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Choose Your Students Well, Less Teacher’s Hell Will Slowly Go By

We’ve all heard the mantra, “Choose your instructor carefully!” Wise words, right? What about choosing your students? Here Stratis Kas, tech diving instructor and author of the book “Close Calls,” recounts his rather sharp learning curve in choosing suitable students! NOT! They did what?!?



By Stratis Kas
Header image and photos courtesy of Stratis Kas unless noted.

Choose your instructor carefully! This may be the most popular mantra in diving education. Heck, I have not only said it many times, I even wrote about it in the August 2020 issue of InDepth: Technical Diving Myths vs. Reality. As much as this remains true, it’s also incomplete. Diving education is not just knowledge. When done well, it’s mostly mentorship—…a proper relationship between student and instructor that starts during the course. As with most relationships, there are great highs as well as disappointing lows. Also, as in life, responsibility for the success or the failure is borne by both sides.

In an ideal world, all dive training should result in responsible and ever-evolving divers who themselves become mentors for the next generation. This, of course, is more than often not the case. As with all instructors, I have been both a student as well as an instructor many times. We all started as divers and then evolved throughout our training until finally some of us chose to keep on learning by electing to teach. 

Unfortunately, in the ever-increasing commercialized reality that diving is becoming, it’s practically unheard of for an instructor to fail the student before the course has begun. 

There are many influencing factors involved in the decision to not reject the unqualified student. One of those reasons is about business. A  potential client who is turned away not only means an immediate, measurable loss of income, but even more importantly, can—and will—affect the instructor’s reputation in the market, as no rejected student will likely be  honest about the reason the course did not happen. All the blame will fall on the instructor, who “for no reason” chose to not proceed with the training, even  if, from the instructor’s perspective, that may have been the most responsible and principled thing to do. And if the student quits diving in reaction to the rejection, that rejection could have saved their life. 

 Some instructors might be  personally challenged to succeed where others did not, or perhaps chose not to try. In these cases, the outcome, should it be positive, will be because the instructor expended a great deal of effort in order to allow the student to succeed and to achieve the best results. It may be driven by ego, but the end is met.

As training is still very unregulated, when it comes to skills and knowledge on all levels, instructors who encounter students who do not meet the minimum requirements to enroll in their courses are faced with a dilemma. What is the correct thing to do? Do instructors, as well as training agencies, need to become more exacting in their acceptance of a student? Do check dives need to become a standard? 

I require all new students to do a check dive to demonstrate that  all the basic skills and knowledge of their level are confirmed in order to focus on the new skills and not on what is supposedly already known. A classic example is when divers expect to learn position control during their cave course. This is unfair for both student and instructor, as the students do not utilize all the water time to progress in their specific course knowledge, and the instructor is now required to hybridize a very straightforward training plan, naturally with fewer chances of success.

I am lucky not to have to depend exclusively on diving training for my financial survival. But I also hope that even if that was my only source of income,  I would follow the same protocols—making sure that my future students were ready for what they wanted to do next. Not just physically (very important) but also mentally. So what do I do when I am confronted with a very weak candidate? 

Nowadays, I just say “No,” and I follow up with a very thorough explanation of why I said that. But, I haven’t always made this wise choice.

I hoped to enlighten, or at least entertain you, with a small selection of  challenging situations that came my way earlier in my career. Some good, some bad and some, straight down ugly. Enjoy.

An unabashed cert card collector

We’ve all had them—the people posing as students saying they want to learn how to dive when what they really want is the card. The number of certification cards in their wallets matters much more than actually learning to dive, and what someone will do for a plastic card boggles the mind. Even so, rarely do they admit up front what they are after, but a few years back I received a phone call from a certification card collector who openly admitted that was all he cared about. Even though I tried to persuade him to look elsewhere for his training, he wanted me. In the weeks that followed, I started liking the guy, mostly because of his brutal honesty. So, I decided to give it a try. This was a non-tech diver who wanted to become Full Cave certified. As this is not completely uncommon, I was open to hearing more about it. 

And then the madness began! “John”  made it clear from the start. He did not care about theory or exams. On the other hand, I am a stickler for theory, and at the time I was teaching from my own cave diving manual for CMAS—a manual John never opened. When I explained that he would need to take the examin order for him to pass, he remained uninterested. Every dayJohn proved to me that he was not even close to being ready for the course. While I was used to students who tried to hide their weaknesses, John was open and proud about his. 

Photo by  Cave Training Mexico

I’ll admit it: I was hooked. When we arranged to go through his equipment needs for the check dive, he  was expecting to use his brand new drysuit without proper training. I explained to him that this was not possible, and he then planned to dive the 11ºC/52ºF cave with his wetsuit. What this man was apparently willing to do for a plastic card amazed me. 

Next, when we discussed the need to meet  at a local swim pool to do the check dive, John informed me that he needed for the session to not exceed  45 minutes because he couldn’t go longer than that without a cigarette break.He also said he planned to  urinate in the public pool whenever he needed to rather than exit the pool and use the restroom. I was working on how I could handle the untenable situation when a drowning accident resulted in the cessation of access to all public pools, saving me and tightening John’s timeframe. He then decided to train with a different instructor, much to my relief, and some time later I learned that he had gotten certified to teach cavern courses with his full cave certification card.

What should I have done differently? I should never let myself agree to ‘teach’ this arrogant man. I was fascinated with his obvious disregard for protocol, and somehow must have let myself believe I could do what no other instructor could–help him to see the importance of proper training. Never again.  

Students with personality conflicts

As a brand new instructor, I was inclined to “over deliver,” and perhaps this influenced my decision to teach three divers at once. Knowing what I know today, I would advise a new instructor to take on one or two students, but certainly not three simultaneously. Only experience can help an instructor read signs that precede potentially dangerous situations, and it’s very difficult to keep an eye on three students simultaneously.

