Heeding customer feedback and finally bowing to market pressures, PADI’s DSAT technical diving arm is preparing an overhaul of its TecRec Deep and Trimix courses that will lower the entry barriers to the course and give instructors more flexibility.

Although final course outlines have not been finalized, the Tec Deep course will be broken into three parts, tentatively called “Tec 40,” “Tec 45″ and “Tec 50,” signifying the depth in meters students will be certified to dive. The current Tec Trimix course will be similarly broken into two parts, dubbed “Trimix 65″ and “Trimix 75.” DSAT hopes to introduce the courses by the end of the year.

Speaking at DSAT’s forum in Pattaya, Thailand June 21, PADI Instructor Examiner and TecRec Instructor Trainer George Wegmann stressed that the final look of the revamped TecRec program has not been finalized, but that DSAT now had a “strong direction” for 2009. The organization formed the basis for the tiered technical program from feedback at previous DSAT roundtables in Australia and the U.S. While still soliciting input from PADI professionals, the agency is now traveling around the world with its “Essential Change ‘09″ presentation…..Continued

The objective of this course is to train the divers in the benefits, hazards and proper procedures for utilising EAN 21 through to 100 percent oxygen for dives not requiring staged decompression To a depth of 40 msw.

Brian Wilcox, a computer programmer from Oregon, US joined us recently for an Advanced Nitrox Course to acomplish 2 goals. Get certified in the use of basic technical diving gear and also get certified to 40 while allowed to use multiple amounts of nitrox. This was a great alternative to about 4 different PADI courses to get the same result.

This course allowed brian to get into the mix quickly and combine it with his decompression procedures course that he decided to join shortly after. With over 100 logged dives and many years of diving experience Brian adapted to technical diving very quickly and excelled through not only the academic aspects of the course but also the in water differences.

Below are some pictures from his course, accompanied by Cory Lewis and Christos Kardana who have opted to complete their Extended Range course after being certified as DSAT Tec Deep but missed some foundation skills. The extended range course gives them an additional 5m and much different skills.

Though technical training standards have been well established by the American Nitrox Divers, Inc. (ANDI), International Association of Nitrox & Technical Divers (IANTD), Professional Scuba Association (PSA), Technical Diving International (TDI), and Professional Association of Diving Instructors (PADI) and are continuing to evolve. There is currently no set of agreed upon operational guidelines, i.e. guidelines used to direct diving operations, similar to those developed by the professional and commercial diving communities.

Originally presented in aquaCORPS Journal N6/Computing (93JUN), the guidelines which were compiled by technical diving pioneer Capt. Billy Deans/Key West Diver and dive technologist Michael Menduno with the help of many individuals throughout the community in response to the number of technical-level accidents that were occurring during that period. They are based on what are perceived as the best practices from the technical diving community drawing heavily on accident analysis techniques developed by the cave diving community, and were offered as a starting point for the development of “community consensus” guidelines for technical divers.

Now several years later, in light of the tremendous growth in technical diving, and with the majority of the recreational training agencies accepting enriched air Nitrox we felt it was necessary to update and republish these critical guidelines. Many people’s comments and suggestions for the development of these guidelines have been incorporated in this document.

Background
About twenty years ago in response to the then growing number of fatalities, the cave diving community developed a set of safety principles based on the then-new tool of accident analysis. Later refined by pioneer Sheck Exley and elucidated in his book Basic Cave Diving: A Blueprint for Survival (Exley, 1979, 1986), accident analysis is a means to rigorously dissect an accident into its constituent parts with the goal of determining what went wrong. Applying this tool to cave diving, it was discovered that most diving accidents could usually be attributed to a primary causal factor and typically one or more contributing factors. What’s more is that these factors could be boiled down into five basic cave diving safety principles: be trained, use a continuous guideline to the surface, manage your gas according to a thirds rule or better, don’t dive deep (on air), and carry at least three lights. A sixth principle, known as Eternal Vigilance, states: Anyone Can Die At Any Time On Any Cave Dive. Accident analysis of these resulting safety procedures have become the cornerstone of cave diving safety ever since.

