Accident Analysis for cave divers began after the Florida legislature came very close to prohibiting diving in caves, springs and sinkholes after 24 fatalities were recorded during the 1974 - 1975 diving season. This was discovered to be related to untrained or improperly trained divers placing themselves in the very dangerous situation of diving in caverns and caves.
Comparing this to open water deep air diving, we'd have to look at the number of fatalities that result from untrained or improperly trained divers pursuing deep air diving activities. How many were trained? How many exceeded the limits of their training, i.e., diving air at the extended range level when they are certified for advanced nitrox and decompression procedures?
In 1977, Sheck Exley published Basic Cave Diving: A Blueprint for Survival in which he listed the known causes for the majority of cave diving accidents. According to Sheck the main reasons that divers died in caves was:
1) Failure to run a continuous guideline to open water
2) Failure to reserve at least 2/3 of the gas supply for exit
3) Diving deep in caves
"Deep" was defined as greater than 130 feet on air.
By 1984, Wes Skiles added:
4) Failure to be trained or exceeding the limits of one's training
5) Failure to carry at least 3 lights
By the 1990's, there was a huge drop in the number of open water divers dying in caves. This was the result of the efforts of the cave diving community to raise awareness of the need for training. The NACD, the NSS-CDS and landowners (both public and private) began to make sure that divers entering caves had the proper certifications and qualifications.
Based upon the cave diving rules for accident analysis, to study the safety margins for deep air diving based upon this blueprint, we would have to determine the role that equipment has played in deep air diving safety. Is something missing? Line and lights are necessary for safe cave diving. What equipment might make deep air diving safer? How many deep air depths were related to lack of proper gas management?
What depth on air is really "deep" to the point that it would contribute to an equal proportion of accidents that cave divers experienced deeper than 130 feet? Is it 130 feet? 150 feet? Deeper? Shallower? Since the cave community has studied cave diving accidents the open water community can either adopt the cave community's standards for safety, study deep diving and wreck diving deaths the same way cave deaths have been studied to create rules of accident analysis for deep diving and wreck diving, or take no action if the number of accidents is considered to be within acceptable numbers of risk and loss.
I would think that if we took any action against deep air training to establish limits of deep air training, it should somehow tie into the accident statistics of deep cave divers exceeding the 130 foot maximum recommended air depth in caves. Caves are different than open water and the complexity of navigating caves when facing narcosis may create a more conservative deep air limit than would be needed by open water divers.
The DIR community has chosen to take the cave diver's saying of, "Every dive is a cave dive," and apply that to all their diving needs whether in caves, in wrecks, or in open water. What must be kept in mind is that the philosophy was spawned based upon cave diving needs and then equally applied to all environments. Is it possible that cave diving limitations and DIR limitations may be too prejudiced against air or advanced nitrox diving in open water? I don't think the diving community has adequately explored deep air diving safety as equipment, training, and personal diving standards have improved. It could very well be that both cave and open water communities should scale back their air depth to 100 feet or less, but it could also go the other way and deep diving accident analysis may extend the range of air dives even deeper than our own fears, prejudices, and mythologies.
By the late 1990's to the present day, the number of trained cave divers dying in caves is increasing. According to Jeff Bozanic who is continuing the study of accident analysis, data on cave fatalities has shown that trained cave divers made up less than 10% of deaths until 1985. By 1995, trained cave divers amounted to nearly 40% of deaths. By 2008, cave divers made up 50% of all cave diving fatalities.
What is causing this?
Jeff Bozanic has added to the Rules of Accident Analysis (2008):
6) Inappropriate gas mixtures or failure to properly analyze gases
7) New technology allows divers to go deeper, farther, sooner in their cave diving careers and some cave divers believe the decreasing standards of recreational diver and recreational instructor training are contributing to lesser divers employing greater technology to dive beyond their physical and mental abilities and experience level (PSAI Cave Diving: Safe and Smart page 141).
8) Medical problems associated with an aging active diving population and a younger diving population that is less physical fit and less healthy
9) Poor equipment care and maintenance
10) Solo diving
11) Poor skill maintenance as many more cave divers are "vacation" cave divers and may not adequately keep up their abilities to do the type of diving they jump right back into when cave diving.
How many of these new rules of cave diving accident analysis can we apply to deep air diving? In the PSAI cave manual, the question is posed, "How deep is too deep?" The answer is that is determined by each individual's training, experience, and comfort zone.
Since the average diver of today is often more poorly trained during recreational diver training, has been less physically challenged as a diver, is less physically fit, and is more reliant upon technology to replace physical adaptation to the environment, deep air training is more likely to be scaled back in modern studies as it would be less safe for today's diver than those divers trained 30 or more years ago.
Added to which, the comfort zone for deep diving has been reduced. The Mount-Milner Survey which tested the psychological - physical relationship of deep air divers discovered that one's mental attitude toward narcosis played a significant role in performance at depth. The average diver of today is more likely to fear narcosis and to allow that fear to decrease performance during air dives.
The "macho" divers of the past relied upon themselves. The also were active, ate real food grown by actual farmers, and had a can-do spirit.
The "smarter" divers of today rely upon information. They are less active, eat genetically manufactured food-like substitutes, and have a can't-do spirit forged by too many legalities and having to trade common sense for computer sense. "I'd love to do that for you, but I can't because the computer won't let me ..."
As deep divers, especially those who still need to utilize air where helium doesn't exist, we need to rethink and reexamine deep diving. What can we learn from the macho generation that will bring back a different less cynical spirit to the sport? What can we learn from the information we have today that will make diving air at depth safer and what can we do with our technology to increase safety? Is trimix, rebreathers, and scooters the only answer or are we missing something?
I think just as the last nail is about to be driven into the coffin of deep air, economics may find the nails being clawed out.
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