ENTRY-LEVEL TECHNICAL DIVING courses exist to introduce recreational divers to the additional complexities of increased oxygen percentages and kit configurations.
A number of training agencies offer such courses. I have limited myself to three well-known names, IANTD, PADI and TDI, though you may also want to consider what ANDI, BSAC, GUE, IART, RAID and others can offer.
I wanted to explore the prerequisites for entering the tec world – the course subject matter, student materials, skills performed during courses, and how all this might vary from agency to agency.
So I asked three big tec cheeses effectively to convince a new student to choose their agency’s courses over others.
After 30 years, IANTD (International Association of Nitrox & Technical Divers) is arguably the oldest of the three agencies in terms of tec, and describes itself as “the leader of diver education”. Many of its own leaders have gone on to work for other technical agencies.
Instructor Trainer Christian Heylen, a member of the Board of Advisors of IANTD Worldwide, told me that the agency’s procedures were developed with the help of the National Association for Cave Diving and National Speleological Society’s Cave Diving Section.
It all kicks off with its Tek Lite courses (Advanced Nitrox or Advanced Recreational Trimix). Advanced Nitrox “covers the core skills from the technical diver training programs, including the use of dual-outlet single cylinders or twin-sets with central isolation manifolds and decompression skills and procedures using bottom mixes up to 40% nitrox and decompression mixes up to 100% oxygen to a maximum depth of 42m.”
The Professional Association of Diving Instructors, the world’s largest diving agency, may be “the way the world learns to dive”, but PADI is by no means the biggest agency in technical training.
It began to design its TecRec range only in 2000, and has a Technical Diving Division “utilising both internal and external experts in technical diving, diving medicine, equipment and instructional design”.
You can begin with either Discover Tec Diving or Tec 40. The latter “provides a transition from rec to tec and bridges the gap to full technical deep decompression diving. You gain experience and begin building tec-diving knowledge and skills.”
The qualification enables limited decompression dives to 40m.
Technical Diving International was formed by two huge names from Florida cave-diving, Bret Gilliam (previously of IANTD) and Mitch Skaggs. TDI has run since 1994 and its sister recreational wing SDI came along four years later.
Mark Powell, a TDI Instructor Trainer and Training Advisory Panel member, says that before instructors go on to more advanced tec instruction “they must have a wide range of experience of teaching the entry-level tec courses” – an approach designed to eliminate the zero-to-hero philosophy and inexperienced tutors.
TDI offers a course called Intro to Tech, but you can begin with either Advanced Nitrox or Decompression Procedures (the latter on condition that you use only air or a weak nitrox if not trained in blends over 40%.)
Advanced Nitrox qualifies divers to use nitrox from 21-100% within their current certification level to a depth of 40m on dives that don’t require staged deco.

Manuals & Theory
The three agencies cover much the same theory topics on their courses. There are sections covering physics and physiology – including the effects and dangers of both oxygen and nitrogen, and decompression illness – equipment options, oxygen safeguards and dive-planning.
Each agency provides deco tables in their manuals’ appendices or as an additional part of the training materials.
IANTD’s Tom Mount created his own air decompression tables for use with a 50% deco gas. PADI encourages the use of deco software but does provide tables to help students convert depth to pressure. There are also a multitude of tables listing gases from 21-100% to allow students to check partial pressures and gas loadings.
Do these eliminate use of a calculator? No, the student still needs to understand the concept behind them.
They do however reduce the chance of human error. TDI expects the student to use Buhlmann for review questions but also provides other tables such as US Navy and DCIEM.
IANTD’s Advanced Nitrox manual is available as a PDF e-manual, and has seven nicely laid-out chapters with good-quality colour photos and illustrations. The manual and accompanying tables are referred to as a Student Kit. I recommend that students read the chunky 124-page document before starting the course.
There are currently no knowledge reviews, because theory has to be completely reviewed by the instructor (so no e-learning is available) but Course Preparation Workbooks are set to be available for every IANTD course later in 2016. The multiple-choice 25-question exam requires a passing score of 80%.
You use IANTD dive-planner work-sheets (referring to tables and using calculations taught during the course) and some questions are written as scenarios that require the diver to choose the best option in emergencies.