Numerous other analysis of sport diving accidents have been conducted following the early cave diving work. In 1989, Mano and Shibayama published a study titled Aspects of Recent Scuba Diving Accidents (Mano and Shibayama, 1989), which analyzed 264 fatalities and 319 incidents of decompression illness and arterial gas embolism. According to the authors, over 45% of sport diving fatalities that occurred were due to reckless diving or lack of technique. Most appear to have been preventable. In another study, Chowdhury, in affiliation with the National Underwater Data Center (Chowdhury, 1989) conducted an analysis of wreck diving accidents. His conclusions were that 73% of the accidents involving wreck penetration were due to the lack of a continuous guideline, while 42% of the fatalities that occurred external to a wreck were due to out of gas emergencies.

In 1990, the late Sheck Exley revisited his earlier work in a paper published in Underwater Speleology. Based on the recent trends in accidents, Exley concluded that perhaps too much emphasis was being placed on the basic cave diving principles in light of more recent tools and techniques being employed by cave divers (e.g., mix technology), and that an expanded list of safety recommendations should be developed.

Exley’s conclusions provided motivation for the original paper. Our approach was to attempt to identify and address the factors that could potentially result in diver injury or death, building on the cave diving safety principles and practices from the community. The resulting guidelines are organized into seven categories: Requirements, Training, Gas Supply, Gas Mix, Decompression, Equipment, and Operations.

Requirements
The generalized requirements for conducting technical dives were aptly summarized in the form of the acronym AKTEE.

These are:

Attitude:
Why are you doing this? A proper attitude is essential to conducting technical dives safely. There is no room for recklessness or machismo.

Knowledge:
Without the proper knowledge, there are no options when problems occur.

Equipment:
Every dive requires an appropriate set of tools.

Training:
Skills must become second natural part of muscle memory.

Experience:
Experience is exposure and environmental specific and takes time to build. Extensive wreck diving experience does not qualify a diver for cave diving and visa versa.

Note that the more challenging the dive and the further the dive goes beyond mainstream sport diving limits, the more risk the diver must accept. No amount of training or equipment will completely mitigate this risk.

Training
Technical training is an ongoing process similar to training for an athletic season or fight training. Continual practice is the key. Completing a formal course is a good first step, but is only a starting point. It does not in itself prepare you to make the dive. Technical diving is a discipline and a “mind-set” it’s not just a card.

1. Always be prepared and trained for the dive you plan to conduct. Perform a risk assessment. Ask yourself if you, and your partner, meet the AKTEE criteria and if the dive is worth the risks involved. If the answer is no to either question, call the dive.

2. Review and practice emergency procedures frequently so that they become second nature.

Gas Supply
Ensuring adequate gas supply is the major constraint factor in self-contained diving and represents the single largest risk factor. In particular, planning and carrying adequate gas reserves is critical.

3. Always dive an appropriately redundant breathing system (minimally first and second stage redundancy) in an overhead environment, or when diving in open water beyond 130 f/ 40 m. Second stage redundancy and a dive partner is an acceptable redundant system in open water no-stop diving (recreational diving) to 130 f/40 m in good conditions though an independent redundant system is recommended for dives deeper than 60 f/18 m and/or in less than ideal conditions.

4. Pre-plan and calculate the gas required to conduct the dive (Gas requirements = planned consumption plus required reserves) and dive your plan. Gas calculations should be based on the most conservative breathing rates of you and your partner. Always dive your bottom gas using at least the Rule of Thirds [Turn the dive when one third of your gas is exhausted, leaving two thirds for the exit and reserve] in an overhead environment, or a suitable equivalent in open water, depending on the operation. There should be sufficient reserves for the dive team to exist safely in the event one diver suffers a catastrophic gas loss. For extended open water dives, the consensus seems to be to reach your first decompression stop with one third of your bottom gas remaining.

5. Plan at least a 33% reserve (1.5 x planned usage) for your decompression gas. Depending on the operation, decompression cylinders should be equipped with redundant regulators.

6. When possible, carry all the gas you will need for the dive unless it can be reliably staged, depending on the operation and environment. Note that the ability to reliably stage gas is one of the major differences between cave and wreck diving. In open water diving the goal is to be self-sufficient, to the maximum extent possible. Based on an analysis of gas logistics, the self-sufficiency breakeven point for extended open water dives appears to be about 250-300 f/77-92 m for a two-person team, depending on the duration of the dive. Open water dives beyond this require an extensive support team and effective communications.

