What It Takes To Lead A Technical Diving Team


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.

Let’s start by pointing out that one of the guidelines TDI promotes in its technical manuals 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 link 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 TDI 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. First, she will not be lead into a situation which she finds uncomfortable. Second, 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 and 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 TDI instructor!

Contact Jeff or SDI TDI and ERDI
If you would like more information, please contact our World Headquarters or your Regional Office.
Tel: 888.778.9073 | 207.729.4201
Email: Worldhq@tdisdi.com
Web: www.tdisdi.com
Facebook: www.facebook.com/TechnicalDivingInt

Traveling with a rebreather

Traveling With a Rebreather

Posted on: April 12, 2013


With airlines tightening luggage restrictions, packing for a dive trip is hard enough with just recreational gear and traveling with a rebreather adds another level of difficulty.  What to bring, how to pack it, will the dive center have everything I need when I get there?  These are all questions that need to be addressed, but if you tackle them one at a time, you’ll realize traveling with a rebreather can be very simple.

“What should I bring?”  This question goes hand in hand with “will the dive center have what I need when I get there?”  The first step in determining what to bring on the plane with you should be finding out what the dive center has available.  Most dive destinations around the globe now have at least one or two “rebreather friendly” dive shops.  It’s very important, however, to call and verify that they can accommodate you.  Do they have the correct cylinders for you?  Do they stock sorb?  Do they have bailout cylinders available?  Do they have high pressure O2, and can they blend the diluent you need?  It is very crucial to ask these specific questions, as many dive centers advertise themselves as “rebreather friendly,” but in reality are just “rebreather tolerant.”  Once you know for sure what the dive center is able to provide, the next step is figuring out what you need to bring.  If you are traveling to a remote destination, you may experience a bit of sticker shock when you see what they will charge for sorb and cylinder rental.  It’s important to remember that many remote locations (especially islands) incur huge shipping charges and import taxes, and these costs are often passed on to the end user.  It may seem cheaper to bring your own cylinders and sorb, but this typically ends up being more hassle than it’s worth.  We recommend traveling light and supporting the local dive center by renting/buying from them.

“How do I make all THIS fit in THERE?”  It can seem like a daunting task when all your dive gear is laid out in front of you, and you have only a few small bags to fit it in.  However, there are a few tricks to helping you get everything you need to where it needs to go safely.  Try to carry on as many of the critical components as possible.  Things like the head, canister, loop, counter lungs, mouthpiece/BOV, regulators, and electronics can easily be damaged/lost in checked luggage and leave your unit inoperable, so it is best to carry them on.  Things like wings, harnesses, fins, masks and exposure suits are pretty resilient to rough baggage handlers and can usually be rented at your destination if they go missing.  If you must bring cylinders and sorb with you, it is typically best to check them.  Just be sure to include a Material Data Safety Sheet with the sorb and remove the valves from your cylinders.  You are required to leave the cylinder openings unobstructed so they are easily inspected; agents have been known to simply confiscate/dispose of cylinders when this rule is ignored.  It is always a good idea to photograph everything as it is being packed, this way you have evidence if something is lost or damaged by the airline.  The fee for an extra bag is typically less than for an overweight bag, so it’s not a bad idea to bring along a small mesh dive bag that you can pull out and transfer gear into if you end up overweight at the ticket counter.

So everything is packed up, you’re at the airport, bags checked, and you’re going through the TSA checkpoint.  As long as you remembered to remove any tools or knives from your carryon, things should go pretty smoothly.  It can be fun to watch the look on the TSA agents face as your bag goes through the scanner, but after a quick inspection there usually is not an issue.  Remember, they are just doing their jobs, and a rebreather head and scrubber canister looks pretty suspicious on an x-ray.  We have found many TSA agents are now recognizing rebreathers, especially in popular hubs to dive destinations.  Just assume that your bag will be inspected and plan a few extra minutes to allow for this.

So you know you’ve brought everything you need to enjoy a great holiday with your rebreather and all your critical rebreather components have made it onto the flight with you.  Now it’s time to sit back, relax, enjoy the flight, and have a great trip.

Contact SDI TDI and ERDI

If you would like more information, please contact our World Headquarters or your Regional Office.

