friends to diving, and have seen many people who I did not know personally… like Carlos Fonseca… die in the water. Part of the work I choose to do involves picking through the debris folks like Carlos leave behind. The task is to identify what went wrong and make sure others understand the circumstances surrounding the incident, the events that triggered an incorrect reaction perhaps, so that nobody makes the same bloody error. Sometimes this is difficult, but not in this case. There is no doubt about what happened; no question what triggered the victim’s death or whose actions contributed to that death. Of course, the resulting analysis may be difficult for some to accept.

A buddy of mine is a lawyer who specializes in cases where some poor bastard has died, and he tells me his staff have a kind of open pool going to see how long it is before a friend or relative says, writes or posts on the internet something along the lines: “He was the best diver in the world… I simply do not understand how a thing like this could happen…”

Someone always says that, even when the diver is a total novice… just like that kid who died in California a couple of years back trying to do an air dive to 80 metres. He was a divemaster… maybe, I forget. Anyhow, he had ZERO training to do that sort of dive but the boy’s father insisted his son was a “professional” and would not accept evidence to the contrary… or that his son had probably been lulled into complacency and hubris by his slightly more experienced and certainly older dive buddies.

In the case of Carlos, we know what went wrong and we have evidence that the victim ignored warnings from his fellow divers. He certainly ignored best practice. He is not the first diver to make such a rookie mistake, and the fact that a few years ago he knew nothing at all about diving is truly irrelevant. He DID know what SHOULD have been done. He had sat through training and certainly had correctly answered exam questions on gas management. HE CHOSE TO IGNORE WHAT HE KNEW. This is not because of lack of experience or because he progressed rapidly. He simply ignored what he knew to be the right thing to do… that’s a function of character, poor judgement, pressure or stress: take your pick.

In the final assessment, Carlos Fonseca believed the rules did not apply to him. He certainly knew that the established practice is to ANALYSE and LABEL every cylinder that goes into the water.

Is there something to learn from this incident? Of course there is. It’s the title of this piece. But there is also something else I would like to remind you of just in case someone reading this has ANY doubt. YOUR BUDDY IS CARRYING YOUR CONTINGENCY GAS… IF YOU DO NOT KNOW WHAT IT IS (first-hand, having checked for yourself) THEN YOU SHOULD. YOU may need to breathe it at some point. There can be NO credible argument against this, in my opinion.

The Best Rescue Divers Don’t Have to Rescue

It may sound strange but it’s generally accepted that the best, most successful rescue divers don’t have to actually rescue anyone because they are able to recognize signs of impending panic and are savvy enough to intervene before true panic happens.

Of course, the question most aspiring rescue divers ask at this point goes something like: “Is that a learned skill, and if so, is it difficult to learn?”

The short answer is: yes it is, and no it isn’t!

When we imagine a rescue diver in action, what flashes before our eyes – initially at least – is an image of a neoprene-clad hero(ine) pulling an unconscious diver from the raging surf… Think GQ cover meets Surfer Magazine and you’re halfway there. Then after a few nanoseconds, the real image kicks in and it’s not so pretty; not as organized; and certainly not as heroic. The truth is that a full-blown rescue, as welcome as it may be in a disastrous situation, is simply something we should strive to avoid at all costs. In essence, a good rescue is one that may consists of a quiet word before the dive and either a change in the dive plan or a retreat to the nearest café for a coffee, a Danish pastry and a chat about tomorrow’s dive rather than today’s.

One of the pre-dive skills required in every technical diving program is something labelled stress assessment. This step in the pre-dive ritual is a vital “rescue” technique, and it applies to both self-assessment as well as buddy or team assessment.

Given that you and your buddy or buddies are certified, equipped and have the experience to enjoy your planned dive without undue risk, the day-by-day stock questions you should ask yourself are: Am I up for this dive? Do I feel good about the dive conditions today? Do I feel ready to do this dive? Am I comfortable with the things that need to be done to make sure this dive is fun? And finally, how does my buddy (or buddies) feel about the dive?