“Training today is more focused on skills to prevent emergencies,” Heylen told me. “Equipment still fails but most of the time the emergencies occur because of diver failures.”
PADI’s Digital Manual has been around since late 2013. Before then students were expected to have the old Tec Deep Diver Manual, and were sent handouts from the dive-centre with which they would take the course – a lot of reading. Now it’s recommended to complete only the first three chapters, and handouts direct the student to pages relevant to Tec 40.
There are seven handouts, with independent study assignments (quiz questions) and three knowledge reviews.
A 50-question multiple-choice exam has to be completed with an 80% pass rate as standard, and the student should refer to tables in the appendix of the manual.
This is still a massive amount of information for the candidate to absorb, and I recommend that all reading be completed before attending class.
Do buy your Crew Pak before reaching the dive-centre if you’re taking Tec 40 abroad, because the DVD provided won’t fit into your tablet!
Your instructor will also introduce you to planning dives on a PC as part of the Practical Application exercises. Vikki Batten, a PADI Technical Diving Division member and Rebreather Technologies Director, is excited that the technology has progressed so much: “Now we have our dive-planning software on smartphones and tablets that are always with us, and there are a multitude of suitable dive-computers to choose from.”
PADI does what it says on the tin, and if candidates like the style of matching sections within a training manual to a DVD chapter and subsequent knowledge-review questions, this “multi-media learning experience” will appeal.
Sadly neither e-learning nor the Touch digital product is available yet for the TecRec range.
TDI’s manual is more compact, is easy to navigate and review questions come at the end of each of the 10 chapters. The student is expected to fill in the blanks in answering questions.
This style of “comprehension” requires students to return to chapters to locate the correct answers, which provides an element of confirmation in understanding and reference.
The manual’s quality is disappointing, however. There are no colour photos and the pages come out easily from the spine – frustrating when you need to refer to pages over and over again!
The 30-question multiple-choice Open Book exam demands an 80% pass rate, and the candidate should complete a number of calculations on dive-planning. Open Book tests allow the student to refer to the correct section of the manual, so removing stress from traditional exam conditions.
This back-to-basics style of learning is nicely combined with what Mark calls “sophisticated tools” such as dive-computers, different decompression strategies and software programmes.

Gone are the days of Nazi-style technical instructors who cut their teeth in the Navy. Instructors no longer rip off their students’ masks or turn off their valves to instigate survival instinct.
Today, you are more likely to be flashed a pre-written card showing a simulated emergency, and given time to prepare a response with your team.
IANTD says that techniques are constantly being re-evaluated to line up with developments in equipment and procedures. All skills must be taught or practised in a pool or confined water before moving on to the open-water dives.
A set of Watermanship tests need to be completed before certification to ascertain that the student is fit and mentally able to deal with emergencies. The student then signs against his or her performance.
Is this a bit extreme for entry-level tec training, or does it reduce the potential for accidents? I’m impressed, because it won’t have been since learning to dive that we will have done a full set of confined-water dives or swim tests!
Technical divers are taught to err on the side of caution, demonstrate good judgment and manage stress. These extra safety measures seem to be a way for the instructor to determine whether or not a candidate has what is needed to take diving to the next level.
“Employ precision buoyancy control and demonstrate proficiency in a variety of dive techniques” are requirements fairly open to interpretation, but IANTD prides itself on having experienced instructors who should have a plethora of skills.
I find it odd that finning techniques are not mentioned in required skills training. Back-finning away from your team-mates on ascent and being able to “turn on the spot” to see a member of your team who may have strayed into your blind spot are – in my opinion – important skills.
What I do like is the standard required of one of the Watermanship skills deploying a lift-bag and reel: “maintaining a tight reel and neutral buoyancy.” Some other agencies allow this skill to be done from the bottom, which requires no buoyancy skill.
The PADI instructor manual states that: “An individual who’s still mastering the fine points of recreational diving is not ready for the higher skill and knowledge demands of tec diving”.
Assuming that this means primarily buoyancy skills, it’s refreshing to see that one prerequisite for starting this course is the Deep Diver speciality. During this you would hope that the instructor has ensured a certain level of buoyancy competence getting to, at and ascending from, 40m. But why not then the Peak Performance Buoyancy speciality?