Gas Mix
Mix technology is a tool designed to improve underwater safety and performance when properly applied. The most critical factor in special mix diving is oxygen management due to the risk of a CNS toxicity convulsion.

7. Always dive the safest possible mix(es) for the dive you plan to conduct.

8. Always analyze and label your gas and regulators before making the dive. Make sure that you know what you are breathing. Use a contents tag that specifies the type of gas and maximum operating depth. Any cylinder or regulator carrying a potentially hyperoxic gas (PO2=1.6+ at any depth during the dive) should also ideally have touch ID capability for zero visibility conditions (see below).

9. Maintain your PO2s at or below 1.45 atm during the working phase of the dive and anytime more than light work is being done, boosting oxygen levels to a maximum of 1.6 atm with care, during resting decompression. The community standard today is to run travel and bottom mix at about 1.2-1.45 atm, depending on conditions and the operation and PO2s of 1.4 -1.6 atm are generally treated as a caution zone. Take regular air breaks, as a safety hedge every 20-25 minutes when breathing oxygen. If air is not available, the lowest FO2 travel gas should be used. Some trainers take breaks during the decompression phase of the dive whenever the CNS index exceeds 80%. Note that the CNS indices being used today are just guidelines and are not necessarily supported by hard data. As succinctly summarized by Terry Billingsley (Hamilton, 1985): CNS toxicity is like sand beside the road. If you stay on the road, you won’t get into trouble.

10. Just Say No to nitrox mixes ( like air) beyond about 180-200 f/55-61 m or less, depending on the operation and environment. In particular, keep equivalent narcotic depths (END) as shallow as operationally and economically feasible, preferably 150 f/46 m or less. Note that ANDI limit s nitrox (air and EAN) exposures to 165 f/ 50 m. PSA allow s very short non-working exposures to 240 f/ 72 m and deeper under the supervision of two instructors per student.

Decompression
Decompression illness is not an accident. It happens and will continue to happen as a predictable part of diving.

11. Always use appropriate and reliable decompression methods and tools for the dive you’re planning to conduct and be conservative. Carry bailout tables for gas loss scenarios.

12. Utilize a hyperoxic mix for decompression (e.g., oxygen and/or suitable EAN mixes) whenever possible when conducting a staged decompression exposure. Oxygen at 10 and 20 f/3 and 6 m stop is preferred in some circles [Air, and to a lesser extent EAN mixes, have been regarded as inefficient at reducing decompression risk (Vann, 1992)], though EAN 80 (80% O2, 20% N2) has grown in popularity as it is thought to reduce CNS toxicity risk and can be used at 30 f/ 9 m. Note just as it is recommended that divers make a safety stop on no-stop dives, some individuals prefer to treat the first (deepest) stop on a mix dive in the same manner and make a couple minute safety stop at least 10 f/3 m deeper than required.

13. Limit oxygen decompression to 20 f/6 m or less (max. PO2=1.6 atm) and use care. The diver breathing a decompression mix or oxygen should avoid anything that would increase the likelihood of CNS oxygen toxicity, or specifically, anything that might raise the diver’s C02 level. Use an oxygen regulator guard to prevent the accidental use of pure oxygen at depth. Color coding and labeling are insufficient safeguards.

14. Plan for and always be prepared to deal with decompression illness (DCI). In particular, have plenty of oxygen immediately available for treatment after any diving operation and know how to use it. Many people believe that low-cost portable on-site chambers will eventually become the order of the day.

Equipment
Your equipment is your life support system which allows you to survive in a physiologically hostile environment. Second only to breathing equipment in importance, safety lines and a decompression line system are critical to diver safety.

15. Always use the best possible equipment that is well-maintained and appropriate for the dive you plan to conduct and the environment. Redundancy on all essential subsystems is key. In particular, always carry appropriate emergency equipment and know how to use it, for example: three lights (overhead environment), a decompression reel and lift bags (open water) surface signaling device (open water) and a bail-out bottle when diving as a team of one.