 My three students—all men—were uncomfortable with one another from the outset. Tension was palpable in all our classroom theory sessions, complicated by conflict in the relationship dynamic of a recent breakup of two of the guys with the addition of a potentially new  friendship forming. There was lots of competition, and the mood was surly.

 A check dive was not required—my second mistake—since all of them were already tech divers, having been certified by a well-known instructor. One of the divers, “Bill,” was the better diver, the only one who seemed to be suitable for the course, and the only one able to remain still in the water and pass all the open water skills and the cavern dive. His success escalated the rivalry between the other two, as they tried to best one another to be as good as Bill.

 During our first full cave dive, we had to pass through a restriction at the cave’s entrance. To my surprise, Bill refused to do so. We consequently exited the cave and Bill ungeared.

 I then dove with the other two divers, and a few minutes into the cave, an emergency was simulated, and one of the started self-rescue procedures, ignoring the protocols of team diving. The dive was called, and at debriefing, I terminated the course.

Photo by Yannig Charles.

 At a later date, one of the two divers successfully finished his cave training with me, but Bill and his new friend chose not to learn basic skills that would allow them to be ready for a proper cave course. They were both later certified as full cave explorer level by a different instructor. 

What should I have done differently? Certainly I should not have jumped into a three-student course on my first experience as a new instructor. Also, I needed to  be more aware of team harmony—and disharmony—and to relay to my students exactly how important it was.  If two divers are at odds with one another, instructors have every right to question their willingness to save one another in a cave. 

Note: Nowadays, I use this restriction to check the ability of all new full cave divers to deal with the actual environment they are certified for. If that restriction is too much, full cave diving is too much. 

The uptight, overstressed candidate

This is a case of a student’s overall demeanor, possibly practiced, belying his internal signals of distress.

“Joe” was an educated man in his early forties. He was successful in his work that involved not only following protocols, but also thinking outside the box. He was an ideal candidate, or so I thought. He was excited and focused and a pleasure to teach. Our open water sessions were successful, as he performed all simulated skills with ease. I noticed but ignored that as he was performing skills well, there was tension in his hands. Even as he was simply making a tie off, his hands shook. Because he was such a high performer, I didn’t examine it more closely. 

Our first cavern dive was reachable only by boat. We were anchored in front of the sea cavern, with the seafloor 5-7 m/16-23 ft  below us. The cavern was  beautiful and perfectly suited for a first overhead experience. This cavern was nearly all open on top, with a massive central air space. To a student, it could feel like cave diving; I knew better.

Joe geared up and chose  to jump in before he donned his fins, claiming that was simply easier for him. However, as soon as he entered the water, his overinflated wing’s valve  popped, and he lost all his buoyancy. He was properly weighted, and had he been wearing fins, he would have had no trouble remaining at the surface, even with a failing wing. He also had two fully functioning regulators, one in his mouth, and he could see the bottom a few meters below him. His fins were in his hands, but none of that computed with him, and he panicked. He began to fight the descent, and he screamed. Three people immediately jumped in to save him, and once back on the surface, he needed 10-12 minutes to recover from his panic attack. 

What should I have done differently? I needed to watch more closely for subtle signs of stress, because “Joe’s” slight signals that he was frightened and distressed, even though they belied his general demeanor, were real, and they were red flags that I missed. 

The privileged professional 

“We never stop learning”. If only that was true. 

Some of my worst students have been diving professionals who want to be certified at technical and cave levels in order to teach these disciplines at a lower level. 

Two separate instructors, “Adam” and “Ned,”  were part of a course that also involved a student who was not a diving professional, “Roger,” and that combination proved disastrous. Once our dates were firmed up, I prepared the proposed schedule and sent it to each student. It was fully detailed, including breaks, transfer times, and meals. In respect of my training organization, the schedule fully followed the standards, even if it was intense. It was a full cave course. It was going to be intense. 

In addition to the email, I organized a group video call for the purpose of allowing the students to introduce themselves to one another and begin team building. 

It was a cold winter day when we all met for the first time in the classroom. I had the chance to informally discuss diving with the two professionals before the other diver arrived. Then, as soon as the class began, I  felt that we were conducting a co-teaching course with Adam. Not only from his interference in my theory, but also his constant interjecting questions that were more commentary than actual questions, as well as in his body posture in relation to the other students. 

I took Adam to the side and explained to him why this was not only okay for me and the other students but essentially also for him, since, by taking on that co-teaching role, he was not absorbing information the proper way. Adam did not like that, but he seemed to accept it, and we moved on. 

Not more than one hour more passed, and on the theory break, Ned informed me that he, as “he already had the skills,” he would not be able to do the swimming pool skill sessions in the late afternoons. His reason was that he had to go back to his family and take care of the kids. 

As readers probably know, advanced cave diving courses are not a 9-5 thing. They cannot be. Their success is based on full immersion of the entire unit (students/instructor/assistants) for the length of the course. Dive courses are meant to keep divers alive—and therefore to keep them with their families. Ned was shocked to hear that his request was not going to be approved, because he was sure he would  have the understanding of a fellow instructor. Ned decided to stop the course, and he asked me for a refund, then a partial refund, and then finally threatened to report me to my training organization for not catering to his specific needs. As a reminder, the full schedule with exact times and explanations had been presented before the course started, making his threat baseless. 

This is important for all instructors out there: do not make special exceptions that modify your course and what you need to make it fair, equitable, and effective, to satisfy the wants of your students. That does not mean that an instructor should not try to accommodate requests, as long as they are reasonable and  do not compromise either the scope and integrity of the course or the other student’s needs. 

The next few days went on quite okay. Adam and Roger (our nonprofessional student) got along very well, although Adam seemed distracted.  After the fact, I concluded that he had continued to resent me and spent a lot of time in his mind imagining how he would be conducting the course.

