Dec '25 (edited) • 🚑 Incidents
INCIDENT CASE STUDY: When Production Pressure Kills Safety Culture
Date: 10 December 2018
Location: Las Palmas, Gran Canaria, Spain
Company: Otech Marine Services
Client: Diamond Offshore
Project: Ocean Great White - Thruster Anode Welding
Incident Type: Type 2 Decompression Sickness (Vestibular Bends)
Outcome: Diver airlifted to Tenerife for hyperbaric treatment
THE INCIDENT
A commercial diver suffered Type 2 DCS with vestibular symptoms (severe dizziness, balance
loss, ear pain) after a 56-minute bottom time at 60ft. Within 10 minutes of surfacing, the diver
reported symptoms. What followed was a textbook example of how NOT to manage a diving
emergency.
THE SETUP: Recipe for Disaster
Aggressive Schedule
Dive Tables Used: USN Rev. 7 at 60ft/63min
What Should Have Been Used: Norwegian tables (more conservative)
Reality: Diver had completed 5 consecutive days of hard repetitive diving
Red Flag: No formal deviation request submitted for using non-Norwegian tablesThe Dive Profile (Last Day)
Date Bottom Time Surface Interval Max Depth Table Used
05.12.18 38 mins N/A 16.6m 18.3/63 60/63
06.12.18 38 mins 38 hrs 18 mins 13.5m 15.2/92 50/92
08.12.18 57 mins 26 hrs 56 mins 17.4m 18.3/63 60/63
09.12.18 24-45 mins 24 hrs 45 mins 17.6m 18.3/63 60/63
09.12.18 56 mins 19 hrs 34 mins 17.6m 18.3/63 60/63
Bottom line: This diver was being pushed to the absolute limit, repeatedly.
THE CRITICAL FAILURES
1. REFUSAL TO RECOMPRESS IMMEDIATELY
What Happened:
Diving Supervisor decided AGAINST using the onsite DDC
Reason given: "Faulty O2 analyzer - can't control O2% in chamber"
Diver left breathing surface O2 instead
Why This Was Wrong:
Treatment Table 6 requires recompression to 60ft IMMEDIATELY
O2 analyzer failure does NOT prevent chamber use
Could have vented chamber and topped up with fresh gasEvery minute delayed = increased risk of permanent injury
The Expert Opinion:
"We should have used the Otech DDC immediately (treatment table 6) with direct
communication with the hyperbaric doctor and not wait for the ambulance and the
Hyperbaric facilities of the island because Lewis had obvious neurological signs and
symptoms of DCI."
- Trainee DMT on scene (voice shouted down)
2. EMERGENCY RESPONSE PLAN FAILURE
The Cascade of Delays:
Time Event Issue
00:12 Diver surfaces, reports symptoms -
00:16 Team ready to recover diver -
00:19 112 Emergency activated ✓ Correct
00:20 Injured person at quayside on O2 ⚠ Should be in chamber
00:31 High pulse (102bpm), nervous, dizzy ⚠ Symptoms worsening
00:32 First contact with hyperbaric facility Too late
00:34 Ear blocked, neurological exam continues Time wasting
00:40 O2 supply runs out, switches to normobaric Critical delay
00:50 Increasing pulse (100bpm), vomiting Deteriorating
00:53 Ambulance arrives, 112 reactivated Wrong ambulance type
01:13 Arrive at contracted chamber - CLOSED Epic failure
01:15 Confirm transfer to hospital needed -
01:20 Ambulance arrives at hospital -
01:38 Told diver needs transfer to Tenerife -
01:43 Hospital doctor speaks with chamber doctor -
02:01 Approved for Tenerife transfer -
02:54 Helicopter arrives -
03:00 Diver finally transferred Nearly 3 hours post-incident
The Contracted Facility Issue:
Hiperbáricas Canarias SL was contracted for 24/7 coverage
When they arrived at 01:13, it was CLOSED
"Available 24 hrs per day, every day, if proved not to be manned on the day of the
incident"
This is NOT 24/7 coverage - this is a lie
3. NO DIVING DOCTOR INVOLVEMENT
Critical Oversight:
Otech had a Diving Doctor on the Emergency Response chart
The doctor was NEVER notified that diving operations were ongoing
No medical oversight during planning phase
Doctor only contacted AFTER the incident occurred
What Should Have Happened:
Diving Doctor notified before project start
Diving Doctor available for emergency consultation
Diving Doctor involved in emergency response drills
4. LACK OF SAFETY LEADERSHIP
Multiple Voices Ignored:
From the trainee DMT on scene:"I am a trained DMT and from my experience I would class that as a type 2, neurological
DCI, the treatment for which is immediate re-compression and USN treatment table 6. He
was exhibiting all the classic signs yet people were coming up with outrageous comments
such as 'it's just reverse block' (on account of him saying he had ear pain) The vestibular
symptoms he had exhibited: vertigo, dizziness and now vomiting told me he had a bubble
in his ear and he needed to be placed in a chamber, at depth, immediately."
