9-18
U.S. Navy Diving Manual—Volume 2
Residual nitrogen times corresponding to the depth of the repetitive dive are given
in the body of the lower portion of the table. To determine the residual nitrogen
time for a repetitive dive:
1.
Locate the diver’s repetitive group designation from the previous dive along
the diagonal line above the table.
2.
Read horizontally to the interval where the diver’s surface interval lies. The
time spent on the surface must be between or equal to the limits of the selected
interval.
3.
Read vertically down to the new repetitive group designation. This corre-
sponds to the present quantity of residual nitrogen in the diver’s body.
4.
Continue down in this same column to the row representing the depth of the
repetitive dive. The time given at the intersection is the residual nitrogen time,
in minutes, to be applied to the bottom time of the repetitive dive.
9-9.1.1
Example. A repetitive dive is planned to 98 fsw for an estimated bottom time of
15 minutes. The previous dive was to a depth of 100 (100+1=101) fsw with a
bottom time of 48 minutes. The diver’s surface interval is 6 hours 26 minutes
(6:26). Determine the proper decompression schedule.
1.
Use the 110/50 schedule of the Standard Air Decompression Table to find the
residual nitrogen time of the previous dive. Read across the 50-minute bottom
time row to find the repetitive group designator of M.
2.
Move to the Residual Nitrogen Timetable for Repetitive Air Dives.
3.
Enter the table on the diagonal line at M.
4.
Read horizontally across the line until reaching the surface interval coinciding
with the diver’s surface interval of 6 hours 26 minutes. The diver’s surface
interval falls within the limits of the 6:19/9:28 column.
5.
Read vertically down the 6:19/9:28 column until reaching the depth coinciding
with the repetitive dive depth of 100 fsw to find the residual nitrogen time of 7
minutes.
6.
Add the 7 minutes of residual nitrogen time to the estimated bottom time of 15
minutes to obtain the single equivalent dive time of 22 minutes.
7.
The diver will be decompressed on the 100/22 No-Decompression schedule.
Figure 9-9 depicts the dive profile for the first dive, Figure 9-10 shows the Repeti-
tive Dive Worksheet, and Figure 9-11 shows the dive profile for the repetitive
dive.
