Five Italian divers die in Maldivian cave; investigation underway

Maldivian authorities are investigating multiple possible factors behind the deaths of five Italian divers in a deepwater cave last week, including whether they descended far deeper than expected.

The group that entered the cave on Thursday was led by Monica Montefalcone, 51, a University of Genoa professor and marine ecologist who was a regular diver in Maldivian waters in the Indian Ocean.

Her daughter was among the four researchers who died, along with an instructor.

It is the deadliest single incident in the country's diving history.

Mohamed Hussain Shareef, chief spokesperson at the Maldives president’s office, told Reuters the government had given the group the necessary permit to research soft corals in the Devana Kandu site.

"Because, as divers will tell you and appreciate, it's a very different discipline with its own sets of challenges and risks involved, and particularly at that depth, there are any number of things that could have gone wrong."

Ms Montefalcone's husband Carlo Sommacal said in interviews to Italian media that his wife would have never put her daughter or others at risk.

He described her as "one of the best divers in the world" who had carried out about 5,000 dives and was "always conscientious" and "never reckless".

"I'm sorry, I wasn't there and I'm no expert, and from what I'm seeing and reading, even the experts don't have definite answers but are merely making hypotheses — lots of them," he told Reuters in a WhatsApp message.

On Monday, local time, Finnish divers recovered the bodies of two of the divers.

The body of the diving instructor was found outside the cave on the day they were reported missing.

'Very risky' dive, expert says

The non-profit Divers Alert Network Europe, which is leading the mission, said its expert divers had to use advanced technical systems, including closed-circuit re-breathers that recycle exhaled breathing gas to locate the bodies on Monday.

Shafraz Naeem, a Maldivian diving veteran who has explored the Devana Kandu cave system over 30 times on a deep-exploration permit and now consults with the country's defence forces and police, said the entrance to the cave is about 55 metres deep and light reaches only the first chamber and it is pitch dark after that.

"Theoretically oxygen toxicity starts to occur on compressed air at about 55 metres. That is very risky and very dangerous. You never know when oxygen toxicity will hit you."

The deeper a diver goes, the higher the pressure around them rises, which means each breath delivers more oxygen into the lungs and bloodstream.

If this exposure is too high or lasts too long, oxygen can begin to over-stimulate the central nervous system and damage tissues.

But Riccardo Gambacorta, former diving instructor of one of the victims, Muriel Oddenino, said he did not believe that the Italians died because of oxygen intoxication.

"My personal opinion is that an unexpected incident may have occurred underwater,"

"They essentially did not anticipate a certain situation."

Correct permits?

The group of Italians who entered the caves on Thursday included Ms Montefalcone's daughter Giorgia Sommacal, biologist Federico Gualtieri, researcher Ms Oddenino, and diving instructor Gianluca Benedetti.

Mr Shareef, chief spokesperson at the Maldives president’s office, said they have suspended the operation of the boat used by the divers "because the regulations here say that if you want to take divers on expeditions, you need a dive school permit, which they didn't have, sadly".

The boat operator of the MV Duke of York, Abdul Muhsin Moosa, said the vessel did have permission for recreational depth of up to 30 metres.

"We are sharing these details with the government, as well," he said, adding that the divers were briefed on arrival at the boat about Maldives' recreational diving limits and that they are not allowed to go beyond 30 metres.

For recreational dives up to 30 metres, normal air is compressed with 21 per cent oxygen and 79 per cent nitrogen, but for deeper dives the oxygen content has to be above 32 per cent, experts said.

For depths reaching at least 50 metres, divers are recommended to use at least two cylinders of specialised air each, they said.

It was not immediately clear if strong currents had any role in pushing the divers below those depths.