46 CFR Appendix A to Part 197 - Appendix A to Part 197—Air No-Decompression Limits
The following table gives the depth versus bottom time limits for single, no-decompression, air dives made within any 12-hour period. The limit is the maximum bottom time in minutes that a diver can spend at that depth without requiring decompression beyond that provided by a normal ascent rate of 60 fsw per minute. (Although bottom time is concluded when ascent begins, a slower ascent rate would increase the bottom time thereby requiring decompression.) An amount of nitrogen remains in the tissues of a diver after any air dive, regardless of whether the dive was a decompression or no-decompression dive. Whenever another dive is made within a 12-hour period, the nitrogen remaining in the blood and body tissues of the diver must be considered when calculating his decompression.
Air No-Decompression Limits
Depth (feet): |
|
---|---|
35 | 310 |
40 | 200 |
50 | 100 |
60 | 60 |
70 | 50 |
80 | 40 |
90 | 30 |
100 | 25 |
110 | 20 |
120 | 15 |
130 | 10 |
(Source: U.S. Navy Diving Manual, 1 September 1973.)