On our second to last dive, in an objectively easy cave regarding navigation, Adam was connecting the open water to the cave’s main line. I was following side-by-side with Roger, checking Adam’s placements and tie-offs. At the main line connection, Adam connected his primary reel onto the main line and directed the reel’s double ender toward the inside of the cave. In cave diving training, we consider all bolt-snaps and double enders connected to the main line as directional markers. Therefore Adam made a critical mistake. A potentially deadly one. Even worse, Roger, who had grown not only to like but also to respect Adam as a diver, was looking at the reel pointing the wrong way, and wondering why it was not done the way he learned. Roger did not consider Adam a fellow student but a mentor, or even a co-instructor. Therefore, to Roger, Adam could not have made such a mistake, and Roger was unsure how to fix it in the field. 

Roger looked at me and pointed at the reel. I wrote on my wet-notes,  “what do you think?” Roger froze. A minute passed, and I called the dive. On our way out, the primary reel got cut, and Adam executed a perfect repair. Out of the water I asked them both if they knew why the dive was called. Roger stood silent and Adam, in a good mood because of the great line repair he had made, asked if any of us had a serious failure that justified the dive ending. 

Back in the classroom, I asked Adam to repeat the same procedure of connection to the main line, which he did correctly this time. I requested another open water simulation skill day to refresh and make sure potentially life-ending mistakes would be avoided. Roger was still frozen, but Adam, when confronted with the mistake, denied that he made a mistake on the connection (thank God for my GoPro), then he tried to explain why “it was not such an important mistake” being so close to the exit, until he finally left the class in a fury. The next day, Adam did not come back. 

Many theoretical elements or practical skills can—and will—be learned by making mistakes and getting better each course day, but there are two categories in which I will not tolerate even a single mistake during the last phase of training. These are navigation and gas management. The reason is simple. They are the main issues that will kill you in a cave. And also they are simple enough for anyone NOT to make a mistake once they are learned. If a student makes a mistake regarding navigation, they have endangered lives.

What should I have done differently? I think I should have figured out what  both of the professionals’ true motives were for taking the course. According to skill alone, they were probably suitable for cave training, but I believe they were status seekers, both of whom with attitudes of superiority. In Adam’s case, he was unable to be called out on a mistake, which made his ego such that he was not a good candidate. Roger is now certified and enjoys cave diving recreationally. 

The student who could not count to save his life—literally

This will show my age, but there is a critical issue that recurs in many if not most young people today when it comes to general education and knowledge. Maybe it’s dependency on electronics that has substituted for using one’s brain, or (sadly) perhaps today’s teaching does not demand, nor even encourage, basic skills such as simple math. 

It was a very hot summer night when I met Jonas. Jonas immediately showed a great sense of humor and comfort with himself. as the days passed, we became friends. Heasked me if I could teach him some tech theory in the afternoons on his breaks, and I accepted. Jonas had attended a few tech courses as an intern but got “charmed” by my methodology and approach when we were comparing plans. He wanted to feel “in control” instead of following blindly what a program would tell him to do. I liked Jonas. 

Everyone has their strengths and weaknesses, and I am good at math. Relatively complex math thinking is easy to me— it feels natural. In my first years of teaching math requiring courses (gas management and decompression) I often saw students having a hard time following my logic. Not expecting that we are all comfortable with my personal way to interpret and calculate the above subjects, I decided to focus on helping them realize that once the logical thinking is there, the calculations were easy. And even more importantly, mistakes stood out because of this same logical thinking (example: if a double cylinder “gives” 400 minutes of gas consumption at 30 meter’s depth, something is almost certainly wrong).

Jonas showed from the start that math was difficult for him. Not an issue, I thought, as many people are not. Surely the basics would be there. At the end of our second session Jonas had to calculate 80/4 (=20). Surely this should not be a problem. But Jonas froze, and after half a minute or so, went for his smartphone calculator app. I immediately stopped him. “Come on man, how much is eight divided by four,instead? Let’s start there.” Nothing. 

I was teaching decompression and gas management to someone who could not calculate simple equations, which would have caused serious issues for him, but one stood out more than the others. Since Jonas avoided all math related experiences, when he was asked to calculate gas for an emergency cave return scenario (he was already cave certified), he simply could not. During the next few days, we were supposed to discuss “in water gas recalculation,” and I had a dilemma that I could not take lightly. Jonas would not be able to learn any of this the proper way. At least not at what I consider minimum standards to justify the risk of technical diving and reduce it to “acceptable”. 

I had  to explain to Jonas that I could not certify him after all. 

What should I have done differently? At the time of the event, nothing. Nowadays, I take much more seriously the assessment of pre-existing conditions when it comes to teaching these courses. I not only do a water check dive, but I also explain the importance of this logical thinking and basic (at least) grasp of math for diving training. 

The student who certified himself

I believe (and hope) that this situation is so rare that it has to be an individual incident.  Since it was not a proper paid course, and I was simply “mentoring” the individual while working together in the same facility, makes it so much more serious. 

“Gus” was a talented young man who had been an athlete all his life and was good at anything sports related. As a consequence, he was very good in the water. His skills were top notch, and all signs pointed to him having (as per his own wishes) a very successful career as a diver. Gus was not yet 20 years old when the issue occurred. 

We met in a hybrid tech/rec facility where, at that time of the year, mostly recreational divers were clients. For Gus, it was a boring time. Instead of visiting caves and doing deep tech dives, he had to guide in shallow reef dives. Since he was spending a lot of time with me, Gus started to feel comfortable with me, and he asked me questions like if I thought he should be certified at levels higher than he was, based on his skills alone. 