Tel: 888.778.9073 | 207.729.4201

Email: Worldhq@tdisdi.com

Web: www.tdisdi.com

Facebook: www.facebook.com/TechnicalDivingInt

Air Management



By Steve Lewis

You may have sat-in on dive briefings that end with the advice: “Please come back on board with at least 50 bar of air in your tanks (500 psi from US divemasters)… have a good dive.” As far as it goes, not a terrible thing to tell the average sport diver, but does it go far enough?

Ask a technical diver that question, and my bet is you’d get a resounding NO!

There are plenty of ad-hoc definitions pointing out the differences between a sport dive and a technical one, but certainly one of the most telling signs is that the dive plan for a technical dive is a bit more complex than a simple: “Let’s come back with 50 bar in our tanks!” In truth, most technical divers would get sweaty palms when the needle on their SPG hovers close to that level.

From the very start of technical dive training – a TDI Intro-to-Tech program for example – there are two basic rules that instructors and textbooks hammer away at constantly. One is a slight modification of the first rule of scuba “Never hold your breath: keep breathing.” That advice is still valid but in tech diving it becomes: “Always have something appropriate to breathe, because running out of air/gas is NOT an option.”

The second rule deals with trouble in the water. It states: “If something goes wrong at depth, it’s best to fix it at depth, because bolting to the surface is not an option!”  Because of rule one and two, it becomes apparent that proper gas management is somewhat more detailed than taking an occasional glance at an SPG, and as students in their first tech class learn, it takes planning and a little work to stay safe, but the benefits are well worth the effort.

Let’s take a brief look at what’s involved.

Gas management, or more precisely gas volume management, starts with knowing your personal gas consumption rate. It does not matter if you work in cubic feet or litres, the important starting point is to have a figure based on your actual breathing rate.

There are several ways to collect this information. Some TDI instructors ask Intro-to-Tech students to average out actual consumption from previous dives, but most will have students do “data collection” at a set depth for a specific time, noting starting and ending pressure. Back on the surface, these numbers are manipulated a little and used to produce a Surface Air Consumption (SAC) rate. This is the baseline number that will be used in future dive plans.

Some divers (and some instructors… me included) will take the calculation for this baseline even further, and will actually monitor resting consumption rate on the surface while doing nothing more energetic than watching a video or reading a book.  This number has to be modified with some extra loading to take into account the fact that diving puts a bit more strain on the body than sitting reading a book, but in my opinion, gives cleaner starting data.

Whichever method is used to arrive at the baseline, that baseline becomes a constant and we can plug it into all future dive plans. For the record, an average baseline SAC for a relatively experienced diver is around 14-16 litres, or about 0.5 to 0.6 cubic feet, a minute, and in many textbooks, a figure within this range is used for most examples.

The next step is to include the parameters of the dive into the gas management plan. The effects of depth, workload, and other dive factors such as water temperature, visibility, and so on are also considered.

These can vary tremendously. For example, one dive to exactly the same depth as another may require twice as much gas because of stressors such as poor visibility, colder temperatures and current.

At the end of this set of calculations including these highly variable “Dive Factors,” we have converted our SAC rate into something we typically call our Required Minute Volume (RMV). In other words, for a moderately simple dive to 30 metres or 100 feet, our average 14 litres or half a cubic foot of gas needed on the surface per minute can easily become 124 litres or 4.5 cubic feet of gas needed per minute.  That’s a big jump, but perhaps not a surprise.

The final step in this part of the planning process is to multiply our RMV by the scheduled time at depth.  Let’s say we intent to spend 30 minutes on the bottom.  Armed with this knowledge, we can multiply our RMV by 30 to arrive at the required volume of gas needed for the dive… in our example this final figure would be around 3700 litres or 135 cubic feet.

However we slice it, that is a lot of gas, and let’s remember that’s only the gas needed for the bottom time; we have to also consider the gas required to get back to the surface. More calculations including knowing what decompression stops we have to make on the way up and for how long… and what type of decompression gas we are going to use!

On top of all this, we also follow the golden gas management rules of technical diving: The Rule of Thirds for back-gas and the Rule of Halves for decompression gas.

