Safety
What Is a Safety Stop?
The three-minute pause at the end of almost every dive, what it does, and how it differs from a decompression stop.
A safety stop is a three-minute pause at about five metres (15 feet) at the end of a dive. It gives your body extra time to release absorbed nitrogen gently before you surface, lowering the risk of decompression sickness. It is not strictly mandatory on a normal no-decompression dive, but it is standard practice and strongly recommended on any dive deeper than about 10 metres.
- Depth
- ≈5 m / 15 ft
- Duration
- 3 minutes
- Purpose
- Off-gas nitrogen
- When
- End of almost every dive
If you have watched divers hovering quietly near the surface at the end of a dive, looking at their computers and doing nothing in particular, you have seen a safety stop. It is one of the simplest and most valuable habits in diving.
What a safety stop actually does
During your dive your body absorbs extra nitrogen under pressure. As you ascend, that nitrogen comes back out. The final few metres are where pressure changes most rapidly, so pausing at five metres for three minutes gives the nitrogen a calm, controlled head start at leaving your tissues before you break the surface. It is a low-effort insurance policy against decompression sickness.
Safety stop vs decompression stop
These two sound similar but are different. A safety stop is optional but recommended: you choose to do it on dives that stayed within your no-decompression limits. A decompression stop is mandatory: if you exceed your no-stop limit, your computer requires one or more stops, and you must complete them before surfacing or you risk serious DCS. Recreational diving is planned to avoid mandatory deco stops entirely.
| Safety stop | Decompression stop | |
|---|---|---|
| Required? | Recommended, optional | Mandatory |
| When | Within no-stop limits | After exceeding the limit |
| Typical depth | 5 m | Varies, often deeper too |
| Skipping it | Slightly higher risk | Dangerous |
How to do a good safety stop
- Ascend slowly to five metres: Slow your ascent as you approach the stop, no faster than about 9 to 10 metres per minute.
- Hold your depth for three minutes: Use good buoyancy to stay steady at five metres. A reef, a mooring line or a delayed surface marker buoy line gives you a helpful reference.
- Watch your computer and your buddy: Stay relaxed, keep breathing slowly, and stay together as a team.
- Surface gently: After three minutes, make a slow, controlled ascent for the last few metres, looking up as you go.
In rough water or strong current a safety stop can be hard to hold precisely. Do your best, prioritise a slow ascent above all, and use a line or reference whenever one is available.
Never miss a safety stop
The Diving Standard app counts down your safety stop and tracks your ascent rate, so you surface calm and within safe limits every time.
Get the Diving Standard appFrequently asked questions
Is a safety stop mandatory?
On a normal no-decompression dive a safety stop is recommended rather than strictly mandatory, but it is standard practice on any dive deeper than about 10 metres. A decompression stop, by contrast, is always mandatory.
What happens if you skip a safety stop?
Occasionally skipping a safety stop on a shallow, conservative dive carries only a small added risk. But because it costs just three minutes and meaningfully lowers decompression-sickness risk, divers treat it as a routine part of every dive.
Why is a safety stop done at 5 metres?
Five metres is shallow enough that most nitrogen off-gassing happens there, yet deep enough to keep you below the surface chop and in control. Three minutes at that depth gives nitrogen time to leave gently.