The truth was that he had those skills, but there was no time for the instructor to spend training him because it was the busy season for the dive center. This frustrated Gus every day. Seeing that, and feeling sorry for him, I proposed to the diving center that—if they were okay with it—I would train  Gus on our free days. My main motivations were mixed between it being a good thing to do and my own boredom. Also, I believed Gus had what it took to ace the courses smoothly and easily.

What happened next is a cautionary tale. As I entered the system to register Gus for the courses he wanted (I was planning to surprise him) they were not available. This could happen only two ways. Either I was not certified to teach them (which was not so) or he was already certified at those levels, which made no sense, as he kept saying how much he deserved to be certified. Naively blaming the system’s error, I let the issue go for the day. But, then the next day, I received an email from my training organization that congratulated me for certifying Gus at the course A and B. My mind was not able to process the information. What was happening? 

When I confronted him, Gus initially denied everything. As I pressed him more to “confess,” he finally did, explaining that he deserved the certifications and that he had used my name as an instructor in the system which he had access to, to certify himself.

To this day, this is my most shocking memory as an instructor. 

What should I have done differently? Nothing, except learn from it. Take nothing for granted, and never underestimate the deviousness of a highly motivated and unprincipled person to get what they want. My experience with Gus was an eye-opener and made me look at the world a little differently.

The student who gives up (all the time)

Being humble is nice. And it allows room, by removing the ego for new information and knowledge. But there is a limit to everything. And constantly putting yourself down (looking for a compliment maybe?) will not make you a better diver. Nor will it make you more likable. 

“Martin” was one of those divers who started diving late in life, and he wanted to do it well—perhaps even perfectly. Which was why we got along as soon as we met. I failed to identify Martin’s problem because he seemed one one hand optimistic, while on the other hand, he kept using phrases such as,  “I will never be as good as you,” which I should have seen as red flags. I ignored them, as many students start out with that attitude, but lose those envious statements as soon as they start to feel good about themselves.

As usual, we went in the water with another two students to do our check dive prior to the course. Martin was unlucky in that the other two students were probably the best I ever had the privilege to teach. Which meant that the difference was obvious. I think that, as a minority, Martin was sensitive about being seen as incompetent/inadequate, while the other students represented the norm. Our check dive included a series of skills performed on a stage made with a guideline in order to verify the student’s ability to stay still and control their position in the water. Having control of where you are in the water is an essential and often overlooked skill that, in my opinion, is absolutely mandatory for all overhead and technical courses. As these courses add new skills, the divers should never enter into such courses hoping to learn or improve these basic skills. 

The two other students performed their skill almost proficiently from the first try, and when it was Martin’s turn, he could not do much. He was not ready for the course in reality. His love of diving was greater than his skills. Which is okay, especially for a person with a good attitude such as his. All I needed was to cater the course more specifically to Martin and separate it from the other two, obviously much more advanced, divers. This happens. I was not worried. 

As I approached him, Martin stared at me, frozen. No matter what I tried to explain to him, or adjust things for him, he simply started into nothingness and floated like a dead fish. Initially I  hoped that he was trying to achieve a still position in the water. I soon realized that it was not the case. 

When the dive was over, as I was trying to explain our situation and how I wanted to deal with it, Martin began speaking very disparagingly  about himself and saying that he now accepted that he would never be what he hoped to be, and that all the people who told him in the past that he was not good enough were right. I tried to explain that, considering that none of these people were serious divers themselves, and also were not in Martin’s life anymore, he needed to come out of that dangerous self-pity loop that he was in. 

Sadly, Martin kept quitting every chance he had. From simply freezing underwater, using cold as an excuse to end the dive, to even leaving the water on his own. It took more than a month of back and forth, and a lot of buddy bonding drinking nights, to manage to get Martin to trust me that I would not be another one who would tell him that he was not worth it as a diver.

What should I have done differently? Not sure, as still today I strongly feel that there was no better way (for Martin) to proceed through the course. Not sure I am up for another one like this, though. For an instructor, the satisfaction of the student is very important. It’s what keeps me going. My small consolation is that at least now he can dive properly.

And then, even if so rarely, there are the ones I want to add extra diving days to their course. The ones that I feel, “I should have filmed this course and used it as personal promotion.” When everything is so smooth that I forget all the bad ones and remember why I love teaching so much. 

You know who you are, and I thank you personally, once more.

Additional Resources:

InDepth: Technical Diving Myths vs. Reality Greek cave instructor and filmmaker Stratis Kas explores some of the unstated myths about tech diving and offers up some hard-won consensus reality.

InDepth: How to Choose Your Dive Training by Rich Walker

Be sure to check out Stratis’ book, Close Calls, which details the close calls and near misses of more than 60 prominent divers who nearly lost their lives. If they made mistakes, you will too!

Stratis Kas is a diving instructor & explorer, a film-maker, adventurer and storyteller. Stratis Kas deals with all of his subjects — extreme weather expeditions to days lost in wilderness — with unique sensitivity and fearless focus. He travels to remote, sometimes risky, and often freezing locations to create stunning films that change what we know about diving expeditions.

Since 2016, he has led the Top2bottom cave filming team that specialize in Adventure Filming. In 2017, he finished his first film “Amphitrite” that won a finalist place in the film festival, “Short to the Point” in 2018. Currently he is finishing his second feature film “Infinite Liquid” produced by Because I Can Ltd.


How Deep Is Your Library?

Tech diving requires a deep body of knowledge that must be kept current. So it seemed appropriate to ask, what books should tekkies have on their shelves? To answer that question we turned to DAN’s nerdy risk mitigation coordinator cum cave diver, Christine Tamburri to suss out suitable tekkie tomes. Here is what she uncovered. Feed your head!




by Christine Tamburri. Header image: Jon Kieren catching up on his reading at Sistema Huautla by SJ Alice Bennett. Ed. note-Special thanks to Jason Brown for suggesting the topic.