This step alone – coupled with honest answers and a real understanding that there is no shame in calling a dive at any time… even before you pull on your gear – goes a long way toward making you a “successful” rescue diver.

Speaking with divers following an aborted dive — a dive where things went absolutely pear-shaped — a sobering but not surprising statistic is the large percentage of them who say: “I just knew something was going to go wrong,” or “I had a funny feeling about the dive before we suited up.”

If a rescue diver has one simple but truly important task to do at the dock, on the beach, at the dive site before the actual in-water part of the dive starts, it’s to conduct a quick survey of every diver – including herself – to check if everyone really is happy with the dive plan and feels no pressure to do the dive.

During the dive itself, even without the use of diver to diver voice communications, there are ways to keep checking that everyone is happy. What are they? Let’s review the opening statement that was used to kick this article off… “Recognize signs of impending panic, and are savvy enough to intervene before it happens.”

This form of clairvoyance – being able to tell when something is about to fall off the rails and do something about it BEFORE it happens – is not telepathy or some other psychic power, but a perfectly attainable skill called Situational Awareness, and a good rescue diver needs it.

In the most general terms, situational awareness is perhaps the most under-rated, unsung components of safe and successful diving operations.

In advanced diving discussions, we have adopted the term Situational Awareness (SA) as a sort of catch-all phrase to describe what we mean when we say: “keenly aware”; and probably for good reasons. SA has been a core concept in high-stress operating environments, such as the military and aviation, for many years.

In these milieu, SA skills support the ability of individuals to handle complex and rapidly changing situations in which informed decisions – directly relating to personal and team well-being – need to be made under tight time constraints. In these high-stress settings, lack of SA is one of the primary factors in accidents attributed to Human Error.

For the purposes of rescue divers, SA is best described as being aware of what is happening around you and your team, and understanding how the flow of events, and the actions of team members will impact your dive’s goals and objectives; both now and in the near future.

It also encompasses the skill of selecting which bits of information are relevant and which are not and can be discarded.

Put briefly, SA is the chess-player’s skill but applied in an environment where checkmate can result in real physical harm, and not just a wooden game-piece being knocked sideways.

One key sign of a buddy’s comfort level while underwater is his or her respiration rate (at least on open circuit gear). A nice relaxed breathing rhythm generally means a nice relaxed diver. Faster breath cycles may be a sign of tension, carbon dioxide build-up, overwork, and are often the first outward sign that forewarns of events that can domino into bedlam if left unattended.

I have a good idea of my normal breathing rate during a moderate dive – it’s around eight per minute and therefore somewhere south of the adult resting average of 12 to 16 breaths per minute. I self-monitor during a dive, but I also pay attention to the bubble “signatures” of the divers around me, trying to pay particular attention to changes in the frequency of each diver’s exhalation. It’s certainly not a definitive marker of approaching problems, but a rapid increase in breathing is something a good rescue diver might want to pay attention to.

If your buddy starts to work hard and breath more heavily than usual, get their attention, slow them down, give them some reassurance — such as an OK sign and a squeeze on the arm — will show them that you are watching out for them. Something as simple as getting a diver to pause and wait for a few beats before carrying on can easily avert an unpleasant episode further along.

If you dive with the same crew on a pretty regular basis, you also learn other more subtle signs and body language that will indicate that they are less than comfortable.

As a rescue diver, it is always in YOUR best interest to pay attention to these little markers during a dive. Sure you may be capable of executing a perfect tired diver tow and safe ascent with a semi-conscious buddy, but why take the chance when that whole scenario can be avoided by stepping in a few minutes early?

A slightly different version of this article was first published in Technical Diving International’s eNewsletter in June 2013.

