During-Dive Safety Procedures
Critical safety procedures to follow while underwater - from descent to ascent
Diving Safety
Essential Reading
All Levels
Reading time: 10 minutes | By ScuPlan Safety Team
Underwater - No Shortcuts
Once you're underwater, you're in an environment where mistakes can quickly become life-threatening. These safety procedures aren't suggestions—they're protocols developed from decades of experience and, unfortunately, analysis of diving accidents. Follow them religiously.
The Golden Rules Underwater
- Never hold your breath while breathing compressed air
- Always dive with a buddy and stay within visual/physical contact
- Monitor depth, time, and air constantly
- Ascend slowly - no faster than 9-10 meters/30 feet per minute
- Plan your dive, dive your plan - stick to the agreed depths and times
Safe Descent Procedures
Before You Descend
- ✅ Positive buoyancy established at surface
- ✅ OK signal exchanged with buddy
- ✅ Regulator in mouth, breathing normally
- ✅ BCD deflated (except minimal for surface float)
- ✅ Time noted on dive computer
During Descent (Controlled & Slow)
- 🔽 Equalize Early and Often: Start equalizing before you feel pressure
- Every 1-2 meters / 3-6 feet
- Use gentle Valsalva or Frenzel technique
- NEVER force equalization - ascend slightly if needed
- 🔽 Descent Rate: 10-15 meters/30-50 feet per minute maximum
- 🔽 Stay with Buddy: Descend together, not one after the other
- 🔽 Use Descent Line: If available, control rate with rope/anchor line
- 🔽 Breathe Normally: Slow, deep breaths - never hold breath
Stop Descent If:
- Unable to equalize ears or sinuses
- Experiencing vertigo or disorientation
- Buddy signals a problem
- Descending too fast (check computer)
Buddy System Protocols
Maintaining Buddy Contact
The buddy system is your primary safety net. Separation is one of the leading contributors to diving accidents.
Visual Contact Guidelines:
- 👁️ Good Visibility (10m+): Check buddy every 30-60 seconds
- 👁️ Poor Visibility (<5m): Physical contact or visual every 15-30 seconds
- 👁️ Very Limited (<2m): Tether or constant physical contact
Positioning:
- Swim side-by-side or slightly offset
- NOT single-file (buddy out of sight)
- In current: Follow lead diver, stay within 2-3 meters
Lost Buddy Procedure
If you lose sight of your buddy:
- STOP immediately - don't continue the dive
- Look around 360° - make a complete turn
- Search for 1 minute maximum:
- Ascend slowly 3-5 meters while looking
- Check above and below
- If not found after 1 minute: Surface using normal ascent procedure
- At surface: Inflate BCD, signal for help if needed, reunite at pre-planned location
NEVER continue diving alone after losing buddy.
Air Management During the Dive
Rule of Thirds (Recreational Diving)
⅓
Descent & Out
⅓
Return Journey
⅓
Reserve
Example (200 bar / 3000 PSI tank):
- Start: 200 bar / 3000 PSI
- Turn point: 133 bar / 2000 PSI
- Surface minimum: 67 bar / 1000 PSI (never go below 50 bar / 700 PSI)
Monitoring Your Air
- ⏱️ Check SPG (pressure gauge) every 5 minutes minimum
- ⏱️ More frequently at depth (air consumption increases with depth)
- ⏱️ Notify buddy when you reach 100 bar / 1500 PSI
- ⏱️ Signal "low on air" at 70 bar / 1000 PSI
- ⏱️ Begin ascent immediately if you or buddy reaches 50 bar / 700 PSI
Out of Air Emergency
If you run out of air:
- Signal buddy: Hand across throat (out of air)
- Approach buddy: Face to face
- Grab buddy's octopus: Usually on right chest clip or triangle
- Purge octopus before breathing
- Take 2-3 breaths to calm down
- Establish physical contact: Hold buddy's BCD or arm
- Ascend together: Slowly, following normal ascent procedure
Buddy responsibilities:
- Stay calm and breathe normally
- Present octopus clearly
- Maintain physical contact
- Control ascent rate (look at computer)
- Make safety stop if air permits
Depth & Time Monitoring
Why It Matters
Exceeding your planned depth or no-decompression limit (NDL) can lead to decompression sickness (DCS). Monitoring is not optional.
