By Lex Harvey, Anna Chernova, CNN
(CNN) — Deep beneath the crystal turquoise water, white sandy beaches and thatched overwater bungalows of the Maldives lies a deep and narrow system of caves, devoid of light and the colorful marine life that inhabits higher waters.
The seas were rough and the wind was picking up late Thursday morning when a team of five experienced Italian divers plunged toward these pitch-black caverns off the Vaavu Atoll, about an hour south by speedboat of the capital Malé.
The group included instructor Gianluca Benedetti; Monica Montefalcone, an associate professor of ecology at the University of Genoa; her daughter Giorgia Sommacal; marine biologist Federico Gualtieri; and researcher Muriel Oddenino.
The divers ventured deep into the cave network, which opens at a depth of about 47 meters (154 feet) and drops to about 70 meters (230 feet) at its lowest point.
They never returned.
The bodies of the five scuba divers were only found after a multi-day search effort, a fraught and perilous process which claimed a sixth victim, local military diver Sgt. Mohamed Mahudhee.
The group had permission to dive deeper than the 30 meters (98 feet) Maldivian recreational dive limits allow, local authorities said.
But it’s not clear whether they went deeper than planned, or whether they had the appropriate equipment for such a high-risk expedition.
A frantic search
The divers were staying on board a luxury 36-meter yacht called the Duke of York that offers customized cruises for up to 25 guests.
An ocean lover’s dream, the yacht allows divers to explore the Maldives’ coral islands up close, while enjoying seafood dinners and days spent lounging on sun beds on the top deck.
Around 1:30 p.m. Thursday, someone aboard the boat put out a distress signal, Mohamed Hussain Shareef, the chief spokesperson for the Maldives government told CNN.
The divers had been underwater for about two hours and had failed to resurface.
Another liveaboard vessel responded first, Shareef said. Within about half an hour, divers from that vessel located Benedetti’s body at the mouth of the cave.
The Maldives Coast Guard began an over and underwater search for the four remaining divers, but once Benedetti’s body was found, the authorities began working under the assumption that the four remaining divers were inside the cave.
Monica Montefalcone was an environmentalist who had conducted marine research in the Maldives for many years.
Her husband Carlo Sommacal, Giorgia’s father, said his wife was “one of the best divers on the face of the earth.”
“She must have completed 5,000 dives,” Sommacal told Italian newspaper la Repubblica.
Ahead of the dive, the Maldives’ Marine Research Center had approved a research proposal from Montefalcone, Gualtieri and Oddenino to study soft corals near the Vaavu Atoll, Shareef said. Sommacal and Benedetti were not listed on the application.
The Italian researchers had also obtained permission to conduct technical dives, meaning they could explore deeper than 30 meters, Shareef said.
But the Maldives authorities did not know the divers would be cave diving, Shareef said, or they would have lent the support of the Coast Guard or other professionals to assist with the complex dive.
“We are very sure that we would have been able to give them much clearer guidelines and advice had they told us that this was such a demanding assignment at such depths inside a cave.”
The University of Genoa said Montefalcone and Oddenino were in the Maldives