What it takes to lead a technical diving team: A suggested plan for staying real and managing risk

One of the most interesting dynamics of technical diving… both during its planning and execution… revolves around the issue of leadership. It’s not simply a question of who leads and who follows but a much more complex balancing act between responsibilities, experience, team composition and dive goals. And since technical diving is recognized as a high-risk, team-oriented activity, coming up with the correct answers can mean the difference between a great dive and a bad experience.

I guess the most important first step is to understand what we mean by leadership and the factors that inform that definition.

We should start by pointing out that one of the fundamental guidelines recommended is: “The weakest diver leads the dive.”

Now weakest in this context is not an assessment of physical strength or mental fortitude – although these may be factors in some cases. More usually a diver may be “weak” because he or she has less experience with the particular sort of dive being planned and how best to achieve the dive’s specific goals; or they may start the dive with another more subtle disadvantage. On some ocean dives, weakest may be the diver most prone to seasickness and who has taken meds to help deal with that particular stress. It may also be the diver who among his or her peers on the particular day in question wakes up the least rested or most stressed… as in “I’ll lead the dive today because I had a restless night.”

Whatever the actual reason for “weakness” the logic behind this guideline is that it helps eliminate “trust me dives.” In cases where the least experienced diver is the leader, it also offers the best opportunity for that diver to expand his or her comfort zone. Let’s take the example of a cave dive with a three-person team. For this example, let’s say that two of the team have explored the cave on several occasions but for one, this is her first time in. All three may be experienced cave divers, but one is certainly at a slight disadvantage. By having her LEAD the dive, two things are assured. Firstly, she will not be lead into a situation which she finds uncomfortable. Her level of comfort on the dive will most likely be increased since it will go at her pace, and with two companions to “guide” her when the time comes to make a decision – for example “is this the right side-passage to take…” – her comfort zone may be expanded but not breached.

The result will most likely be a much more enjoyable dive for everyone involved since stress levels can be better managed.

This example of leadership during the actual execution of a cave dive may not relate directly to the type of diving you do, but the logic is transferable to all varieties of technical or complex advanced diving whether in a hard overhead environment or not.

It also introduces us to part of the complexity that surrounds the whole question of Leadership in Technical diving, and its definition relative to the importance of coaching and mentorship in the process.

Let’s recap and redefine a little. The weakest diver leads during the EXECUTION of a dive, but this diver would most likely take a backseat role during the actual PLANNING of that same dive.

If we go back to our example, let’s travel by time-machine to a day or two before the execution of the dive to the time our three dive buddies sat down together to plan the dive. We know that all three are experienced cave dives and during their initial assessment of the dive’s parameters they agreed that each had the appropriate training, familiarity with the required equipment, and general experience in the type of environment. What was apparent was that one needed a detailed briefing on the specifics on the dive since she had never been to the site before. This is where the dynamics that influence leadership in technical diving comes into play.

In old-school terms, leadership might be interpreted as the behavior of a tartar or martinet. A person who demands strict adherence to his or her rules and any deviation from those rules will result in some sort of punitive reaction: verbal or otherwise. I am reasonably sure that many of you have first-hand experience of this form of bullying and “management” by intimidation. There is no place for this style of leadership in technical diving… or anywhere else actually. It may have worked to send hapless souls over the trenches during WWI but is about as useful in diving as ashtrays on a motorcycle. There is simply no room for this attitude anywhere close to technical divers planning their dive.

The leader during this stage needs to be empathetic, supportive and their role is more akin to a coach or mentor: someone who encourages others to contribute ideas and suggestions. A real leader shares knowledge, has real information, suggests better alternatives when asked, and gets satisfaction from helping others grow. Essentially, a good leader produces good leaders.
In the example of the planning for the cave dive, the leader might respond to questions about distances and times with something like: “what do you feel comfortable doing?” rather than pushing his or her agenda. In fact, an important part of the mentoring process is to promote the goals of others even when it makes their own subordinate.