16. Always use a continuous guideline when diving in an overhead environment, and/or a decompression line system when conducting extended and/or deep open water dives. Note that conducting multi-level extended range open water hangs without a safety line home can be problematic and difficult. They require skills and practice to perform without compromising effective decompression, particularly when using hyperoxic decompression mixes where depth control is critical.

Note that the original set of guidelines (1993) included the following point; If possible, wear breathing equipment that allows you to survive an underwater convulsion/loss of consciousness, such as a full face mask system or retaining strap. The use of full face masks is growing and will likely become a standard for many technical diving applications due to their many advantages.

In practice this point has not stood up in the field. Technical divers have not embraced full face mask technology, nor have FFMs become a standard. This may change when rebreathers finally hit the market and/or when an effective mask is developed for technical diving applications. In the meantime practice the effective and conservative use of oxygen management in order to avoid a CNS hit.

Operations
Technical dives are operations: a project or venture involving planning, preparation, organizational structure, the use of proper equipment, teamwork, competent execution, and the capacity to respond to emergencies effectively and immediately. Diver safety is always the first priority. In terms of support requirements, technical dives fall somewhere in between recreational dives and commercial operations. Note that all dives are operations. In the case of traditional *recreational diving, the requirements are minimal.

17. Pre-plan all aspects of the dive you intend to conduct and dive your plan. Design your operation with the goal of being able to provide effective and immediate assistance to a diver in distress at any point in the dive. In particularly be prepared for the worst, and always have plenty of oxygen on hand and know how to use it. Above all, if you’re not prepared to do it right, don’t do it.

18. Always dive as a team, using surface support personnel, and when appropriate, in-water support divers, whenever possible. In particular, designate an operations manager, who is responsible for overseeing diver safety and record keeping. Note that the buddy system is not reliable enough for technical diving. A team approach based on individual self-sufficiency and competency is required, though an team of one is acceptable in some circumstances, depending on the operation and environment. Above all, always honor rule number one of team diving: anyone can “call” the dive at any time for any reason (anyone can die just as easily).

19. Utilize an effective communications system between the dive and support team whenever possible. In the future, wireless communications systems will likely become commonplace.

20. Stay within your “comfort zone” during all phases of the dive.

21. Remember: YOU, and YOU ALONE, are responsible for your own safety. Never permit overconfidence or peer pressure to allow you to rationalize compromising safety procedures. It could ruin your whole day.#

*Definition:
Technical diving is a discipline that uses special methods and equipment to improve diver safety and performance enabling the user to conduct dives in environments and perform tasks beyond the scope of traditional recreational diving i.e. no-stop dives in an open-water environment to 130 f/40, Europe limited decompression dives to 50 m/165 f.

For more information about technical diving, contact us at info@bigbluetech.net

Yesterday’s Sail Rock trip was a great success for Big Blue Tech. On top of the technical diving training we provided 14 nitrox tanks to customers from our new nitrox panel.

The day started at 6:30 with loading of gear, customers, food, drinks, nitrox and staff. After both long tails trugged out to one of our boats - Navakid - we began the almost 2 hour journey to Sail Rock. Normally this journey can be quite long and boring, however for us it was broken up with breakfast. Scrambled eggs, toast and jam served to the 30 divers.

Sail rock is a unique dive site and perfect for technical extended range diving because the dive site is extended above the surface and shaped like a cylinder. There’s unique marine life at 2m and 40m. Sail rock is mostly used for dive schools from closer islands like Pangan and Samui, only few schools from Koh Tao venture that far out.

For us, we had quite a long dive planned. This was training dive 6 for Hannah where she completed a simulated extended range dive, switching gas and moving shallower to extend her no decompression limit. The conditions were stunning, large schools of every fish throughout the dive site. From our max depth of 30m we could see clearly right down to 40-45m which was very tempting but not for today. With all skills completed and a great long dive we surfaced, filled gas, socialized with others on the boat and prepared for the real extended range dive.

For real extended range dive you must get on to your richer mix in time or you will go in to decompression diving. Albeit not a concern for us but it defeats the purpose of this dive. Here Hannah was able to switch in time and also practice her tolerance for long decompression hands on the simulated 30 minute decompression stop. One of the hardest things to instill in people is the idea that you can’t just go to the surface whenever you want.

