14-18 Change A
U.S. Navy Diving ManualVolume 3
even fatal, decompression sickness if the diver is brought to the sur-
face, versus the risk of asphyxiation if the diver remains in the water.
As a general rule, if there is any doubt about the diver's breathing
status, assume he is breathing and continue normal decompression in
the water. If it is absolutely certain that the diver is not breathing, leave
the unaffected diver at his first decompression stop to complete decom-
pression and surface the affected diver at 30 fsw/minute, deploying the
standby diver as required. Recompress the diver immediately and treat
for omitted decompression according to Table 14-2.
Decompression Sickness in the Water. Decompression sickness may develop in
the water during surface supplied diving. This possibility is one of the principal
reasons for limiting dives to 300 fsw and allowing exceptional exposures only
under emergency circumstances. The symptoms of decompression sickness may
be joint pain or more serious manifestations such as numbness, loss of muscular
function, or vertigo.
Management of decompression sickness in the water will be difficult under the
best of circumstances. Only general guidance can be presented here. Management
decisions must be made on site taking into account all known factors. The advice
of a Diving Medical Officer shall be obtained at the earliest possible moment.
Decompression Sickness Deeper than 30 fsw. If symptoms of decompression
sickness occur deeper than 30 fsw, recompress the diver 10 fsw. The diver may
remain on 50% helium 50% oxygen during recompression from 90 to 100 fsw.
Remain at the deeper stop for 1.5 times the stop time called for in the decompres-
sion table. If no stop time is indicated in the table, use the next shallower stop time
to make the calculation. If symptoms resolve or stabilize at an acceptable level,
decompress the diver to the 40 fsw water stop by multiplying each intervening
stop time by 1.5 or more as needed to control the symptoms. Shift to 50% helium
50% oxygen at 90 fsw if the diver is not already on this mixture. Shift to 100
percent oxygen at 40 fsw and complete a 30 minute stop, then surface decompress
and treat on Treatment Table 6. If during this scenario, symptoms worsen to the
point that it is no longer practical for the diver to remain in the water, surface the
diver and follow the guidelines for symptomatic omitted decompression outlined
in Chapter 21 of Volume 5.
Decompression Sickness at 30 fsw and Shallower. If symptoms of decompres-
sion sickness occur at 30 fsw or shallower, remain on oxygen and recompress the
diver 10 fsw. Remain at the deeper stop for 30 minutes. If symptoms resolve,
surface decompress the diver at the end of the 30 minute period and treat on Treat-
ment Table 6. If symptoms do not resolve, but stabilize at an acceptable level,
decompress the diver to the surface on oxygen by multiplying each intervening
stop time by 1.5 or more as needed to control symptoms. Treat on Treatment Table
6 upon reaching the surface. If during this scenario symptoms worsen to the point
that it is no longer practical for the diver to remain in the water, surface the diver
and follow guidelines for symptomatic omitted decompression outlined in Chapter
21 of Volume 5.