How long can you stay underwater while scuba diving?

The time you can stay underwater depends on how deep you go, how fast you breathe, and how much gas you carry. On a typical recreational dive to around 40 feet (12 meters), most divers stay underwater for 45 to 60 minutes before reaching their reserve pressure. At deeper depths, the higher pressure makes you use gas faster, so bottom time becomes much shorter.

Most dives end because the tank is running low, not because of a time limit. Recreational divers have wide safety margins for how long they can stay underwater before needing special decompression procedures. In normal diving conditions, you will reach your gas limit well before that becomes a concern. The main factor is how calmly and efficiently you breathe, which improves with experience.

Recreational Gas Planning Guide for Open Water Divers

Practical recreational gas planning: RMV basics, Minimum Gas Reserve, and turn pressure methods. Equations and examples included.

RMV vs. SAC: What’s the Difference and Why It Matters

Learn the difference between SAC and RMV. Understand why experienced divers rely on RMV and how to calculate it correctly.