For most of our dives, up-front considerations of leadership are a little over-the-top. The vast majority of dives – even technical ones – follow a pattern that is established within the team and roles and responsibilities are simple, understood and virtually unspoken. Often on this type of dive, leadership amounts to little more than: “Hey Jill, how about you run the reel today?” But when game-day brings those special dives… the apex dives for your team… give special consideration to the dynamics of team leadership. Oh, and remember that changing circumstances at depth, may alter who is “weakest” and may require change of “leadership!” But of course, that’s something best learned under the mentorship and coaching of an experienced technical instructor!

A slightly different version of this article appeared in TDI’s eNewsletter in May 2013

How much of a conservative are you?

When it comes to storage and use of the ‘kitty litter’ used in rebreathers to scrub carbon dioxide from the breathing gas, I had until very recently thought of myself as ultra conservative. Turns out this was not necessarily the case.

I was careful with the storage part and careful when packing or loading the scrubber canister of any unit I dived with, but it turns out I misunderstood the actual working life of the absorbent once it was partially used.

Now I should make it clear that the only absorbent I have much experience with is Sofnolime® 797. This is a product made by Molecular Products in the UK and – in my circles at least – is the gold standard for use in closed-circuit rebreather diving. For the record, I use what’s called the non-indicating variety, which means it does not change color when suffused with Carbon Dioxide.

Sofnalime® itself looks a little like a white version of the material used in a cat box (hence its street name), and is actually a triangular cross-sectioned extruded pellet made in part from calcium hydroxide with a little sodium hydroxide mixed in, and is between 1.0 mm and 2.5 mm in size. It is alkaline (a pH between 12-14), slightly water soluble, and non-corrosive – but the dust will irritate the eyes and perhaps the skin, and inhaling it is a definite no-no.

In simplest terms possible, the chemical reaction that takes place inside a rebreather’s scrubber removes carbon dioxide and produces heat and water, and turns the soda lime into chalk (calcium carbonate). Also, for the record, in addition to proper storage and handling of unused scrubber material, used soda lime should be disposed of responsibly. Whenever possible, I take it home and then spread spent scrubber material on the garden where horticultural lime might be indicated, and put the rest in our horseshoe pit.
Ok, now with that clear, let’s focus on my misunderstanding.

Rebreather manufacturers tend to rate the working life of the scrubber material in their units based on the size of the scrubber canister. Literally on the amount of kitty litter their machine holds. In a perfect world, we might ask for a slightly more scientific method to gauge this, but referring to an X-hour scrubber is the norm. Certainly, this is what I was taught… but it is not what I teach; and here’s why.

After speaking with one of the chemists at Molecular, I learned that the method commonly used to indicate the effective life of scrubber material (i.e. Sofnalime®) is incorrect. While a freshly charged scrubber may have X or Y or N hours of potential effectiveness ahead of it, that number of hours is an estimate based on continuous use.

Let’s say for example that a rebreather manufacturer designates its scrubber duration as four hours. This means up to four hours on one dive and NOT two two-hour dives back-to-back on the same scrubber. This, according to Molecular’s chemist, would be “pushing it.” There are several other considerations that should be taken into account when estimating how much ‘life’ is left in one’s scrubber but on straight, no frills, moderate depth dives (such as shallow cave dives in North Florida which would normally be to depths less than 30 metres/100 feet) after one two-hour dive on a ‘four-hour scrubber’ perhaps only an hour and a half is left, and NOT two more hours. After a couple of one-hour dives, a third dive to 45 minutes or so, will all but exhaust the remaining Sofalime® so that in actual use, the effective life – and safest interpretation – of a four-hour scrubber would be less than three hours.

Now, it should be said that estimates of scrubber duration from manufacturers tend to be conservative and are usually based on the worst type of conditions; however, I found it interesting that the guy who oversees the manufacture and testing of the active component in the little chemistry set I lug around on my back to go diving, is more conservative yet.

And I for one will follow his example from here on in.