What Is a Safety Stop in Scuba Diving?

Why Do We Do a Safety Stop?

During every dive, your body absorbs nitrogen from the breathing gas. A slow ascent combined with a short stop allows this nitrogen to leave your tissues gradually and safely.

• Reduces residual nitrogen
• Adds safety after deeper or longer dives
• Helps compensate for minor ascent rate variations
• A standard best practice in recreational diving

In short: We dive safe and conservative.

Safety Stop vs. Decompression Stop – What’s the Difference?

Safety Stop (Recommended)

• Recommended, not mandatory
• Used in recreational, no-decompression dives
• Typically 3 minutes at 5 meters
• Can be skipped if necessary (air, conditions, emergency)
• A direct ascent is safe if ascent rates are respected

Decompression Stop (Mandatory)

• Mandatory
• Required in decompression diving
• Cannot be skipped without serious risk
• Used when a dive exceeds the no-decompression limit (NDL)
• Nitrogen saturation requires staged decompression

In decompression diving, divers may perform multiple stops at different depths and may switch to different decompression gases to accelerate nitrogen elimination (depending on the dive plan and breathing gases used).

Decompression Gases & Oxygen Considerations

In technical diving, different breathing gases can be used to optimize nitrogen elimination. A common example is using 100% oxygen at 6 meters (≈20 ft).

Important: At depths deeper than 6 meters, pure oxygen becomes toxic due to increased partial pressure of oxygen (PPO₂).

Learn more about oxygen exposure and limits here: https://changdiving.com/en/posts/scuba-knowledge/nitrox-info/

More about gas planning and breathing rates here: https://changdiving.com/en/posts/scuba-knowledge/gas-consumption/

Can a Safety Stop Be Skipped?

Yes — a safety stop can be skipped if required, as long as you are within no-decompression limits and you ascend slowly and controlled.

Maximum ascent rates:

• Traditional standard: 18 meters per minute
• Modern dive computers often use: 9 meters per minute

A slow, controlled ascent is always more important than the stop itself.

How to Perform a Safety Stop Properly

Executing a proper safety stop requires good buoyancy control and awareness. Here's how to do it right:

1. Start your ascent slowly – aim for 9 meters per minute (or follow your dive computer's recommendations)
2. Reach 5 meters depth and establish neutral buoyancy
3. Stay at 5 meters for 3 minutes – use a visual reference if available (reef, anchor line, SMB line)
4. Monitor your depth – avoid floating up or sinking down
5. Check your dive computer regularly during the stop
6. Signal to your buddy before ascending to the surface

Pro tip: If diving from a boat in Koh Chang, use the anchor line or deploy a surface marker buoy (SMB) for a stable reference point during your safety stop.

Common Mistakes During Safety Stops

Even experienced divers sometimes make these mistakes during safety stops:

• Poor buoyancy control – floating up and down instead of staying stable at 5 meters
• Holding your breath – always breathe normally during the stop
• Ascending too quickly before or after the stop
• Not monitoring your computer – missing important information or warnings
• Losing your buddy – always do safety stops together
• Getting separated from the boat – especially in currents (common around Koh Chang dive sites)
• Ignoring your air supply – always ensure you have enough gas (minimum 50 bar reserve)

Want to improve your buoyancy and dive skills? Our Advanced Open Water Diver Course includes peak performance buoyancy training!

Dive Computers and Safety Stops

Modern dive computers make safety stops easier and safer. Most dive computers feature:

• Safety stop countdown timer – automatically triggered when you reach 5 meters
• Depth alarm – warns you if you drift too shallow or deep
• Ascent rate warning – prevents you from ascending too fast
• Visual and audible alerts – helps you stay on track
• NDL (No-Decompression Limit) display – shows remaining bottom time

Some advanced computers even recommend deep stops (e.g., at 15 meters on deeper dives) for additional safety margin.

Note: If your computer shows a mandatory decompression stop, you must follow it – this is no longer optional like a safety stop.

New to dive computers? Learn everything about using them correctly: How to Use a Dive Computer – Complete Guide

Learn more about dive equipment and dive computers or rent quality equipment during your fun dives with us.

Safety Stops in Koh Chang's Diving Conditions

Diving around Koh Chang, Thailand presents unique conditions that affect safety stop procedures:

Currents

Some Koh Chang dive sites experience moderate currents. During your safety stop:

• Stay close to the reef or anchor line for shelter
• Use a surface marker buoy (SMB) if drifting away from the boat
• Communicate with your buddy – hold hands if necessary

Visibility

Visibility in Koh Chang ranges from 5 to 25 meters depending on season and conditions. In lower visibility:

• Stay extra close to your buddy
• Use your dive computer's depth display rather than visual references
• Deploy an SMB for boat pickup

Popular Dive Sites for Practicing Safety Stops

Great sites to practice your safety stops in Koh Chang:

• HTMS Chang Wreck – shallow wreck with excellent mooring line
• Hin Luk Bat – protected reef with good visibility
• Three Finger Reef – pinnacles provide shelter from current

Explore all our Koh Chang dive sites and book your day trip to practice proper safety stop techniques!

What Happens If You Skip a Safety Stop?

Skipping a safety stop occasionally (within NDL and with proper ascent rates) is generally considered safe. However, there are risks:

Decompression Sickness (DCS) Risk

While recreational no-decompression diving is designed to allow direct ascents, skipping safety stops regularly increases your risk of decompression sickness (DCS), also known as "the bends."

DCS Symptoms

Common symptoms of decompression sickness include:

• Joint and muscle pain (especially shoulders, elbows, knees)
• Fatigue and weakness
• Dizziness and vertigo
• Numbness or tingling
• Difficulty breathing
• Skin rash or itching

If you suspect DCS: Seek immediate medical attention. In Koh Chang, contact DAN (Divers Alert Network) and arrange transport to a hyperbaric chamber.

Contributing Factors

Your DCS risk increases if you:

• Do repetitive dives without proper surface intervals
• Dive deep (close to NDL limits)
• Ascend too quickly
• Are dehydrated or fatigued
• Fly too soon after diving (wait 18-24 hours)
• Have a patent foramen ovale (PFO)

Bottom line: Always do your safety stop when possible. It's a simple 3-minute habit that significantly reduces risk.

All our diving activities include dive insurance options for your peace of mind.

Safety Stop vs. Decompression Stop – Quick Comparison

Want to learn technical diving? Start with our Advanced Nitrox Course – the gateway to decompression diving!

Learn Proper Safety Stop Techniques in Koh Chang

Whether you're a beginner or experienced diver, proper safety stop technique is essential for safe diving. At Chang Diving Center, we teach and reinforce safety stops in all our courses:

• Open Water Diver Course – learn the fundamentals of safety stops
• Advanced Open Water Diver – improve buoyancy control for perfect safety stops
• Deep Diver Specialty – practice deep safety stops (15m) and extended stops
• Rescue Diver – learn emergency procedures and proper ascent management

Join our fun dives to practice your safety stop skills in Koh Chang's beautiful dive sites!