Upon surfacing Hannah had completed dives 6 and 7 and was technically eligible to be certified as a Dsat Tec Apprentice. However she’s not stopping there, she’s moving on to Accelerated Decompression in the next few days and then on to the Trident Livaboard on the 23rd so there’s still much more training to be completed.

Our final dive site of the day was South West Pinnacle, cleverly named after the direction from Koh Tao. To all our amazement there was no thermocline to be found. The water was so clear you could see the light refraction from the surface dancing along the sand at 30m, normally you only see this effect in shallow water like a pool or a bay. This was just a fun dive. We used the rest of the nitrox to do a computer extended range dive without any skills to just give Hannah more time in technical gear and because it was better then sitting on the boat. The next training dives are accelerated decompression which require oxygen and they are more risky so we won’t be doing that until a wreck Wednesday dive.

Today unfortunately we’ll be in the hot sweaty compressor room filling the tanks from yesterday and prepping for the DSAT Gas Blender Course tomorrow as Hannah takes some time off to study for her next exam.

Today Big Blue Tech will be boarding the Mv Trident for 4 Days of technical wreck exploration and training. BBT will be joined by other members of the Koh Tao community and rebreather divers from Pucket and Australia.

The plan for the trip is a 3 day stint at HTMS Pangan and an additional day exploration.

From BBT will be James “Canada” Thornton-Allan, Niall Mackenzie as the main instructors; Ben, Marco and Shoko who are completing their DSAT Tec Deep course and Matt Rolph as medic support (he’s bringing his fancy satellite phone too)

This day has come together from a combined effort to train Ben, Marco and Shoko to a level where they can complete deep ocean decompression dives using oxygen and nitrox to accelerate their time.

During this time we’ll be out of reach. Feel free to email us and we’ll get back to you on our return.

Today is the graduation for a newly certified technical extended range diver. Over the past few days we’ve been working together to create a technical diver. This is a long and difficult process but well worth the reward in the end. Ben had excelled in all the skills and learned the fine art of technical diving early on.

Ben loved the course so much he’s decided to continue his education and join us on the HTMS Pangan trip in august completing his Accelerated Decompression course the handling of pure oxygen. If you have been following our news, Ben was hooked on deeper longer diving after completing his Deep and Nitrox course.

Check out the gallery of images from his course below.

The concept and term ‘technical diving’ are both relatively recent advents, although divers have been engaging in what is now commonly referred to as technical diving for decades. There is some level of professional disagreement as to what the term should encompass. Broadly, technical diving is any type of SCUBA that is considered higher risk that conventional recreational diving. However, some advocate that this should include penetration diving (as opposed to open-water diving, whereas others contend that pentrating overhead environments should be regarded as a separate type of diving. Others seek to define technical diving solely be reference to the use of decompression. Certain minority views contend that certain non-specific higher risk factors should cause diving to technical diving. Even those who agree on the broad definitions of technical diving may disagre on the precise boundaries between technical and recreational diving.

Depth

Technical dives may be defined as being either dives to depths deeper than 130 feet / 40 meters or dives in an overhead environment with no direct access to the surface or natural light. Such environments may include fresh and saltwater caves and the interior of shipwrecks. In many cases, technical dives also include planned decompression carried out over a number of stages during a controlled ascent to the surface at the end of the dive.

The depth-based definition is derived from the fact that breathing regular air while experiencing pressures causes a progressively increasing amount of impairment due to nitrogen narcosis that normally becomes serious at depths of 100 feet / 30 metres or greater. Increasing pressure at depth also increases the risk of oxygen toxicity based on the partial pressure of oxygen in the breathing mixture. For this reason technical diving often includes the use of breathing mixtures other than air.

These factors increase the level of risk and training required for technical diving far beyond that required for recreational diving. This is a fairly conservative definition of technical diving.

Inability to ascend directly

Technical dives may alternatively be defined as dives where the diver cannot safely ascend directly to the surface either due to a mandatory decompression stop or a physical ceiling. This form of diving implies a much larger reliance on redundant equipment and training since the diver must stay underwater until it is safe to ascend or the diver has left the overhead environment.

