April 1, 2007
Ten Thousand Hours: Lessons from the Healy CG Vessel Dive Tragedy
by Carl Gwinn, publisher of BlackCormorant.net
Ten thousand hours of "deliberate practice" will produce excellence in any field. According to K. Anders Ericsson, a psychologist, and more recent workers, this figure is the same for almost any field: classical piano, rocket science, bowling. For nearly all divers, ten thousand hours of bottom time is unattainable. We will spend our lives as beginners.
The tragic deaths of ice divers from the US Coast Guard vessel Healey make that point again. If we can learn from other's experiences, perhaps we can gain some of the expertise those 10,00 hours would give us.
For those unfamiliar with the story, this icebreaker set out for the Arctic with half its complement of divers, and dive gear with an undocumented, but probably poor, service history. During a recreational "ice liberty," the divers received permission to try an ice dive to 20 feet, and recruited line tenders from bystanders to fill in for the missing half of their team. Apparently influenced by experience with surface-supplied-air, the divers carried more than 60 lbs of weight each (much of it stuffed into inaccessible pockets) and did not connect LP hoses to their BCs; they relied upon their drysuits for buoyancy. Gear problems delayed the dive and left the divers chilled even before they dropped into the 29F water. The line tenders may have misunderstood their tugs on the lines, and let out nearly 200 feet. When brought back to the surface both divers were dead. The full Coast Guard report on the incident is on the internet (PDF). Every diver can benefit from reading this report.
The investigations following this tragedy have led to recommendations by the government agencies that employ divers. The 13 recommendations of NOAA's Dive Safety Board appear in the March 2007 Topside Newsletter, soon to be online here. As I read them, the NOAA recommendations fall into several broad categories:
- Dives in tricky environments (blue-water, line-tended, overhead or confined-space, and cold-water) require careful planning and, for now, permission from the NOAA Dive Center (NDC). More formal standards are to be announced shortly.
- Diving in these conditions, or with a drysuit, requires proper gear. When wearing a drysuit, divers must use BCs. (NOAA plans to move to the DUI weighting system for drysuits, and the new Oceanic regulator for <50F). Split fins are prohibited in strong currents, with heavy loads or when wearing a drysuit; although split fins do well in Rodale's pool tests (and I love mine with my wetsuit), apparently split fins can stall out when used strenuously. Use of more than 16 lbs in an integrated-weight BC is prohibited; I'm not sure whether they distinguish ditchable from un-ditchable weights here.
- Dive gear must be maintained: this now includes periodic inspections by NDC.
- A topside person capable of rendering assistance must be on site for every dive. Vessels with dive teams are to have full complements.
- Divers are to dive enough to keep their experience current.
These recommendations have clear applications to individual sport or scientific divers. I would summarize them:
- If you dive in an unfamiliar environment or under tricky conditions, be cautious, and be ready to abort for any reason. "One hand at a time in Pandora's Box."
- Likewise, choose the appropriate gear, especially for challenging dives. As my mother told me, "Make sure to get a good regulator: someday your life might depend on it!" Uh, right, I might have to use it to breathe.
- Maintain your gear.
- Make sure that someone else can assist you. This is something to think about: is it really worth it to do that solo night dive without a light?
- Dive lots. Up-to-date skills keep us safe.
Posted by Dida at April 1, 2007 7:35 PM
