Unexplained diving accident: when the doubt arises

Unexplained diving accident

Some diving accidents occur when nothing in the profile of the dive, the condition of the person, the environment,… can explain them.

Indeed, if some diving accidents have an obvious cause and others turn out to be a series of mistakes never to be made, there is still the “unexplained” diving accident.

Of course, far be it from me to say that some of the accidents would be deserved. No, but these come about as a result of carelessness, non-compliance with basic safety rules, a health problem,…

Unexplained diving accidents occur while all safety rules have been respected. Although every effort has been made to determine the cause, there are still questions for divers who have undergone them and the medical team who followed them.

This is the case of the unexplained diving accident that happened to Stéphane at the beginning of 2019, just after we met at Lake Lioson.

For him, as part of our common passion, it was normal to share experiences. This is in order to provide certain elements or clues to possible questions that everyone could legitimately have.

Also, without any taboos or embarrassment, Stéphane wanted to share with you his dive of February 23th 2019 through my blog.

Under no circumstances will the subject go beyond mere testimony to enter the medical field. This is because Stéphane is not a doctor (MD).
Des brumes sur le lac de Genève cachent en partie les montagnes
Brume sur le lac de Genève | © Stephane Egger

The dive

On Saturday 23 February 2019, with his buddy, Stéphane dives next to the Château de Chillon located near Villeneuve in Switzerland. The dive starts at 09:59 am from the small beach. With his buddy, they descend in a proper way along the rope to a depth of 41.8 m. They then make a turn to go to the left and continue diving slightly above 40 meters.

“A little square dive without excess,” Stéphane will say.

They then continue the dive by exploring the Z-shaped cliff as always. The objective is to have a slow ascent adapted to their profile established before the dive.

All stop times were very strictly respected. They even do 10 more minutes at a depth of 3 meters to watch small crayfish. The dive will end after 55 minutes without any ascent or other problems.

Chateau de Chillon vu sous l'eau avant l'accident de plongée immérité
Vue aquatique du chateau de Chillon | © Stephane Egger

Stéphane and his buddy get out of the water, change and drink tea before going to the waterfront to complete their logbooks.

The diving accident occurs: first aid

About 45 minutes after they surfaced, Stéphane’s right ear was slightly blocked. About 10 minutes later, he starts to sweat and loses his balance. Even fully on the ground, he “pitches”. He then breathes stage tank containing 80% of oxygen. However, it is useless and he starts vomiting all the time.

“I would have thought I was on a boat in the middle of a storm with 15-metres waves,” he says.

Immediately his buddy and the other divers called 144 (local rescue) and secured him to avoid a possible fall.

Caring about Stephane

When the ambulance arrives (about 10 minutes later) the rescuers do the first tests and call DAN immediately. The order is immediately given to transport Stéphane by helicopter to the hyperbaric chamber of the University Hospital of Geneva HUG (6 minutes Villeneuve / Geneva).

When the helicopter takes off and at about 20 meters high, Stéphane feels a “clock” in his ear and finds a better hearing.

When he arrived at the hyperbaric service, he was quickly and professionally taken care of by a Hyperbaric teacher and his assistant. A few basic balance tests later, they diagnose a vestibular problem of the inner ear. Stéphane will then be transfered to the hyperbaric chamber for 5 hours at -18 metres. After that, he can reach the room by walking himself without help. To the great surprise of the medical profession. According to these, it usually takes 2 to 3 sessions to be able to walk normally and alone.

Continuation of care

On Sunday 24 February at 09h00, Stéphane has a second safety  hyperbaric chamber treatment for 2h at – 15 meters.

“The chamber alone is very long and not really funny, the only interludes are every 30 minutes for “rinsing” (remove the 100% oxygen mask and breathe the compressed air 21% of the chamber),” says Stéphane.

After this second visit, the staff offered him a chocolate bread, gave him his computer back and wished him a good return to home.

Stéphane notes that he warmly thanks the entire medical team

His buddy picks him up in Geneva at 2:00 p. m. to drive him home.

The question: what is this unexplained diving accident?

On Monday, Stéphane stays warm at home to analyze from every angle what could have happened. Without an answer to his questions.

The next day, he went to pick up his vehicle and all his equipment that was blocked at his buddy’s house. Indeed, in Switzerland, the Police seal all the equipment for the purpose of a possible investigation by the prosecutor.

