DAN Technical Diving Conference
Posted By Grant Graves on 14 February 2008
The Divers Alert Network hosted its first technical diving conference on January 18 and 19, 2008. This is the first time a technical diving conference has occurred in the United States since 2003. It is also the first time since the 90s that a neutral party has hosted it. DAN being a safety and science based organization provided for a research rich focus to this conference with a mix of field and expedition reports thrown in.
The conference was limited to 150 people and sold out well before the event. The event brought together some of the giants of the field. This is the first time in over a decade where a sizable portion of the technical community was in the same place at the same time. A very good development.
The two-day program was divided into four sections. The first session was dedicated to physiology. This session had a science focus with presentations on respiration, oxygen toxicity, narcosis and high pressure nervous syndrome, and thermal considerations. General overviews and specific research finding built on the expanding base of knowledge that military, commercial and technical diving has contributed to the understanding of extreme exposure diving. While nothing jumped out as surprisingly new, it is clear that technical diving is becoming an accepted activity within the scientific community and a valued source of data for expanding the understanding of diving.
During Dr. Mitchell’s respiration presentation difficulties with extremely deep diving were presented. Effort independent ventilation seems to be the issue. This is a condition due to gas density and work of breathing where respiration effort will not help move gas in and out of the lungs. Simply, the harder you try to breathe the worse the respirations become. It is a physics issue. The pressure in the chest developed through increased breathing effort can cause gas not to be able to leave the lungs. Evidence of this was presented from a previous fatality. Shows the importance of good breathing training.
Dr. Nuckols’ thermal presentation introduced a new material for insulation that looks very promising. Aerogel is a remarkable material that is added to fabric that is three to four times more insulating than Thinsolate and actually increases its insulation when compressed. This material will be available to the market through Diving Unlimited Internal very soon. It will allow for thinner garments to be worn or better insulation in very cold or long diving applications. The cost will run considerably more than standard garments, but seem to be more than worth the added expense.
The second session was dedicated to decompression. The topics covered were DCS pathophysiology, DCS risk factors, deep stops, DCS therapy, and DCS risk assessment. Again, the focus was heavily science based. Dr. Richard Pyle presented on his use of in water recompression when faced with an injured diver in remote locations. Dr. Pyle was careful to point out the many complicating factors involved in making the decision to consider this therapy.
Deep stops were discussed and what might surprise many is there appears to be evidence that bubble model deep stop profiles may not be better at reducing the risk of incidence of DCS. Although very preliminary, it appears that reduction of decompression time because deep stops are done, may actually make decompression more risky when examined probabilistically. There is not enough evidence to say bubble modeling is unsafe or a bad decompression strategy, but should give some pause to those who use it. Further investigation and an open mind are called for.
The evening included dinner and two presentations. The first was a public safety announcement developed by the HSA from the UK speaking to the risk of carbon dioxide problems while rebreather diving. Based on a real world incident, the piece speaks to proper planning and safety issues related to not planning properly for rebreather diving.
The second presentation was by John Chatterton and Richie Kohler. Never short on sense of humor they began their talk with a spoof called, Brokeback Divers. The title pretty much gives the idea. Following their introduction to too much time in a sub together, they presented dramatic footage of their expedition to the RMS Titanic. Exciting stuff and well worth the wait.
Day two was geared more toward the practical. The morning session covered rebreathers. The presentations covered USN testing perspectives, UK testing perspectives, investigation of rebreather incidents, and then progressed into a manufacturers panel. Devoid of any insights into applications of rebreathers in technical diving, the morning was very heavy into testing of rebreathers and what is important in that effort. The presentations were very interesting dealing with what might be considered important for purchasing a rebreather, but not much was clearly pointed out as to what was more important for diving them.
During the panel discussion most were avoiding controversy and playing nice with each other. What did become clear is that rebreathers are recognized as a growing segment of the technical diving community and clearly seen as something not just for technical divers. From a diving perspective, the rebreather component did not provide much insight into the application of rebreathers in technical diving. It was great for a better understanding of the technical aspects of rebreathers as a piece of life support equipment, however.
The afternoon session was focused on training. The topics included, risk management, risk factors, and concluded with a training panel. John Chatterton and Richie Kohler presented that risk management strategy they employed on their expedition to the HMHS Britannic. Thirteen aspects of their planning were illustrated. They spoke on how they mitigated different divers using different rebreathers and decompression strategies. This was handled by team selection. Divers with the same units and strategy dived together and functioned as a team.
The panel discussion focused more on what delineates technical training versus recreational training as related to rebreathers and open circuit. The panel seemed to become hung up on some of these delineations rather than what is critical to have within a training program or progression. The panel did agree that whether the training is for open circuit or closed circuit it should require a high level of competency and provide for mission orientation. The discussion degenerated into a debate on recreational certification renewal and the state of recreational training. Everyone played nice and a good bit of humor was used to keep it polite.
The evening dinner session concluded the events of the conference. There was a presentation by Kathy Weidig on an oxygen toxicity incident that occurred on the 2004 Silverstein / Weidig USS Monitor Expedition that happened to be caught on video. Following Kathy, Jarrod Jablonski covered the work the WKPP has done that allowed for the traverse from Wakulla to connect with the other cave systems of the area. The longest traverse ever conducted in a cave system with most of the dive happening below 250 feet / 76 meters. The work that has been done is impressive and daunting. The longest dive to date was conducted for twenty-six hours of total run time.
Overall, the conference was a well-attended and run event. Having a place to bring together the technical diving community under one roof has been missing for some time in the US. At least everyone is talking again. Unfortunately, the vast majority of the participants were the same faces that were present at the shows in the mid nineties. Hopefully, future events will provide room for a larger and more diversified audience to attend. Let’s hope that future events will continue. This one was a great start to a new beginning of community building for technical diving.
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