Decompression stops

A diver at the end of a long or deep dive may need to do decompression stops to avoid decompression sickness, also known as the “bends”. Metabolically inert gases in the diver’s breathing gas, such as nitrogen and helium, are absorbed into body tissues when breathed under high pressure during the deep phase of the dive. These dissolved gases must slowly be released from body tissues by pausing or “doing stops” at various depths during the ascent to the surface. In recent years most technical divers have greatly increased the depth of the first stops, so as to reduce the risk of bubble formation before the [more traditional] long shallow stops. Most technical divers breathe enriched oxygen breathing gas mixtures such as nitrox during the beginning and ending portion of the dive. To avoid Nitrogen narcosis while at maximum depth it is common to use trimix which adds a percentage of helium replacing nitrogen to the diver’s breathing mixture. Pure oxygen is then used during shallow decompression stops to reduce the time needed by the diver to effectively rid themselves most of remaining excess inert gas in their body tissues and reducing the risk of “the bends.” Surface intervals are usually required to prevent the residual nitrogen from building up to dangerous levels on subsequent dives.

Physical ceiling

These types of overhead diving can prevent the diver surfacing directly:

* Cave diving - diving into a cave system.
* Deep diving - diving into greater depths.
* Ice diving - diving under ice.
* Wreck diving - diving inside a shipwreck.

Extremely Limited Visibility

Technical dives in waters where the diver’s vision is severely impeded by low-light conditions, caused by silt or depth, require an elevated level of aptitude because of the knowledge and skill required to operate in such an environment, and because visibility impairments are often caused by moving water currents. The combination of low visibility and swift current make these technical dives extremely risky to all but the most skilled and well-equipped divers.[citation needed]

Gas mixes

Technical dives may also be defined by the use of breathing gas mixtures other than air such as trimix, heliox, and heliair. This definition is derived from the fact that breathing a mixture with the same oxygen concentration as is found in air (roughly 21%) at depths greater than 180 feet / 55 meters results in a very rapidly increasing risk of severe symptoms of oxygen toxicity. The first sign of oxygen toxicity is usually a convulsion without warning. This convulsion usually results in a fatal accident, as the regulator falls out and the victim drowns. Sometimes the victim may get warning symptoms prior to the convulsion. These can include visual and auditory hallucinations, nausea, twitching (especially in the face and hands), irritibility and mood swings and dizziness. Increasing pressure due to depth also causes nitrogen to become narcotic, resulting in a reduced ability to react or think clearly (see Nitrogen narcosis). By adding helium to the breathing mix, divers can reduce these effects, as helium does not have the same narcotic properties at depth. These gas mixes can also lower the level of oxygen in the mix to reduce the danger of oxygen toxicity. Once the oxygen is reduced below 18% the mix is known as a hypoxic mix as it doesn’t contain enough oxygen to be used safely at the surface.

Nitrox is another common gas mix, and while it is not used for deep diving, it decreases the build up of nitrogen within the diver’s body by increasing the percentage of oxygen. This reduces the nitrogen percentage, as well as allowing for a greater number of multiple dives vs “standard” air. The depth limit of Nitrox is governed by the percentage of oxygen used, as there are multiple oxygen percentages available in nitrox. Further training and knowledge is required in order to safely use and understand the effects of these gases on the body in a diving situation.

Equipment

Technical divers may also use various forms of less common diving equipment to accomplish their goals. Typically technical dives involve significantly longer durations than average recreational scuba dives. As decompression stops act as a virtual overhead, preventing a diver with a problem from surfacing immediately, there is a need for redundant equipment. Technical divers usually carry at least two tanks, each with their own regulator. In the event of a failure, the second tank and regulator acts as a back-up system. Technical divers therefore increase their supply of available breathing gas by either connecting multiple high capacity diving cylinders and/or by using a rebreather. The technical diver may also carry additional cylinders, known as stage bottles, to ensure adequate breathing gas supply for decompression with a reserve for bail out in case of failure of their primary breathing gas.

Technical diving requires specialised equipment and training. There are many technical training organizations: Recent entries into the market include DSAT, the technical arm of PADI.