The supervisor's decision was not based on medical best practice - it was based on:
Broken equipment (O2 analyzer)
Local regulations requiring hyperbaric doctor authorization
Fear of doing something wrong
Result: Multiple trained medics on scene, all shouted down by a supervisor making a life threatening decision.
THE ROOT CAUSES
1. Production Pressure
Project behind schedule
Aggressive dive plan to catch up
Safety margins deliberately eroded
No consideration of diver fatigue
2. Inadequate Planning
Risk assessment did not address:
Decompression sickness potential
Diving fatigue accumulation
Emergency response equipment checks
USN tables used without formal comparison to Norwegian standard
No safety margin in schedule
3. Equipment Not Maintained
O2 analyzer on DDC not functional
No backup analyzer available
Equipment checks not performed before project start
4. Emergency Response Not Tested
No emergency drills conducted
Personnel didn't know the response plan
Contracted hyperbaric facility status not verified
Wrong ambulance dispatched initially
5. Competence Gaps
Diving Supervisor lacked hyperbaric treatment familiarity
Decision-making authority given to least qualified person
Trained DMTs on scene were overruled
WHAT SHOULD HAVE HAPPENED
Immediate Response (First 15 Minutes)
1. 00:12 - Diver reports symptoms
2. 00:13 - Decision made: PUT HIM IN THE CHAMBER
3. 00:15 - Diver in DDC, compressed to 60ft
4. 00:16 - Contact Diving Doctor for guidance
5. 00:17 - Begin Treatment Table 6
6. 00:20 - Activate emergency services for standby
7. 00:25 - Symptoms stabilizing under pressure
The Proper Equipment Response
"O2 analyzer broken" should have triggered:
Use chamber anyway
Vent chamber regularly (every 15 mins)
Top up with fresh gas
Monitor diver condition closely
Can control depth without O2 analyzer working
The Proper Medical Response
"Spanish regulations require hyperbaric doctor"
This is for RUNNING the facility
Emergency first aid doesn't require permission
Treatment Table 6 is FIRST AID, not medical treatment
Hyperbaric doctor can be consulted BY PHONE while treating
THE REAL LESSONS
For Divers:
1. Your safety depends on the weakest link - In this case, it was the supervisor's
decision-making
2. Production pressure kills - 5 days of aggressive diving led directly to this incident
3. Emergency plans are worthless if not practiced - Every single element of the
emergency response failed
4. Speak up, even if you're junior - The trainee DMT was right, but was shouted down
For Supervisors:
1. When in doubt, RECOMPRESS - You can always decompress a healthy diver, you can't
un-injure a bent one
2. Equipment failures are not excuses - Broken O2 analyzer? Use the chamber anyway
3. "Spanish regulations" are not a shield - Providing emergency first aid is not practicing
medicine
4. Test your emergency plan - If you've never run a drill, your plan is fiction
For Companies:
1. 24/7 hyperbaric coverage means 24/7 - Not "available if we feel like answering"
2. Involve your Diving Doctor BEFORE operations start - Not after someone gets hurt
3. Conservative dive planning isn't optional - Norwegian tables exist for a reason
4. Emergency equipment must be functional - If the O2 analyzer is broken, FIX IT or don't
dive
THE FOLLOW-UP QUESTIONS
The incident report raised several critical questions that Otech needed to address:
Planning Issues:
Why was the project planned without appropriate regard to depth and decompression
tables?
