I haven't read the whole report yet, but have printed it out, and will be doing so in the next few days. I do already have some observations about this series of dives.
Apparently, there were no experienced divers in the water. All these divers had very little experience, especially in cold water.
The equipment was not suitable for these dives. LT Hill was in a dry suit that was too large for her. The BCs were used inappropriately for weighting. It is interesting that the accident investigation discusses the appropriateness of split fins, saying that they "are not considered appropriate for heavy diving and lack the power necessary to overcome the drag of a drysuit. Instead, they are better suited for light diving and snorkeling..." The did not have redundant breathing supplies, instead relying upon octopus regulators in extremely cold water.
The only qualified dive supervisor was in the water diving; these two duties can not be done concurrently. There was no dive log, the US Navy Dive Manual was not there either, and some of the crew had been drinking (including tenders) during the Ice Liberty.
When "Diver 3" had to abort the dive because of a leaky dry suit, the whole series of dives should have been terminated. There was no standby diver, and Diver 3 got out of his suit completely. Further, when BM2 Duque had problems with cold hands, the dive should have been terminated.
I find it interesting that they were using FFM, that the air in BM Duque's tank was completely depleted, and that LT Hill's tank had only 90 psig in it. The air tested good. There was no CO, ethanol, or screened drug in either diver's systems.
While these findings of fact are interesting, I don't think they pinpoint the exact cause of these two fatalities. A thorough "Fault Tree Analyses" would be appropriate for this event, which is a Systems Safety methodology of looking at an accident scenario. I may do this a bit later, and post some of it here. But one observation is that with a FFM, divers rarely die of anoxia using air with scuba. Something had to cause them to loose their air supply.
Since this is the ScubaBoard, I have to ask if anyone has experience with AGA Full Face Mask a few questions. I find it curious that these divers were very quickly out-of-air at depth, probably because they had been working extremely hard trying to swim to the surface while greatly overweighted, and in extremely cold (29 degrees F) water. I know that the AGA mask has a positive pressure breathing feature on it too (or at least used to in the 1990s). My question to those familiar with the mask (I've only used it a few times, and in a pool) is this, under extreme workload, with high demand for air in extremely cold water, is the AGA FFM prone to icing-caused free flow? If so, and that happened in a positive pressure mode, how long would it take to drain a 100 cubic foot tank, assuming a break in the seal around the face, at a depth of greater than 150 fsw?
John C. Ratliff (SeaRat),
CSP
