What is the single depth limit for 30 fsw?

• A. 60 minutes
• B. 45 minutes
• C. 25 minutes
• D. 80 minutes

Answer: (D)

The main idea here is the time you can stay at a fixed depth without needing decompression stops. That maximum bottom time at 30 feet is called the single depth limit. It tells you how long you can remain at that depth and still ascend directly to the surface without special decompression procedures.

For 30 fsw, the single depth limit is 80 minutes. This means you could plan a dive that spends up to 80 minutes at 30 feet and then ascend with no mandatory decompression stops. If you go longer than 80 minutes at that depth, you’d be entering decompression territory and would need staged stops to safely off-gas nitrogen during ascent.

In practice, you’d plan your dive around this limit using a dive table or computer, and you’d adjust for contingencies like additional gas, a surface interval before a second dive, and any planned ascent profiles.