CHAPTER 15 Saturation Diving
is activated, all divers shall immediately go on BIBS. Watchstanders should
monitor depth carefully because an extensive fire will cause an increase in depth.
If the fire suppression system fails to extinguish the fire, rapid compression of the
chamber with helium may extinguish the fire, in that helium lowers the oxygen
concentration and promotes heat transfer. After the fire is extinguished, chamber
atmosphere contaminant emergency procedures shall be followed.
PTC Emergencies. PTC emergencies, like DDC emergencies, require specific,
timely, and uniform responses in order to prevent injury or casualty to divers,
watchstanders, and equipment.
Saturation decompression may be initiated by an upward excursion as long as the
excursion remains within the limits permitted by the Unlimited Duration Excur-
sion Tables. The alternative is to begin travel at the appropriate decompression
rate without the upward excursion. Decompression travel rates are found on Table
Upward Excursion Depth. The minimum depth to which the upward excursion
may be made is found by entering Table 15-8 with the deepest depth attained by
any diver in the preceding 48 hours. The total upward excursion actually chosen is
determined by the Diving Officer and Master Diver, and approved by the
Commanding Officer, taking into consideration environmental factors, the divers
workload, and the divers physical condition.
Travel Rate. The travel rate for the upward excursion is 2 fsw/min. Beginning
decompression with an upward excursion will save considerable time and may be
used whenever practical.
Post-Excursion Hold. Due to the increased risk of decompression sickness
following an upward excursion for dives with a storage depth of 200 fsw or less, a
2-hour post-excursion hold should be utilized. The 2-hour hold begins upon arrival
at upward excursion depth.
Rest Stops. During decompression, traveling stops for a total of 8 hours out of
every 24 hours. The 8 hours should be divided into at least two periods known as
Table 15-9. Saturation Decompression Rates.
1,600 200 fsw
6 feet per hour
200 100 fsw
5 feet per hour
100 50 fsw
4 feet per hour
50 0 fsw
3 feet per hour