Chapter 9 Navy Dive Manual Flashcards
Deepest Depth?
Maximum Depth?
Stage Depth?
The deepest depth recorded on the depth gauge during a dive.
The deepest depth obtained by the diver after correction of the depth gauge reading for error. During SCUBA ops the Divers depth Gauge is considered error free. During surface supplied diving ops the max depth is the deepest reading on the pneumofathometer gauge plus the pneumofathometer correction factor. MD is used to enter decompression tables.
Stage Depth is the pneumofathometer reading taken when the divers are on the stage just prior to leaving the bottom. SD is used to compute the distance and Travel time to the first stop or to the surface if no stops are required.
What is RN?
What’s a repetitive dive?
What is a repetitive group designator?
What is RNT?
RN is the excess nitrogen gas still dissolved in a diver’s tissues after surfacing.
Repetitive dive is an dive conducted while the diver still has come residual nitrogen in his tissues.
Repetitive Group Designator is a letter used to indicate the amount of residual nitrogen remaining in the diver’s body following a previous dive.
Residual nitrogen time is the time that must be added to the bottom time of a repetitive dive to compensate for the nitrogen still in solution in a diver’s tissues from a previous dive. RNT is expressed in minutes.
What are all the Pneumofathometer Correction Factors?
Pneumofathometer Depth
Correction Factor
0-100 fsw = +1 fsw
101-200 fsw = +2 fsw
201-300 fsw. = +4 fsw
301-400 fsw. = +7 fsw
What 6 tables are required to preform the full spectrum of air dives?
Air Decompression Table (Table 9-9)
Residual Nitrogen Time Table for Repetitive Air Dives (Table 9-8)
No-Decompression Limits and Repetitive Group Designation Table for No-Decpmpression Air Dives (Table 9-7)
Required Surface Interval Before Ascent to Altitude After Diving (Table 9-6)
Repetitive Groups Associated with Initial Ascent to Altitude (Table 9-5)
Sea Level Equivalent Depth (Table 9-4)
What is the proper ascent rate?
What is the proper decent rate?
30 fsw/min, minor variations in the rate of ascent between 20 and 40 fsw/min. (For surface decompression, the ascent rate from the 40fsw water stop to the surface is 40 fsw/min.)
The decent rate on an air dive is not critical but generally should not exceed 75 fsw/min.
when does the decompression stop time commence?
What is the last waster stop for all in-water decompression?
When is a diver eligible for surface decompression?
For in-water decompression on air, the time at the first decompression stop begins when the diver arrives at the stop and ends when he leaves the stop. For all subsequent stops, the stop time begins when the diver leaves the previous stop and ends when he leaves the stop.
The last water stop for all in-water decompression is 20fsw
A diver is eligible for surface decompression upon completion of the 40 fsw stop. If fsw stop is not required by the decompression schedule, the diver may ascend directly to the surface without decompression stops and begin surface decompression
What are the Optional Shallow Water No-Decompression Table?
Found in Appendix 2A, covering a depth range between 30-50 fsw in one-foot increments.
What are Exceptional Exposure Dives defined as?
Any air dive deeper than 190 fsw
Any in -water decompression dive with a total decompression time on air or air/oxygen greater than 90 minutes.
Any SuDO2 dive with a chamber oxygen time greater than 120 minutes (4 Oxygen periods).
Delay in arriving at the first decompression Stop
Delay up to 1 minute
Delay greater than 1 minute, deeper than 50 fsw
Delay greater than 1 minute, shallower than 50fsw
Delay up to one minute in reaching the first decompression stop can be ignored.
Round up the delay time to the next whole minute and add it to the bottom time. Recompile the table and schedule. If no change in schedule is required, continue on the planned decompression. If a change in schedule is required and the new schedule calls for a decompression stop deeper than the diver’s current depth, preform any missed deeper stops at the diver’s current depth do not do deeper.
If a delay in ascent greater than 1 minute occurs shallower than 50 fsw, round the delay time up to the next whole minute and add the delay time to the diver’s first decompression stop.
Delays in Leaving a Stop or Between Decompression Stops
Delay less than 1 minute leaving an air stops.
Delay less than 1 minute between air stops.
Delay greater than 1 minute leaving an air stop or between air stops deeper than 50 fsw.
Delay greater than 1 minute leaving an air stop or between air stops shallower than 50 fsw
When the delay in leaving an air stop is less than 1 minute, disregard the delay. Resume the normal decompression when the delay is over.
If the delay between stops is less than 1 minute, disregard the delay.
Add the delay to the bottom time and recompute table and schedule, if a new schedule is required, pick up the new schedule at the present stop or subsequent stop if delay occurs between stops. Ignore any missed stops or time deeper than the depths at which the delay occurred.
Ignore the delay. Resume the normal schedule upon completion of the delay.
Delays in Leaving a Stop or Between Decompression Stops
Delay leaving an o2 stop at 30fsw or delay between o2 stops at 30 and 20fsw.
Delay in leaving the 20fsw oxygen stop
Delay in Travel from 40fsw to the Surface for Surface Decompression
Subtract any delay in leaving the 30fsw oxygen stop or any delay during travel from 30 to 20 fsw on oxygen from the subsequent 20-fsw oxygen stop time. If delay causes the total time on oxygen deeper than 20 fsw to exceed 30 minutes, shift the diver to air at the 30-minute mark. When the problem has been resolved, shift the diver back to oxygen and resume decompression. Ignore any time spent on air.
Delays leaving the 20-fsw oxygen stop can be ignored. However, do not leave divers on oxygen longer than 30 minutes as described in paragraph 9-8.2.2. Shift the divers to air and remain on air until travel to the surface is possible.
Disregard any delays in travel from the 40 fsw to the surface during surface decompression unless the diver exceeds the allowed 5-minute surface interval. If the diver exceeds the 5-minute surface interval, follow the guidance in paragraph 9-12.6
What is the need for correction with altitude dives?
No correction required at altitudes between sea level and 300 feet.
At altitudes between 300 and 1000 feet, correction is required for dives deeper than 145 fsw (actual depth).
At altitudes above 1000 feet, correction is required for all dives.
What is the correction factor for sealed reference gauges when diving at altitude?
Are pneumofathometer correction factors changed at altitude?
A correction factor of 1 fsw for every 1000 feet of altitude should be added to the reading of a sealed reference gauge before entering table 9-4 (Sea Level Equivalent Depth fsw)
No pneumofathometer correction factors remain unchanged at altitude.
How many hours is required for equilibration at altitude?
How long is required for full acclimatization?
Approximately 12 hours at altitude is required for equilibration.
A longer period is required for full acclimatization.
Ascents above ______ feet should be planned in consultation with a UMO. Commands conducting diving operations above _____ feet may obtain the appropriate decompression procedures from _____ _____
What drugs my be required to prevent the occurrence of altitude sickness?
10,000 feet
10,000 feet
NAVSEA 00C
prophylactic drugs