The hallmark of a “super nerd” is typically the extent of their library. For row after row, their bookshelves overflow with everything from fiction to mystery to fantasy. Variety is the secret weapon. Deep down, tekkies are also super nerds with a diving addiction so, naturally, their bookshelves should also be overflowing with nerdy scuba works. Some books are a given, like the U.S. Navy Manual (First Edition – 1905), the NOAA Diving Manual (First Edition – 1975), The Silent World by Frédéric Dumas and Jacques Cousteau (1953), and Men Beneath the Sea by Hans Hass (1975). Others are not so obvious.

After countless conversations extending into the far reaches of the night with some of the industry greats, it became obvious that only a few books were well-known by divers around the world. Several were long forgotten or never discovered in the first place, and thanks to the input of Michael Menduno, Frauke Tillmans, Roger Williams, and Ken Sallot, this comprehensive list stands ready to help every tekkie become a super nerd. Even Rick Stanton himself crashed a virtual book club meeting to give his input on which books are most captivating.  

You are invited to take a deep dive (pun intended) into an extensive list of works that all tekkies should have on their bookshelves. Of course, hours upon hours could be spent discussing book after excellent book pertaining to the Andrea Doria, Wookey Hole, the Britannic, Great Lakes shipwrecks, such as Richie Kohler’s Mystery of the Last Olympian: Titanic’s Tragic Sister Britannic etc, but there is simply not enough time in the day or room on the page. As such, this list is not all-encompassing, but it is a solid foundation. A starter set of books if you will.

Classics from Early Tech

Some books age like fine wine. The longer they sit on the bookshelf, the more iconic they become. Some of these works are highly sought after and rarely available, but all are a time capsule of an iconic period in dive history. Taking things back to the early pre-scuba skin diving days,
Last of the Blue Water Hunters by Carlos Eyles (First Edition – 1985) is an epic recount of early breath-hold divers who ventured out into blue water in search of game, and in doing so, defied ancient myths and fears, and tested themselves in the process. It speaks to books like Shadow Divers by Robert Kurson (2004) and The Last Dive by Bernie Chowdhury (2000) document important times in the progression of wreck diving. They are often referred to as a “gateway drug” for those considering the leap into technical diving. Ultimate Wreck Diving Guide by Gary Gentile (1992) takes things a step further by detailing all aspects of wreck diving and how technology has thrust it into the mainstream.

A tekkie library would not be complete without a collection dedicated to the origins of the quest to go deeper for longer. Before founding TDI in 1994, Bret Gilliam wrote two books. Deep Diving by Bret Gilliam and Robert Von Maier with John Crea and Darren Webb (1992) discusses the transition from the recreational realm into the technical world, while Mixed Gas Diving by Tom Mount and Bret Gilliam (1992) discusses almost everything that divers need to know before venturing into the world of obscure breathing gas mixes.

Some years later, Doing it Right: The Fundamentals of Better Diving  by Jarrod Jablonski (2000) was published as a guideline for the gear configuration and training philosophies of Global Underwater Explorers (GUE). This work was updated in 2021 and the title was shortened to The Fundamentals of Better Diving.

Another classic published by a seriously busy pioneer in the industry is Technical Diving from the Bottom Up by Kevin Gurr (2004). Somewhere between building some of the first mixed gas computers and three different rebreather models (Ourobouros, Sentinel, and Explorer), Gurr found time to dive deep into technical diving while covering gear configurations, physiology, gas mixes, and a variety of other topics. Of course, this category wouldn’t be complete without mentioning a work that is defined by the word “classic”…aquaCORPS Journal by Michael Menduno (First Edition – 1990)! First introduced at DEMA in 1990, aquaCORPS revolutionized the technical diving world, uniting tekkies far and wide as they discussed topics that were seen by those not in the know as being incomprehensible. It was quickly followed by Joel Silverstein’s SUB AQUA Journal (1991), Curt Bowen’s Deep Tech (1995), and Bernie Chowdhury’s Immersed (1995), which was later purchased by Diver magazine.  

Got Your Meds?

Diving is one of the few sports that changes the physiological characteristics of the body. The changes that occur upon immersion are not simple to understand, so a true tekkie will add a few diving medicine books to their shelves. Physiology and Medicine of Diving by Peter Bennett and David Elliot (First Edition – 1969) and Diving Medicine by Alfred Bove and Jefferson Davis (First Edition – 1976) are seen as “bibles” to some physicians. These works would be carried around conferences with pride, as notes were feverishly taken and sections were enthusiastically highlighted. Even Jim Bowden would read Physiology and Medicine of Diving every day as he was preparing for his attempt to dive to the bottom of Zacatón. Very few will read these cover-to-cover, but their value as reference materials is unmatched, and they are a must-have to complete any tekkie library.

As an aside, a legend was recently lost as Professor David Elliot passed away on January 18, 2022. His legacy in dive medicine will continue to live on through his published materials. 

Gasses Galore

Nitrogen, oxygen, helium, argon, hydrogen…without them, the periodic table would be incomplete, and tekkies wouldn’t be able to satisfy their ever-present urge to submerge. In fact, these gasses are so important that they deserve a category of their own! Vance Harlow is responsible for one of the most sought-after gas mixing books ever written. Oxygen Hacker’s Companion by Vance Harlow (Fourth Edition – 2002) not only details how to mix nitrox and trimix, but it also dives deep into the dangers of handling oxygen and how to mitigate the risks. Many gas blenders agree that a shrine should be built to preserve the wonders of this book forever. The book is currently out of print, however, PDF copies do exist. Seek and ye shall find!

