Quick Answer — What Is the No-Decompression Limit at My Depth?
A no-decompression limit, or NDL, is the maximum time you can spend at a given depth and still ascend directly to the surface at a normal rate without a required decompression stop. It shortens sharply with depth, because nitrogen loads into tissue faster as pressure rises.
Every row of the air table this calculator uses, from 46 CFR Part 197, Appendix A:
- 35 ft — 310 minutes
- 40 ft — 200 minutes
- 50 ft — 100 minutes
- 60 ft — 60 minutes
- 70 ft — 50 minutes
- 80 ft — 40 minutes
- 90 ft — 30 minutes
- 100 ft — 25 minutes
- 110 ft — 20 minutes
- 120 ft — 15 minutes
- 130 ft — 10 minutes
Read the shape of that list rather than any single row. Going from 60 ft to 80 ft cuts the limit from 60 minutes to 40; another 20 feet down to 100 ft cuts it to 25; by 130 ft, the recreational depth ceiling, you have ten minutes. Depth is not a linear cost.
This is a planning and learning reference, not a dive computer. It plans one dive, in isolation, at a single depth. It does not track residual nitrogen from an earlier dive, does not adjust for altitude, and cannot see what actually happens in the water. Dive within your certification, follow your computer, and make a safety stop.