As Rob Neto said, IUCRR information is factual only. Speculation is supposed to be left out. Information like the location and state of the body, the state and location of the equipment, the conditions of the cave, weather, and the victim's age, sex, and experience are recorded. The cave community can take the reported information and compare them against the Rules of Accident Analysis.
PSAI cave training lists 10 Rules of Accident Analysis. The first 5 Rules of Accident Analysis were those that came from Sheck Exley and Wes Skiles which we are all familiar:
1. Be trained for cave diving and don't exceed your level of training
2. Always run a continuous guideline to open water
3. Always reserve at least 2/3 of your gas supply for exit
4. Always carry at least 3 lights
5. Never dive deeper than 130 feet on air or have an END greater than 130 feet on mixed gas
While the first 5 Rules of Accident Analysis have reduced the deaths of untrained cave divers and made cave diving safer, Jeff Bozanic looked at what situations resulted in the most deaths of trained cave divers in recent years. From these 5 additional causes of fatalities PSAI's Accident Analysis 2008 includes:
6. Inappropriate gas mixtures
7. New technology
8. Medical problems
9. Solo diving
10. Poor skill and equipment maintenance
Inappropriate gas mixtures - Cave divers have died due to switching to incorrect deco gases, poorly analyzing or not analyzing deco or bottom mixes, poorly labeled or mislabeled cylinders, improper mixing procedures, closed isolators upon filling, cave divers progressing to stage bottles too quickly, etc.
Rule: Always analyze your gas before diving it. Properly label all cylinders. Follow safe mixing procedures.
New technology - The use of rebreather technology carries a greater risk than open circuit, the use of scooters allows divers to move farther and faster with less experience, and new technologies are available to less experienced cave divers who go "too far too fast." Increased task-loading, combinations of rebreathers and scooters, over-extending abilities on new technology.
Rule: Progress slowly gaining the appropriate experience. Follow manufacturers recommendations for the maintenance of rebreathers, always follow a safety checklist and don't dive any rebreather which is not functioning 100% correctly. Rely upon your abilities and hone those skills on open circuit and perfect swimming techniques before moving to rebreathers, scooters, etc.
Medical problems - As the cave diving population ages known and unknown medical conditions will play a more significant role in diving accidents. Many old cave divers are still active and many new cave divers are older. Undiagnosed conditions and chronic health problems related to blood pressure, arteriosclerosis, and other issues will be present in more cave divers. Poor physical condition due to age, obesity, poor diet and a sedentary lifestyle. Heart attacks, strokes, etc.
Rule: Exercise, maintain a healthy diet, maintain a healthy weight in proportion to height, reduce BMI by reducing stored fat, increase lean muscle, have regular medical check-ups, don't neglect teeth and gums, be cleared for diving, take medicines that won't have an adverse effect on diving, be aware that we have heightened risk for diving injuries and medical emergencies as we age. Follow doctor's recommendations for dealing with chronic medical conditions.
Solo diving - Much new exploratory cave diving is being done solo due to a lack of qualified or courageous dive partners. Sidemount configurations are allowing easy solo diving. Solo divers lack a back-up brain and physical help.
Rule: Be aware that solo cave diving is increasingly more dangerous. Adjust dives accordingly. Cave dive with other capable buddies.
Poor skill and equipment maintenance - In the past, cave divers were cave divers now many cave divers only cave dive on vacations. People return to dives they were once capable of, but now might be beyond their skill level. Complacency with equipment maintenance, poor regulator servicing, exposure suit issues, rebreather issues such as failure to change sensors or over use of absorbent, configuration issues, and too much redundant equipment all contribute to cave diving fatalities.
Rule: Maintain cave diving skills and equipment even when not cave diving. Start off slowly when returning to cave diving and progress. Make sure all equipment is working properly.
If we look at Bill's accident, the three primary possible culprits were solo diving, rebreather technology and medical problems. Had he had a buddy, maybe whatever the reason for the accident could have been better managed. Then, again, maybe not. Every solo diver enters the water knowing that this is a risk and accepts it. Diving with a medical problem increases one's risk, but many of us wouldn't quit diving. My boat captain is a professional paramedic who had a heart attack and returned to trimix diving once his physician cleared him. We probably know many cave divers who are taking medicine for high blood pressure, cholesterol, etc., and others who have returned to the sport after heart attacks, cardiac surgery, stroke rehab, etc. Did the rebreather play a role? Who knows? But, we all know that rebreathers carry a greater risk. Bill knew and accepted the risks. He probably would have rather had the last day of his life be in a cave rather anywhere else.