Once gas is mixed, accurate sensors must be used and thanks to Oxygen Measurement for Divers by John Lamb (First Edition – 2016), tekkies can learn more than they ever thought possible about the history, construction, and application of oxygen sensors. This is a must-read, especially for the rebreather divers out there. For those interested in the devastating effects of oxygen toxicity, the classic
Oxygen and the Diver by Kenneth Donald (1992) should be acquired and added to their bookshelf. This historically unique work is solely dedicated to the effects of oxygen on the diver, and it details studies that would definitely be shot down by Internal Review Boards if they were presented today.

The D-Word

Decompression and the corresponding theory are the foundation of technical diving. Decompression: Decompression Sickness by Albert Bühlmann (1983) was published during the midst of extensive research to understand how and why decompression sickness manifests. Basic Decompression: Theory and Application by Bruce Wienke (First Edition – 1991) is another comprehensive work that dives into the theory of decompression and covers topics such as modeling and diving at altitude. Wienke’s work forms the basis of NAUITEC’s decompression protocols and algorithm. Both of these books are integral to tekkie bookshelves as they are classic examples of the early days of decompression research, and they provide insight into how far the industry has progressed. Warning: There is heady math in both of these texts. Get ready to channel your inner Isaac Newton.

Deeper into Diving by John Lippmann (First Edition – 1990) is another early work that focuses on the various decompression tables. Included are the U.S. Navy, Bassett, NH-L, DCIEM, and RNPL/BS tables, just to name a few. A more recent work is Deco for Divers by Mark Powell (2008). This extensive book has it all, from medicine and physiology to modern day decompression procedures, and it is a must-have for anyone even half considering the leap into technical diving. Tekkies new and experienced will learn more than their brain can hold. 

Of course, tekkies cannot talk about decompression without mentioning decompression sickness…or “The Bends”, the “Rapture of the Deep”, “Satan’s Disease” or whatever nickname sounds best. Between the Devil and the Deep by Mark Cowan and Martin Robson (2021) is available in Europe now and set to hit US bookshelves shortly and promises to deliver an inside look into what it is like to battle and fight through a DCS hit at depth. 

Deeper and Longer

Whether it be climbing Mount Everest or descending into the depths of the Mariana Trench, humans have always been on a quest to push the extremes. For tekkies, the quest has revolved around the ability to go deeper for longer. At the forefront of undersea apparatus development was Sir Robert Davis, a well-respected inventor and businessman who wrote several works, including multiple volumes of Deep Diving and Submarine Operations (Fourth Edition – 1935). This book details the secrets of working at depth, such as compressed air operations, dive tables, and emergency procedures. A complete tekkie library needs to include the most classic of classics, and this certainly falls into that category. 

A more obscure and difficult book to find is Arne Zetterström and the First Hydrox Dives by Anders Lindén (1985). As the not-so-subtle name suggests, this work is about two things…. Arne Zetterström and his adventures using hydrox (hydrogen and oxygen) to push the limits! This interesting gas mix is not a thing of the past, but an innovation for the future. With the helium shortage, hydrogen may be the solution for über-deep dives, and this is a must-read for the futuristic tekkie who wants to learn more about where technical diving may progress in the coming years.

In lieu of hydrogen, an alternative solution to the helium conundrum may be atmospheric diving suits (ADS), aka exosuits that are currently being developed by Nuytco Research, Vancouver, Canada. The history of these unique devices can be read about in Ironsuit by Gary Harris (1994). [Ed.note—Watch this space. InDepth is planning a feature story on the state of the ADS nation in a coming issue. Is there an Exosuit in your future? Find out.] Of course, old fashioned helium tends to do the trick most of the time, and tekkies can read all about one woman’s quest to become the deepest in Fatally Flawed by Verna van Schaik (2010). 

A final ode to the depths that should rest on all tekkie library shelves is Living and Working in the Sea by James Miller and Ian Koblick (1995). This book encompasses all things saturation diving, from the complete system to the operations to the science. Tekkies may understand the basics of how saturation systems function, but this work will kickstart learning and highlight how physiology, science, and industry combine to make seafloor operations possible. 

Notes from the Underground

Cave diving is not a sport of the modern day. In fact, the first known “cave dives” took place in the 1800s and early explorers used freediving techniques or surface-supplied air to wander into the underwater, underground world. Since then, pioneers of the sport have come and gone, and techniques have developed and been modified through time. A true tekkie will revere cave diving to the level that it so rightfully deserves, and a section of their library will be solely dedicated to this quirky subsect of technical diving. 

Starting things off with a history lesson, The Darkness Beckons by Martyn Farr (1980) details the history of cave diving around the world. Included are details about exploration projects at Wookey Hole (UK) and Pozo Azul (Spain), as well as recounts about record-setting dives by pioneers of the sport. A complimentary book is A Glimmering in Darkness by Graham Balcombe (2007) which discusses the origin of the Cave Diving Group (CDG) and how cave diving was a natural transition for British dry cavers on their quest to explore sump systems around Europe. 

Exploration and caves go together like helium and an empty bank account. Drawn to the Deep: The Remarkable Underwater Explorations of Wes Skiles by Julie Hauserman (2018) and
The Wakulla Springs Project by William Stone (1989) discuss exploration efforts that significantly impacted the cave diving world and shed a positive light on the sport. On the flip side, Beyond the Deep by Barbara Anne Am Ende, Monte Paulsen, and William Stone (2002) is a recount of a dark time in the sport when a deep cave exploration project at Sistema Huautla in Oaxaca, Mexico turned deadly. Super nerds will find interest in all of these works regardless of whether the ending was joyous or tragic. 

His Sheckness

Sheck Exley is often referred to as the greatest cave diver to ever live, and not without strong merits to back the claim. He was the first person to log 1000 cave dives, he was responsible for developing the fundamental rules of cave diving, and he was an explorer who mapped countless caves in North Florida. A legend was lost on April 6, 1994, when Sheck died while trying to find the bottom of Zacatón in Northeast Mexico. Luckily for us, he left behind several works that are still considered gospel by cave divers around the world. 