Essentially (and in its simplest form) the Rule of Thirds states that we use one third of our starting volume for the first half of our bottom time (the swim in), one third for the second half (the swim out), and the final third as contingency gas. In effect, that last third belongs to our buddy, and remains untouched at the end of the dive (barring emergencies).

The Rule of Halves says that we take at least twice as much decompression gas on the dive as the plan calls for. This way, we have lots to share and lots of spare air if we get a free-flow or if we have to spend a little longer than planned decompressing.

The final cherry on top of the ice-cream sundae is matching up gas consumption to waypoints on the dive itself. For example, using the case of our 30 metre/100 foot dive for 30 minutes, we would probably have several “Go or Go Home” checkpoints earmarked. At a minimum, these would include one for arriving at depth, one for arriving at the focus of our dive, one for the turn-around point, and one for arriving back at the ascent point.

These waypoints would give each team member an opportunity to say: “Yep, I am fine, let’s go ahead,” or not depending on how they’re feeling and how their kit is behaving. In addition, it gives each team member an opportunity to check his or her actual gas consumption against the expected or budgeted gas consumption used in the dive plan. Their SPG should be used to confirm what they expect to see… and to do this we must first have done some calculations to translate volume into a reading on that SPG. For example in a pair of 14 litre cylinders, a one bar drop in our SPG translates to 28 litres of gas consumed. The calculations for imperial units is less simple, but inevitably we have to be able to read a gauge and work out for every 100 psi drop, we have burned through X number of cubic feet.

If this is starting to sound rather complicated, it is, but it’s not possible to explain a whole TDI course module in a few paragraphs… you have to take the course! And let me assure you that gas volume planning is far easier to manage than an OOA situation at depth when you have a serious decompression obligation to fulfill!

Take care and dive safe.

Steve is an active cave and wreck diver and instructor-trainer with SDI/TDI. He writes extensively on technical diving, diver safety, and risk management for open-circuit and closed-circuit diving. He has served on TDI’s TAP (Training Advisor Panel), and works as a marketing and product development consultant in the dive industry.

Contact TDI SDI and ERDI

If you would like more information, please contact me.

TDI Advanced Nitrox on line is now available!


The SDI IDC and IEC is now online!


If you need more info, contact me at tdisdiit@thefundiver.com




New Updates

Hi everybody,

I am updating the site.


May I present you……………….




Regula and Jeff proudly present you Enya. Enya is born September 1, 2011 on Bonaire. Her weight is 3070 grams and she has a length of 48 centimeters.

Some more pics on the pictures page.

SDI Instructor Course


So you’re ready for the next step and to get the chance to introduce new divers to the sport of Scuba diving, see the looks on their faces the first time they breath underwater or see things they have only seen in movies and on TV.  Maybe you want to become an SDI Instructor to start or change careers or so you can travel the world.  The SDI Instructor Course will teach current Divemaster or Assistants Instructors the knowledge to safely function as an SDI Instructor with the abilities to teach SDI Open Water Scuba Divers, Advanced Adventures Divers, Rescue Divers, Divemasters and Assistant Instructors. The program is divided into two sections, an Instructor Development Course (IDC) and an Instructor Evaluation Course (IEC).
The IDC teaches you how to;

  • Schedule course
  • Successfully market scuba
  • Properly teach and design academic and in water sessions
  • Effectively utilize assistants.

The IEC evaluates everything you learned during the IDC.  This is typically a two day evaluation process and evaluates your abilities in:

  • Preparing and teaching academic sessions
  • Knowledge of subject matter
  • Pool/confined water lessons
  • Open water lessons
  • Emergency management abilities

For more info leave an replay or send an email to tdssdiit@thefundiver.com

TDI / SDI Instructor Trainer

Friday, the 12th of August I had been certified as an TDI / SDI Instructor Trainer / Certifier. It was a hell of week. Long days, intensive!

We had a nice bunch of people. Everybody was well motivated and everybody got certified as a TDI / SDI Instructor Trainer!

From left to right: Flemming Elleboe,Chairman Board of Directors IT- Astrid de Jager- Rob van de Vechte- Chris Verstappen- Steve Moore, TDI / SDI Instructor Trainer Evaluator HQ- Jeffrey Kempff- Alex van der Kroft

Enjoying this day!!!