Maldives investigates if Italian divers went too deep in fatal cave dive

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, a government spokesperson told Reuters.

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. The instructor's body was the first to have been recovered, from a depth of 60 meters (200 feet).

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

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

"What we didn't know was that it was cave diving," Shareef said. "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."

Montefalcone's husband Carlo Sommacal said in interviews with 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.

Expert divers from Finland spotted the four remaining bodies on Monday inside the cave's third and last chamber, "pretty much together," Shareef said. Two of them were recovered on Tuesday and the other two were expected to be brought to the surface on Wednesday, he said.

Highlighting the difficulties of diving at that depth, a Maldivian rescuer died last week while attempting to recover the bodies. The non-profit Divers Alert Network Europe, which is leading the rescue mission, said its expert divers had to use advanced technical systems, including closed-circuit rebreathers that recycle exhaled breathing gas to locate the bodies.

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

Experts say that as a diver goes deeper, the pressure around them rises, which means each breath delivers more oxygen into the lungs and bloodstream, even if they are breathing normal air. If this exposure is too high or lasts too long, oxygen begins to over-stimulate the central nervous system and damage tissues.

"It is incredibly dangerous to conduct dives at these depths on compressed air," Naeem said. "Theoretically oxygen toxicity starts to occur on compressed air at about 55 meters."

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," he said.

Permits missing? 

The Italian group included Montefalcone's daughter Giorgia Sommacal, biologist Federico Gualtieri, researcher Oddenino, and diving instructor Gianluca Benedetti, who had lived in the Maldives for seven years.

Shareef 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 meters. He said the divers were briefed on arrival about the Maldives’ 30-meter recreational diving limit.

For recreational dives of up to 30 meters, normal compressed air containing about 21% oxygen and 79% nitrogen is used. To allow longer dives, or to reduce the surface interval between dives, recreational divers also use "nitrox" mixes containing 32% oxygen or above, said diver Naeem.

For much greater depths such as those reached by the Italian group, divers typically use specialised blends that include oxygen, nitrogen, and helium, known as Trimix, he said. Diving to such depths requires advanced training and specialist equipment.

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

The University of Genoa said Montefalcone and Oddenino were in the Maldives on a scientific research mission to monitor the marine environment and the effects of climate change on tropical biodiversity.

“The diving activity was not part of the mission’s planned activities, but was carried out on a personal basis,” it said in a statement, adding that Montefalcone's daughter and Gualtieri were not part of the scientific mission.