One of the most iconic cave diving books ever written is Basic Cave Diving: A Blueprint for Survival by Sheck Exley (First Edition – 1979). Almost every cave diver was instructed to read this book early in their training, as it gave them an in-depth look at the five basic rules of cave diving: Training, Guideline, Air, Depth, Lights. This work did go further and cover everything from anti-silting techniques to procedures for handling a “berserk diver,” but the five rules are the main takeaway for most readers. This is a staple for any tekkie library, and it is quite literally the foundation on which modern day cave diving is built. 

Sheck also wrote a few memoirs where he talked about his life, his initial training, the early days of cave exploration, and the birth of cave diving techniques and philosophies.
Caverns Measureless to Man by Sheck Exley (1994) is iconic, but difficult to find, even in the used book market. It details cave diving through the eyes of Sheck, and it tells the story of those that lost their lives on a quest to explore the underground world. Taming of the Slough by Sheck Exley (published posthumously in 2004) is slightly more specific in that it recounts the exploration at Peacock Springs. This immense cave system is an unofficial rite of passage for Florida cave divers, as its history is as vast as its passages. A tekkie library wouldn’t be complete without a section solely dedicated to the life and accomplishments of one of the greats, and only a true super nerd would dare to track down every book ever written by the legendary Sheck Exley. 

In The Loop

As more and more people dive into the world of rebreathers , it would be unfair to exclude two books written about this futuristic, bubble-less world. Amongst the countless accomplishments of Jeff Bozanic, he wrote one of the most comprehensive rebreather books available. Mastering Rebreathers by Jeff Bozanic (2002) dives deep into topics like the types of rebreathers that are available, the long-term maintenance requirements, emergency procedures, and travel considerations. Similarly, The Basics of Rebreather Diving by Jill Heinerth (2013) discusses the history of rebreather diving, while providing real-life stories of its applications in her own diving career. {Ed.note: And there is always InDepth’s “Holiday Rebreather Shopping Guide,” to view rebreathers on the market and compare their speeds and feeds, err, specs.

Safety First

All divers, especially tekkies, should be constantly learning. Whether in the water or in the library, there is always something new to discuss, practice, and understand. On that same note, every diver is also susceptible to human error, and the lessons learned from near-miss and fatal events are valuable learning tools. Under Pressure by Gareth Lock (2019) is a collection of thoughts and discussions on how human factors play a role in incidents and accidents. It also summarizes the importance of creating a “just culture’” in the dive community so that adverse events can be analyzed without judgment.

Part of this culture is creating a safe space for divers to admit their mistakes. Close Calls by Stratis Kas (2020) is a collection of harrowing stories by some of the biggest names in the dive industry as they recount an incident or series of events that nearly resulted in their injury or death. If you are a super nerd with a hectic life that doesn’t have time to read an entire book cover-to-cover in one sitting, fear not! Each story in this book will only take 5-10 minutes to read, so there is no excuse to not add this work to your tekkie library.

Another book of great value to the safety-conscious super nerd is The Six Skills and Other Discussions by Steve Lewis (2011). This book will discuss all the topics that are left out of textbooks. There is never anything wrong with bookshelves that are overflowing with materials that are focused on safety, because a super nerd is always learning. 

Get Off My Back

Sidemount, seen by some as our savior from above and seen by others as the unnecessary red-headed stepchild. Regardless of how it is viewed, sidemount is an important component of the modern dive industry, so not surprisingly, there are several books dedicated to the craft. One of the earlier books written solely about this configuration is Sidemount Profiles by Brian Kakuk and Jill Heinerth (2010). For something a little more recent, a tekkie may prefer to dive into Sidemount Diving: The Almost Comprehensive Guide by Rob Neto (Second Edition – 2020). It is no secret that sidemount is finicky and requires patience to perfect. Having access to solid reference materials can make this process slightly more enjoyable, but let’s be honest—you aren’t really a sidemount diver until you’ve spent hours upon hours making minor tweak after minor tweak into the early hours of the morning. 

Young Guns

There are several books that are new to the game, but not late to the party. These books aren’t written for the youth in the industry, nor were they written by newcomers. Simply put, they were recently published and quickly sailed to the top of the charts, as they are masterpieces printed in black and white. Starting out strong with an author who is highly influential to women in diving and those seeking to get involved in exploration projects, Jill Heinerth’s autobiography is a compelling tale about her life as a cave diver. Into the Planet by Jill Heinerth (2019) should be in every tekkie library regardless of gender, because the lessons learned and the stories portrayed are captivating and inspiring to all. 

In terms of recent events, few will compare to that of the 2018 Thailand cave rescue. If for some reason you haven’t heard about this, it will be assumed that you are living under a rock. To summarize, 12 young boys and their soccer coach were trapped in a flooded cave for 18 days and were miraculously rescued by a team of cave divers.  Several books were written about the event from the perspective of some of the divers. The Aquanaut by Rick Stanton and Karen Dealy (2021), Against All Odds by Richard “Harry” Harris and Craig Challen (2019), and Thirteen Lessons that Saved Thirteen Lives by John Volanthen (2021). All of these books retell the harrowing tale of how a group of weekend warriors happened to have the right skill set for the job because of their obscure hobby. They detail the rollercoaster of emotions that were endured and the tough decisions that were made. Every tekkie, regardless of their level of interest in cave diving, will find enjoyment, exhilaration, and inspiration in the pages of these books.

