Diver's horrifying death after stabbing himself in heart while lost in underwater labyrinth

The untamed beauty of Croatia's Adriatic Sea is a haven for divers, swimmers and fishermen. The island of Šolta, which has a small population of only 1,700, boasts secluded coves including the rarely visited bay Poganica.

The bay, which features a cave, is encased in mystery including legends of pirates and mythical sea monsters and locals often give the area a wide birth.

Poganica Cave became infamous for a harrowing tragedy in September 2002 when a diver died as he explored the depths of the underwater cavern.

The man, identified only as M.K. was one of several divers off the back of a sailing trip who entered the water on Tuesday, September 10 but he would never resurface.

He entered the water after a night of fun at around 9.15pm with a 15-liter air cylinder and a dive computer.

M.K. descended slowly, the cave entrance beckoned to the diver at nine meters (29.5 ft). The Bay of Poganica Cave lay open, a two-meter wide funnel gradually swallowing light into its dark belly. At 15 meters of depth, it forked out into two labyrinths – one shallow, the other a treacherous plunge into the depths.

M.K., oblivious to the danger, chose the latter, the deep gallery descent which dropped down 57-meters. Unknown to the diver, the cave wasn't a normal underwater tunnel with fine silt lining the walls. This could turn the crystal-clear water into a dirty mess if stirred by careless fins.

If the silt was disturbed, the murky after effect saw powerful flashlights prove so useless even your own hands couldn't be seen a foot away from your face.

Time became a silent enemy for the diver as what started as a carefree dive saw the clock tick by and soon he had used almost half of his tank's air, which contained a total for one hour of diving.

This meant he barely had enough for a safe ascent, let alone the decompression stops crucial to avoid the agonizing bends. The darkness and an impaired judgment fuelled by the evening's drinks proved to be a lethal cocktail for M.K. The diver continued on, oblivious to the growing panic that would soon grip those on the surface.

According to Cave Diving Accident, at around 10.30pm, over an hour since M.K. entered the water, his friends started to get worried. Two of the divers frantically explored the cave's belly but the vast labyrinth revealed no clues. By 11.41pm, long after M.K.'s air had run out, they was very worried.

An emergency call reached the authorities in Split who sent two police divers at dawn, equipped and determined to locate the wayward diver. The pair entered the water to search for M.K. but their dive would also end in tragedy as one of the officers vanished into the deep chasm and drowned. The other policeman managed to get to the surface and broke the water gasping for air.

Driven by a sombre resolve, a team of divers re-entered the labyrinth where they relocated the body of the missing police diver at around 24 meters.

They continued down to the 54 meter mark where they discovered M.K. still in his gear but with disturbing details painting a grim picture.

His regulator was ripped from his mouth, his mask lay abandoned but most disturbingly, a knife was lodged in his chest. The police initially treated the situation as a crime scene and considered homicide as a potential cause of death.

A thorough investigation was conducted, which saw every piece of the diver's gear forensically scrutinised. Two crew members were arrested as the truth was sought, other people present when M.K. embarked on his fateful dive were denied the opportunity to leave the country until the investigation concluded.

M.K.'s dive computers revealed plenty of data thanks to a history of 37 prior dives. This treasure trove of information provided a glimpse into M.K.’s diving experience, potentially revealing his comfort level and level of expertise.

The autopsy results revealed an 11-centimeter stab wound had pierced his chest, puncturing his aorta. The water in his lungs confirmed the grim truth, that he had drowned, succumbing within minutes of the attack. The blood alcohol level added another layer of complexity. While exceeding the legal driving limit, it wasn’t necessarily incapacitating.

Investigators ruled out several possible scenarios including that he was murdered on the surface, the dive was a premediated murder that happened underwater or an ear injury.

Ultimately, police believed the death was caused by suicide. The forensic team’s reasoning for his suicide was that the diver found himself in a extremely dangerous situation. The fear of a drawn-out, agonizing death by drowning could, in a panicked state, make self-infliction appear preferable and logical.

The death of M.K., alongside the rescue diver, tragically validates the dangers of scuba diving and the challenging environment underwater of the Poganica Bay Cave.