Both safety stops and decompression stops involve pausing during your ascent, but they serve different purposes, have different obligations, and carry different consequences if skipped.
Safety Stops
A safety stop is a voluntary pause at 15 feet (5 meters) for three minutes at the end of any dive deeper than about 30 feet. It's not required by your dive computer and isn't mathematically necessary for dives within no-decompression limits. It's a precaution — an insurance policy that gives your body extra time to off-gas nitrogen before you surface.
Safety stops are recommended by every training agency (PADI, SSI, NAUI, SDI) and by every dive computer manufacturer. Skipping a safety stop on a no-deco dive doesn't create an immediate emergency, but it removes a margin of safety that exists to account for individual variability in gas elimination.
Decompression Stops
A decompression stop is a mandatory pause at a specific depth for a specific duration, calculated by your dive computer because you have exceeded your no-decompression limit. Your computer tells you exactly where to stop (depth) and for how long (time). These stops are not optional — they're computed obligations based on the gas loading your tissues have accumulated.
Skipping or shortening a required decompression stop significantly increases the risk of decompression sickness. The nitrogen in your tissues needs controlled time to diffuse back into your bloodstream and be exhaled through your lungs. Ascending without completing stops allows that gas to form bubbles in your tissues and bloodstream.
Key Differences
| Attribute | Safety Stop | Deco Stop |
|---|---|---|
| Required? | Recommended, not mandatory | Mandatory |
| Depth | 15 ft / 5m (standard) | Variable — computer-specified |
| Duration | 3 minutes (standard) | Variable — computer-calculated |
| Triggered by | Diver choice / best practice | Exceeding NDL |
| Risk if skipped | Reduced safety margin | Significant DCS risk |
| Certification needed | None — all divers should do it | Decompression diving training |
Practical Guidelines
Do a safety stop on every dive deeper than 30 feet. It costs three minutes and adds meaningful protection. If you accidentally enter decompression (your computer shows required stops), don't panic — follow your computer's instructions, make the indicated stops, and ascend at the recommended rate. Decompression stops are manageable as long as you have enough air to complete them.