Something Fun

As mentioned early on, variety is the secret weapon to creating a solid tekkie library. Almost every work that has been discussed thus far is semi-serious in nature, so it is time to add a little fun into the mix! Dining with Divers: Tales from the Kitchen Table by David Strike and Simon Pridmore (2017) is a compilation of short stories from legends in the dive industry that conclude with their favorite home-cooked recipe. This is certainly a quirky book, but nonetheless unique. Moving on to fiction, the Mer Cavallo Mystery Series by Micki Browning is written by a diver for divers. Adrift (2017) and Beached (2018) will take readers on a rollercoaster ride that is filled with ghostly tales of the Spiegel Grove and Spanish galleon treasure. For the tekkie with diversified interests, The Jason Parker Trilogy by Dr. John Clarke has it all: undersea habitats, deep sea hydreliox diving, aliens, and even romance! All tekkies should grab a copy of Middle Waters (2014), Triangle (2017), and Atmosphere (2019), and experience the writing of a Navy diving and aviation scientist. 

A more extensive collection of novels is the Mike Scott Thriller Series by Eric Douglas. Readers will be taken from Cayman to Hollywood to Mexico as they follow Mike Scott on his diving adventures around the world. Of course, nothing ever goes to plan, so buckle up for yet another rollercoaster ride of events. The super nerds out there will be sure to stock their bookshelves with all 11 books: Cayman Cowboys (2005), Flooding Hollywood (2006), Guardians’ Keep (2008), Wreck of the Huron (2012), Heart of the Maya (2014), Return to Cayman (2015), Oil and Water (2016), The 3rd Key (2017), Turks and Chaos (2017), Water Crisis (2018), and Held Hostage (2021).

The author geeking out in the DAN library.

For SUPER Super Nerds Only

This final section deserves a disclaimer…super nerdiness lies ahead. There are a number of forums and discussions that have been held over the years that covered topics from deep sea diving to rebreathers and everything in between. All of these were presented in-person, but luckily, über passionate people exist and they took the initiative to publish everything that was discussed. A tekkie should have a proceeding or two on their bookshelf, and although there are a lot to choose from, a few stand out from the rest. A true super nerd will acquire them all.

For those wanting to learn more about deep diving and the techniques required to do it safely, Hydrogen as a Diving Gas Proceedings of the 33rd UHMS Workshop, Wilmington, NC (February 1987), Proceedings of Advanced Scientific Diving Workshop, Smithsonian Institution, Washington, DC (February 2006), Technical Diving Conference Proceedings, DAN, Durham, NC (January 2008), and Techniques for Diving Deeper than 1,500 Feet, UHMS, Bethesda, MD (March 1980) may be of interest.

If bubbleless diving is more your speed, Proceedings of Rebreather Forum 2.0, Diving Science and Technology, Redondo Beach, CA (September 1996) and Rebreather Forum 3.0 Proceedings, AAUS/DAN/PADI, Orlando, FL (May 2012) should definitely be added to the library. And lastly, for super super nerds with an interest in flying after diving or the nerdy science behind dive computers, the Flying After Recreational Diving Workshop Proceedings, DAN, Durham, NC (May 2002) and the Proceedings of Dive Computer Workshop, AAUS, Santa Catalina Island, CA (September 1988) are perfect reading materials before bed. A tekkie library wouldn’t be complete without at least one of these proceedings, but the more the merrier! 

Your Tekkie Library

Against All OddsMixed Gas Diving
A Glimmering in DarknessNOAA Diving Manual
aquaCORPSOxygen and the Diver
Arne Zetterstrom and the First Hydrox DivesOxygen Hacker’s Companion
Basic Cave Diving: A Blueprint for SurvivalOxygen Measurement for Divers
Basic Decompression: Theory and ApplicationPhysiology and Medicine of Diving
Between the Devil and the DeepProceedings of Advanced Scientific Diving Workshop
Beyond the DeepProceedings of Dive Computer Workshop
Caverns Measureless to ManProceedings of Rebreather Forum 2.0
Close CallsRebreather Forum 3.0 Proceedings
Deco for DiversShadow Divers
Decompression: Decompression SicknessSidemount Diving: The Almost Comprehensive Guide
Deep DivingSidemount Profiles
Deep Diving and Submarine OperationsTaming of the Slough
Deeper into DivingTechnical Diving Conference Proceedings
Dining with Divers: Tales from the Kitchen TableTechnical Diving from the Bottom Up
Diving MedicineTechniques for Diving Deeper than 1,500 Feet
Drawn to the Deep:The Remarkable Underwater
Explorations of Wes Skiles
The Aquanaut
Fatally FlawedThe Basics of Rebreather Diving
Flying After Recreational Diving Workshop ProceedingsThe Darkness Beckons
Hydrogen as a Diving Gas Proceedings of the 33rd UHMS WorkshopThe Fundamentals of Better Diving
Into the PlanetThe Jason Parker Trilogy
Ironsuit The Last Dive
Last of the Blue Water HuntersThe Silent World
Mastering RebreathersThe Six Skills and Other Discussions
Living and Working in the SeaThe Wakulla Springs Project
Men Beneath the SeaThirteen Lessons that Saved Thirteen Lives
Mer Cavallo Mystery Series: AdriftUltimate Wreck Diving Guide
Mer Cavallo Mystery Series: : BeachedUnder Pressure
Mike Scott Thriller SeriesUS Navy Manual

Christine Tamburri is the Risk Mitigation Coordinator at DAN. She began diving in 2016 and never looked back, spending weekend after weekend diving as much as possible while meeting industry leaders along the way. After graduating from Penn State University in 2020, she decided that a full-time job in the industry was her calling and she became a summer intern at DAN. Later that year, she was hired into her current role where she develops e-learning courses, assists first aid instructors worldwide, and designs risk assessment tools for dive operators and professionals. Christine is an avid cave and technical diver who spends every spare moment of her free time either cave diving or planning to go cave diving.

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