6-26 Change A
U.S. Navy Diving Manual—Volume 2
NORMAL AND MAXIMUM LIMITS FOR AIR DIVING
Depth fsw
(meters)
Limit for Equipment
Notes
60 (18)
MK 21 MOD 0 diving equipment, maximum working limit without
Emergency Gas Supply (EGS)
a
60 (18)
MK 20 MOD 0 equipment surface-supplied
a
60 (18)
Maximum depth for standby scuba diver using a single cylinder
with less than 100 SCF capacity
100 (30)
Open-circuit scuba with less than 100 SCF cylinder capacity
b
130 (40)
Open-circuit scuba, normal working limit
b
190 (58)
Open-circuit scuba, maximum working limit with Commanding
Officer’s and Officer-in-Charge’s permission
b, d
190 (58)
MK 21 MOD 1 and EXO BR MS (air) diving equipment with EGS,
normal working limit
c, d, e
285 (87)
MK 21 MOD 1 and EXO BR MS (air) diving equipment with EGS,
maximum working limit, exceptional exposure with authorization
from the Chief of Naval Operations (N873)
c, d, e
General Operating Notes (Apply to all):
1.
These limits are based on a practical consideration of working time versus decompression time and
oxygen-tolerance limits. These limits shall not be exceeded except by specific authorization from the Chief
of Naval Operations (N873).
2.
Do not exceed the limits for exceptional exposures for the Standard Air Decompression Table.
3.
In an emergency, any operable recompression chamber may be used for treatment if deemed safe to use
by the Diving Supervisor.
Specific Notes:
a.
When diving in an enclosed space an EGS must be used by each diver.
b.
Under normal circumstances, do not exceed the limits of the No-Decompression Table. Dives requiring
decompression may be made if considered necessary with approval by the Commanding Officer or
Officer-in-Charge of the diving command. The total time of a scuba dive (including decompression) shall
not exceed the duration of the apparatus in use, disregarding any reserves.
c.
A Diving Medical Officer is required at the site for all air dives deeper than 190 fsw, where the maximum
working depth of the diving apparatus may be exceeded, and for exceptional exposure dives.
d.
All planned air decompression dives deeper than 130 fsw require a certified recompression chamber on
site. An on-site chamber is defined as a certified and ready chamber accessible within 30 minutes
of the dive site by available transportation.
e.
The Exceptional Exposure Tables, printed in red in the Standard Air Tables, have a significantly higher
probability of DCS and CNS oxygen toxicity.
Figure 6-14. Normal and Maximum Limits for Air Diving.