Following the intervention of the Police  and their call with Mr. Prosecutor, it was decided that no investigation would be opened. This is because all parameters have been respected and no hardware malfunctions are involved.

Having done a complete check-up with an ENT, it turns out that Stéphane has no lesions of the inner ear. Similarly, it is tested negative for the patent foramen ovale.

As a preservation measure, the hyperbaric service of the CHUV of Lausanne prescribes him 2 months without diving.

Stéphane will never know what put him in this state. An inner ear problem yes… But why and how?

Stephane Egger juste avant l'accident de plongée immérité
Stephane en plongée au lac | © Stephane Egger

Some possible explanations for the unexplained diving accident.

After a month of filmin his mind  “front back and back before pause play slow down etc”…. something comes back to him. Just before he came out of the water, he put his head back underwater to blow his nose 2 or 3 times and quite hard. Could this have caused the unexplained diving accident? Or a yo-yo done the Thursday before as part of a training session? Or a little bit of everything?

Anyway, Stéphane specifies that, when he dives with his buddies, they never leave each other for at least 1 hour they spent discussing everything and nothing special. This is a wise habit because otherwise, he would have found himself on the highway at 120 km/h at the time of the problem. Stéphane also realizes the safety of two-person diving and would not want to test solo diving.

Profile of the dive

- 55 minutes
- Minimum temperature 6 degrees / average temperature 6.7 degrees / air temperature 9 degrees
- Max depth 41.8 meters 3 minutes / average depth 18.1 meters
- Initial tank pressure 214.29 Bar / End of dive tank pressure 98.6 Bar / consumption 0.76 Bar per minute (normal for me).
- 7 minutes and 50 seconds to descend to 41.80.
- Safety stop of 3 minutes at 3 meters.
Des rayons de soleil traversant l'eau du lac de Genève
Ambiance aquatique du lac de Genève | © Stephane Egger

What can we learn from Stéphane’s experience?

  • There are diving accidents called undeserved and unexplained for which the cause is not necessarily found.
  • Complying with all safety rules does not guarantee an absence of diving accidents (but reduces the risks)
  • Taking time off with your buddies after the dive allows a good time but is also can accelerate the reaction to a diving accident.
  • Calling for help quickly is always a good idea.
Explanable or undeserved diving accident, an accident remains a traumatic event that can leave sequelae. We only have one life, think about it.

How do you feel about unexplained diving accidents?

Post a comment below to share your opinion and experiences with the entire passionate community.

And above all… don’t forget to be happy 🤗

Hélène

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  1. Hi, Your blog contains lots of information about diving accident. I am planning to do scuba diving this upcoming vacations. Keep sharing such an informative blog.

  2. I experienced an, so called, “undeserved hit” divine Zenobia wreck in Ciprus. I spent dive time of 43′ out of which abt. 5’+12′ at any 22m and 10′ at any 31′ on ean 28, 2nd dive after 2:40 hrs s.i.
    My computer was set on personal factor 0, most liberal.
    I stayed inside NDL but to its very maximum. Theoretical, I follow all the rules but after 3 hrs after surfacing I developed skin DCS (only) and ended up to the chamber for USN tabels 6, 5 and 9.
    After that I gave a lot of thoughts and I realised that there are no “undeserved hits”. I think that even my computer showed inside NDL I was actually ” in deco” and should add few deco stops. Should ask an ean 32. Should dive more conservative ( I think that if you stretch to the maximum to NDL you should consider yourself over it, “in deco”). Should set computer to a more conservative step.
    Should plan the dive better, eventually looking on the dive tables, too. Should consider factors like cold, hot, fatigue, currents, working load expressed on increased breathing or heart pulse, altitude, hydration, age physical condition etc.
    Ultimately, I think diving to the maximum of your computer NDL limits must be an exception and not a habit. Mentality should be changed from “I’m safe if my computer says so” in ” There is no guarantee of avoiding DCS even within the limits of computer or tables NDL”.

    1. Hello Razvan

      Thanks for your message, sharing information will surely help other people.
      Even with a computer, staying borderline can be dangerous.
      Undeserved is may be not the correct word, we should use unexplained. Nobody deserves a DCS !
      Very often in the instruction manual of a computer you can read that even if you respect everything you might get a DCS.
      Stay on the safe side

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