Inquest Into Death of Belgian Diver in Donegal Reveals Final Moments on 83m Wreck Dive

An inquest into the death of Belgian technical diver Luk Heyvaert has shed new light on the final moments of a deep wreck dive off the coast of County Donegal, revealing a tragedy that unfolded despite experienced divers, functioning equipment, and rapid emergency response.

The hearing at Letterkenny Courthouse examined the events of July 22, 2024, when the 52-year-old diver lost his life during a planned expedition to the wreck of HMS Viknor, lying at a depth of approximately 83 metres. 

A Planned Technical Dive

Heyvaert was part of a well-prepared group of Belgian divers on a structured dive trip, bringing their own equipment and undertaking a series of wreck dives along the Donegal coast. The group had already successfully completed dives on HMS Audacious and SS Empire Heritage in the days leading up to the incident. 

The dive to HMS Viknor was always intended to be a demanding technical profile. The plan involved around 30 minutes at depth, followed by a long staged decompression lasting several hours, managed via rebreathers and dive computers. 

The Moment Things Changed

Evidence presented to the inquest described how the dive initially progressed normally. Divers reported a “nice, relaxed dive” at depth, with no early signs of difficulty.

The situation changed during ascent.

Fellow divers began to notice that Heyvaert appeared agitated and unsettled, pressing his wrist computer repeatedly and failing to respond to hand signals. 

At around 27 metres, a buddy attempted to provide him with back-up gas. What they saw was alarming.

“I saw fear in his eyes,” one diver told the inquest. 

Despite assistance, Heyvaert continued ascending in distress, bypassing planned stops and showing signs of escalating panic.

Rescue Efforts Underwater

As the situation deteriorated, more experienced divers moved in to assist, taking over efforts to stabilise and escort him safely to the surface.

By 12 metres, his condition had worsened significantly. He was described as frantic, pale, and unresponsive to support attempts. 

Moments later, he stopped breathing.

“At the 12m stop, Luk let go of his mouthpiece. I noticed a mouthpiece was shoved into his mouth. At some point he stopped breathing… there were no bubbles,” a diver recalled. 

Divers made the critical decision to use lifting gas to bring him to the surface, securing him to the shotline to prevent him from sinking and being lost.

It was a last attempt to save him.

Surface Response and Emergency Action

The first sign to the surface team that something was wrong came when multiple delayed surface marker buoys appeared, signalling distress and the need for additional gas.

The skipper descended, located the unconscious diver entangled near the safety stop, and brought him to the surface.

CPR was initiated immediately on board, alongside oxygen administration, while Malin Head Coast Guard coordinated an emergency helicopter evacuation. 

Despite sustained efforts, there were no signs of life.

What the Inquest Found

The inquest heard extensive evidence from divers, the vessel operator, medical experts, and post-mortem findings.

Key conclusions included:

• Cause of death: drowning
• Verdict: death by natural causes
• Likely contributing factor: immersion pulmonary oedema (IPO) 

IPO is a condition where fluid accumulates in the lungs during immersion, impairing breathing without the need to inhale water. While difficult to confirm definitively, expert testimony suggested it was the most plausible underlying trigger.

Crucially, the inquest found:

• No equipment malfunction
• No issues with gas supply or rebreather function
• No evidence of trauma or external injury

Technical diving expert David Gration told the court:

“Everything that seems to be going on is physiological.” 

A Key Uncertainty That Remains

Despite detailed testimony and analysis, the inquest could not definitively determine the exact initiating event.

Coroner Dr Denis McCauley acknowledged the limits of certainty:

“We have explored everything we can… there comes a point that we have to say we don’t know.” 

That uncertainty is not uncommon in diving fatalities, particularly those involving complex physiological responses at depth.

Contributing Factors Considered

The inquest explored several possible contributing elements:

• Rapid physiological stress during ascent
• Possible CO₂ concerns, though ruled out by dive computer data
• The effects of heavy hydration prior to the dive
• The potential onset of immersion pulmonary oedema

Experts noted that excessive fluid intake shortly before diving may increase IPO risk, recommending gradual hydration over 24–48 hours instead. 

“Everything Humanly Possible”

One of the clearest conclusions from the hearing was the response of those involved.

From underwater rescue attempts to surface CPR and emergency coordination, the actions of the dive team were described as exemplary.

“The people around Luk did everything humanly possible to help him.” 

For the diving community, that finding carries weight. It confirms that this was not a failure of training, planning, or response.

A Tragedy Without a Simple Cause

The death of Luk Heyvaert highlights a difficult reality in diving: even among experienced, well-equipped technical divers, not every incident has a clear or preventable cause.

The dive was planned.
The equipment worked.
The response was immediate.

And yet, the outcome could not be changed.

For divers, instructors, and operators, the case reinforces an uncomfortable but important truth. Some risks in diving are not mechanical or procedural, but physiological, unpredictable, and not always fully understood.