Why were necessary risk assessments not made related to diving and decompression?
Why was the Norwegian table not used as the standard?
Emergency Response Issues:
Why was the diver not recompressed immediately?
Why was the Otech Diving Doctor not notified of the project?
Why was the emergency response not in accordance with IDMS-1?
Why did the preparation for this project breach several written IDMS routines?
Systemic Issues:
Why did Otech management need to strengthen diving competence at the Las Palmas
site?
Why did risk reviews need to take into consideration the competence of diving
supervisors in hyperbaric treatment?
Why did the Diving Doctor need to be involved at the start of ANY diving operation?
CORRECTIVE ACTIONS REQUIRED
The investigation concluded with specific corrective actions:Immediate Actions:
1. Dive planning must be more conservative - Always compared with Norwegian Diving
Tables
2. Emergency Response training - Full cycle with diver recompressed to 60fsw as
standard, DDC operation must be highlighted
3. Diving Doctor involvement - Must be notified when diving campaigns are ongoing and
have qualified support in case of problems
4. Life Critical Services checks - If dependence on external suppliers continues, must be
subjected to continual availability checks
Long-term Changes:
1. Strengthen diving competence at operational sites
2. Focus risk reviews on supervisor competence in hyperbaric treatment
3. Ensure Diving Doctor involvement from project inception
4. Implement mandatory emergency response drills before projects start
THE UNCOMFORTABLE TRUTH
This incident report was created by a "well-respected, well-known diving industry professional"
and signed off by Otech's CEO. It represents a rare moment of honesty in an industry that
often buries its mistakes.
But here's what the report doesn't say:
Did the diver make a full recovery?
Was anyone held accountable?
Were the corrective actions actually implemented?Did Otech change its safety culture?
The report ends with professional recommendations. It doesn't end with "and we fired the
supervisor who made a life-threatening decision" or "and we compensated the diver for
permanent injury."
That's the reality of this industry.
DISCUSSION QUESTIONS
1. If you were the standby diver and witnessed the supervisor refusing to use the
chamber, what would you do?
2. The trainee DMT knew the right answer but was shouted down. How do you build a
safety culture where junior personnel can challenge dangerous decisions?
3. Otech had written procedures, trained personnel, and contracted hyperbaric
support. How did EVERYTHING still fail?
4. What would you have done differently in the first 5 minutes after the diver reported
symptoms?
5. This happened on a vessel called "Ocean Great White" working for Diamond
Offshore (major client). Does working for a big client create pressure to cut
corners?
FINAL THOUGHTS
This incident happened in 2018. The report was issued in February 2019.
The Global Diving Support Network shared it in December 2025 as a "lessons learned" document.
Seven years later, are we learning?
Or are we just creating more incident reports that get filed away, read by a few people, and
then forgotten while the next diver gets bent because production was behind schedule and
someone decided that 63 minutes at 60ft for the fifth day in a row was "acceptable"?
Your career. Your body. Your decision to work for companies that value safety over
schedule.
Choose wisely.
REFERENCES
GDSN Incident Report GDSN-002-Otech Duty of Care
Otech Marine Services Internal Investigation Report
Norwegian Diving and Treatment Tables (IDMS-3)
US Navy Diving Manual Rev. 7
Personal statements from dive team personnel
This incident is being shared for educational purposes as part of the Beyond the Surface
commercial diving education program. All information is sourced from publicly available
incident reports.
If you have additional information about this incident or its outcome, please share in the
comments below.
Remember: Every incident report represents someone who got hurt. These aren't just stories -
they're warnings written in someone else's pain.
Lewis, the diver affected is pictured below with his Dad Derek. Remember these incidents are real and affect real people. Learn from them.
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INCIDENT CASE STUDY: When Production Pressure Kills Safety Culture
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