“The most important inwater skill is always buoyancy control,” Vikki Batten told me. “Trim and fin techniques are also fine-tuned. The last layer of complexity is dealing with emergencies, team-awareness and communication”.
However, of the whopping 17 skills required for Dive 1 of Tec 40, only two directly require the student to demonstrate buoyancy skills (plus pre- and post-dive weight checks). Having said that, one of these requires maintaining a depth for a full 8 minutes, which is going to be challenging (rightly so) for someone in a twin-set for the first time.
“Learning basic finning techniques starts at Open Water Diver, with more advanced techniques introduced during other recreational and TecRec courses,” said Batten. I couldn’t find any finning techniques listed on the instructor skill slates for this range but in a recent blog she states: “Now we can make it easier for divers to master neutral buoyancy and a good diving position if we introduce them to it as early as possible throughout training.”
The number of skills to be mastered during Tec 40 does reduce over the next three dives but dive two is still in double figures. Tec Deep instructors can also add simulated emergencies for students on dives, in addition to the vast amount of skills listed on their teaching slates!
Tec 40 wasn’t necessarily designed to be completed in three days, but in many resorts you’ll find that this is the case.
The instructor will then have to combine theory, practical applications, skills and the mandatory depth restrictions with the restrictions of time, even though Batten insists that the course “takes as long as it takes”.
TDI’s courses and materials are constantly being updated “to ensure that they’re up to date and consistent with current technical-diving protocols”. The instructor manual states that: “Even the best program of instruction is only as good as the people who present it”. So with just eight inwater drills listed in the instructor manual, you could either get a very thorough course focusing on repetition and practice, or a very dull course, depending on the quality of your instructor.
No skills listed relate directly to finning techniques, but you must “demonstrate buoyancy control, maintain position in the water column during skills”, “demonstrate correct trim and horizontal body position” and “show good awareness of buddy and other team-members through communications, proximity and team-oriented dive practices”.
An additional Skills Challenge document allows the TDI instructor to test the student on procedures learnt on courses (called No Excuses) and, for later courses only, Multiple Failures may be added during dives.
TDI does not specify depth standards for each dive as PADI does, but I wouldn’t necessarily trust an instructor who took me to 40m on dive number 1!
Mark Powell believes that “being able to deal with problems, while maintaining buoyancy and buddy awareness, is a key skill, as all problems must be dealt with in the water without breaking decompression ceilings or oxygen toxicity floors”.
Both PADI and TDI use acronyms to help students remember procedures for pre-dive checks and for gas-switching. PADI even provides these as neat check-lists on wipe-clean slates to be ticked off with a pencil.
In entry-level Open Water courses acronyms are encouraged as a learning tool. I like these repeatable procedures even at this level of diving, especially with regards to safety.
All three agencies allow these courses to be taught with a single cylinder (Y- or H-valve) combined with pony bottle or as a twin-set configuration or sidemount. Each agency has its own version of Advanced Nitrox or Tec 40 that can also be taught on a rebreather, showing how technology has progressed in the past 10 years.
The percentage of nitrox blends varies, as do partial pressure limits and maximum depths (see table).
The courses can also be combined with a prequel course such as Recreational Trimix Diver (IANTD), Discover Tec (PADI) and Intro to Tec (TDI), or further education courses: Technical Nitrox (IANTD), Tec 45 (PADI) and TDI’s Decompression Procedures/Helitrox.

IANTD students have the potential to skip deep air courses completely in their technical range. From the outset a tec candidate can learn to use trimix in the Tek Lite course Advanced Recreational Trimix Diver (48m max depth with O2 blends between 21 and 40%).
Introducing helium theory on top of physics, physiology, gas-blending and oxygen safeguards is pretty hardcore, but the skills circuit is the same as in Advanced Nitrox. Christian Heylen believes that “gases that help to control narcosis levels also help to have divers working with a clear and more focused mind – and this of course makes a difference in training itself”.
With TDI you can enter the realm of trimix at Step 2 – Helitrox instead of Decompression Procedures (min O2 21%, max HE 20%). With PADI, unless you take a distinctive speciality course you can use trimix on the final dive of the Tec 50 course (Step 3, as long as your instructor can teach trimix), or Tec 65 level (Step 4).