What to Monitor
- 📊 Current Depth: Stay within planned maximum
- 📊 Maximum Depth: Your dive computer records this
- 📊 Bottom Time: Time spent at depth (not total dive time)
- 📊 NDL (No-Decompression Limit): Time remaining before deco required
- 📊 Ascent Rate: Should be 9-10m (30ft) per minute or slower
If You Exceed NDL
If your computer shows you've entered decompression:
- Don't panic - small overages are manageable
- Signal buddy - show computer
- Follow computer instructions:
- Ascend to deco stop depth
- Complete required stop time
- Do NOT skip deco stops
- After surfacing:
- Monitor for DCS symptoms for 24 hours
- No flying for 24 hours minimum
- Consider ending diving for the day
Safe Ascent Procedures
The Most Critical Phase
More accidents happen during ascent than any other phase. Rapid ascent can cause:
- Decompression sickness (DCS)
- Arterial gas embolism (AGE)
- Lung overexpansion injuries
Proper Ascent Technique
- Signal buddy: Thumbs up (end dive)
- Check surroundings: Look up for boats, obstacles
- Start ascent:
- Vent BCD air as you ascend
- Follow ascent line if available
- Look at dive computer constantly
- Maximum rate: 9-10m (30ft) per minute
- Follow your smallest bubbles (they rise at safe speed)
- Safety Stop (5m / 15ft depth):
- MANDATORY on all dives
- Duration: 3-5 minutes minimum
- Maintain neutral buoyancy
- Continue breathing normally
- Final equipment/buddy check
- Final Ascent to Surface:
- Same slow rate (9-10m/min)
- Look up continuously
- Extend right arm above head (protection from boats)
- Rotate 360° as you surface (check for boats)
- At Surface:
- Inflate BCD immediately
- Signal "OK" to boat/shore
- Switch to snorkel (conserve tank air)
NEVER:
- Race your buddy to the surface
- Hold your breath during ascent
- Skip the safety stop (unless emergency)
- Ascend faster than your bubbles
- Ascend faster than 9-10m/min rate
Emergency Situations & Responses
1. Uncontrolled Ascent
Cause: Over-inflation of BCD, buoyancy loss of control
Action:
- Vent ALL air from BCD (dump valves and deflator)
- Flare body horizontally to increase drag
- If still ascending: Ditch weights (last resort)
- After surface: Breathe 100% oxygen if available, monitor for DCS
2. Entanglement
Cause: Fishing line, kelp, wreck debris
Action:
- STOP all movement - struggling makes it worse
- Signal buddy for help
- Use dive knife/cutter to carefully cut free
- Work slowly and methodically
- If unable to free yourself: Use octopus, buddy assists
3. Equipment Malfunction
Freeflow regulator:
- Partially cover mouthpiece with tongue
- Signal buddy
- Switch to octopus if air loss is excessive
- Begin controlled ascent
BCD inflator stuck open:
- Disconnect inflator hose from BCD
- Vent air manually
- Use oral inflation for buoyancy control
- End dive - ascend normally
4. Mask Flood/Loss
- Don't panic - you can breathe without mask
- Hold regulator firmly in mouth
- If mask is displaced: Reposition and clear
- If mask is lost: Continue dive holding regulator, or end dive
- Ascend normally - can see enough without mask
During-Dive Best Practices Summary
✅ DO:
- Stay with your buddy
- Monitor depth, time, and air constantly
- Equalize early and often
- Breathe slowly and deeply
- Ascend slowly (9-10m/min)
- Make a safety stop on every dive
- Communicate clearly with buddy
- Trust your training
❌ DON'T:
- Hold your breath
- Dive alone or lose buddy
- Exceed planned depth or time
- Skip safety stops
- Ascend faster than 9-10m/min
- Ignore low air warnings
- Panic in emergencies
- Continue dive if uncomfortable
Emergency Quick Reference
Out of Air:
- Signal buddy (hand across throat)
- Get octopus
- Breathe, calm down
- Ascend together slowly
Lost Buddy:
- Stop and look 360°
- Search 1 minute max
- Surface if not found
Ascent Rate:
MAX: 9-10m (30ft) per minute
Safety Stop:
5m (15ft) for 3-5 minutes
DAN Emergency
+1-919-684-9111
24/7 Diving Emergency Hotline