After the crash of TWA Flight
800 off Long Island, Navy and civilian
divers recovered the aircraft and the
remains of over 100 victims.
Scuba divers made 3,992 nodecompression
dives to an average
depth of 117 feet. Most were planned
within no-decompression limits of
either 120 feet for 15 minutes or 130 feet for 10 minutes, though a few employed
decompression using computers. One third of the dives involved a 3-5
minute safety stop at 20-25 feet.
These dives were particularly stressful because of the long hours, the
hazards (including 67 degree water and 15-foot visibility), and the presence of
human remains. Several divers noted that their hearts were "pounding" in
anticipation of finding the bodies. The remains of over 100 victims were
recovered by divers.
Even so, there were only three cases of DCS, one embolism, and two cases
of vascular headache, which can mimic DCS.
In decompression dives of up to 50 minutes, divers used suits heated with
hot water. Interestingly, 14 of these resulted in five recompression treatments, so
bottom times were reduced and more decompression time was given.
According to a study of the TWA divers, some researchers have come to
suspect that "...the use of hot-water suits is a contributory factor both to the
overall incidence of DCS and to the proportion of Type 2 cases."
So what about taking a hot shower or jumping in the jacuzzi after a dive?
DAN recommends against it. They cite a study published in the Undersea
Biomedical Research Journal in September, 1989, which found a higher incidence
of DCS cases in divers who went from environmentally cold dive conditions into
a hot shower. The test subjects took hot showers approximately 3 hours post-dive
and developed symptoms 30 minutes to an hour after the hot shower. Seventyfive
percent of the test subjects developed pruritus and shoulder pain.
According to DAN, the physiological relationship between hot showers and
DCS is complex. The theoretical supposition is that peripheral blood vessels are
occluded by the gas phase and that the temperature increase causes vascular
dilation and changes the inert gas solubility of the tissues. Of course, DAN
cautions, in the case of divers who go to the resort, take a hot shower, and then
get symptoms, it's hard to say that the hot shower was at fault or that it wouldn't
have happened anyway. But if a diver called and asked whether to take a hot
shower after a dive, DAN says they'd recommend against it.