Helium isn’t about to get any cheaper, but for the student diving in cold water or for whom money is no object, it makes sense to introduce it at an early level.
If instructors have done their job properly, their little Padawans will have fallen head-over-heels in love with twin-set diving and will either go the whole way into deep open-circuit training or cross over to CCR units in good time.

You’ve completed the course – what now? How do you know if you received good instruction? How can you practise and keep your skills fresh? Which diving destinations and wreck sites can you visit? When can you complete the next step?
All three agencies have some form of post-course questionnaire to ensure that instructors are following standards and procedures properly. IANTD’s, required at the end of every training programme, are signed in conjunction with the Watermanship skills completion form.
PADI’s Course Evaluation Questionnaire is sent to every student. If a negative response is received, Vikki Batten says that the concerns “are investigated in a fair and consistent manner through PADI’s Quality Management process”.
Mark Powell believes that “any instructor who does not provide the high quality of instruction that is expected of a TDI instructor is not just damaging their own reputation but is also damaging the reputation of the agency and all other TDI instructors. As such the TDI QA process is a way of ensuring that TDI instruction is always of the highest quality.”
Christian Heylen says that keeping the attention of newly qualified students is very important to IANTD. “If the local diving facility or instructor doesn’t offer diving activities related to the level the diver has achieved to participate in, the diver will stop practising or evolving because of lack of opportunity.” The agency also organises exploration dives and expeditions, “keeping interest high.”
PADI says it has training consultants on-hand to answer questions either by phone or on the “Ask the Experts” section of its website. There is also a regular newsletter, TecRec blogs, emails, webinars, dive shows and an “On the Road” schedule for meeting staff.
TDI students receive an account on the website and can access more information. They also receive a monthly newsletter with “articles designed to encourage them to maintain their skill levels and inspire them to continue their tech diving”. Mark Powell also personally offers free refresher courses, provided he has available spaces and runs trips.
Most UK dive-centres offer PADI and TDI entry-level tec as a “three-day” course. This usually includes an evening of theory, an evening in confined water and two days at an inland site to complete the open-water dives. Prices range from £295-400.
IANTD courses generally take four days, with prices up to £500. Many UK centres charge extra for equipment rental if twin tanks are chosen, and gases can also attract an extra charge, so read the small print. Accommodation is extra should you need to board close to the training site.
Red Sea courses tend to include the kit as standard. Websites mostly recommend that students read manuals before arrival, but still sell the courses as three days. They charge 320-385 euros. IANTD courses are advertised in some centres as four days, so can be slightly more expensive.
Many websites in Malta say that they could take “2-3 days” to teach the PADI Tec 40 course and so are slightly cheaper at 245-270 euros. I strongly recommend reading the manual and completing the knowledge reviews if you attempt a two-day course using twin-set configuration.
TDI and IANTD’s are advertised mainly as three-day courses, priced around 335 and 475 euros respectively.

All these courses have been written by highly experienced divers with impressive backgrounds, but ultimately the way you receive your chosen training is down to your instructor. Every instructor should have gone through rigorous training to get to this level and – I would hope – have carried out a wealth of technical dives.
The quality of teaching should be exemplary so do your research, ask the dive-centre and agency staff questions and don’t be afraid to tell your instructor if you aren’t happy with your performance.
No mentor should persecute you for wanting more time to rig your gear, repeat drills or practise calculations.
In addition, heed their advice – even if it is about your level of fitness (no instructor wants an accident on his or her hands).
A good teacher will push your comfort zone while simultaneously nurturing you through emergency drills that produce efficient muscle memory and highly skilled new technical divers, who can safely plan and execute deeper dives.
I leave you with the wise words of Mark Powell: “Tec training has moved from being a completely different branch of diving, shunned by the mainstream diving industry, into a much more popular and accessible aspect of diving.
“This could be a very positive aspect for tec diving, provided that we can maintain the same safety standards.”

IANTD: www. iantd.uk.com
PADI: www.padi.com/scuba-diving
TDI: www. tdisdi.com