An Aussie dive instructor has weighed in on the mysterious deaths of five Italian scuba divers in the Maldives after one enthusiast sensationally claimed the group were “dead the moment they went in” the water.The group failed to resurface after diving 48 metres – 150 feet – into a cave in the waters of Vaavu Atoll on Thursday. Two of the five were said to be experienced divers.A rescue diver also died during an operation to recover their bodies on Friday.Cathy Johnson from the Australian Underwater Federation, Australia’s diving accreditation body, said it was “unusual” for recreational divers to go to that depth in this country.“There is very limited information about the skill level or training of the divers but to dive to that depth in Australia you require advanced technical diver training,” Ms Johnson, who has been an instructor since 1984, told news.com.au.“However, in the Maldives, I have friends who have worked there and have had an experience where they’ve been required to take recreational divers down to 70 metres, which is very dangerous, in my view.“Why did they plan to go into a deep cave, which is a very skilled area, when it appears they did not have cave diving experience and the proper equipment? I don’t know why they’d even think of doing that on what seems like an ordinary charter trip.”‘Dead the moment they went in’It comes after US hobby diver Marc Randazza set social media ablaze when he claimed the deaths were “either group suicide or murder”.In post on X, the self-described deep-sea diver wrote: “I’ve been diving for 30 years. Rescue and deep dive certified. These divers were effectively dead the moment they went in the water. “At 150 feet, with recreational gear and without a special gas mix, you’re already dead.”Mr Randazza said there was “no possible way” the divers would have survived those depths “whether they panicked or not”.“That dive plan was never going to end with any of them alive,” he added. Nitrogen narcosis ‘euphoria’ could have impacted group Ms Johnson said it’s not clear if the group were set up for a deep dive, which typically requires planning. She also said in Australia, cave divers need to be trained and qualified before going out.Ms Johnson, who is the Recreational Diving Technical Officer for the AUF, said it’s likely the divers ran out of air after becoming disorientated inside the cave.“Nitrogen narcosis affects divers at depth if they are diving on air, which occurs when the levels of nitrogen go up in your blood system. You get a type of euphoria, which is a bit like a feeling of being drunk and people don’t do what they would normally do. They might forget what to do in an emergency, or they might think it’s funny,” she said.Ms Johnson added divers can also experience decompression sickness, which is caused by nitrogen forming bubbles in muscle tissue or blood when emerging too quickly after being at depth. “This is reportedly what happened to one of the recovery divers. The reports state that oxygen toxicity may also be to blame. All these depended on what gas mixture they were using. The most likely scenario is they ran out of air after becoming disorientated inside the cave,” she said.‘Something must have happened’On Friday, Mohamed Mahudhee, a member of the Maldivian national defence force, suffered decompression sickness while diving in a search for the remaining bodies on Friday.He died of the sickness after being transferred to hospital.“The death goes to show the difficulty of the mission,” Mohamed Hussain Shareef, the Maldives presidential spokesperson, told reporters.The group of Italians included Monica Montefalcone, a marine biology professor at the University of Genoa, and her 20-year-old daughter, Giorgia Sommacal.Three other adventure seekers on the trip — Muriel Oddenino of Turin, Gianluca Benedetti of Padua, and Federico Gualtieri of Borgomanero — also drowned during the dive.Mr Benedetti’s body was found near the mouth of the cave shortly after the incident, while rescuers believe the remaining four divers are inside the same cave, which consists of three large chambers connected by narrow passages.Carlo Sommacal, Ms Montefalcone’s husband and Giorgia’s father, said that “something must have happened down there”, given his wife and daughter’s extensive experience.Speaking to Italian TV, he described Ms Montefalcone as a highly disciplined and careful diver.Oxygen toxicity and sheer panic Experts have said oxygen toxicity and sheer panic are also possible factors behind the deaths of the five scuba divers.“It’s likely that something went wrong with the tanks,” Pulmonologist Claudio Micheletto told the Italian outlet Adnkronos on Thursday.Diving at 50 metres exceeds the maximum depth recommended for recreational divers by most scuba certifying agencies, with depths beyond 40 metres considered technical diving that requires special equipment.The Italians were diving from a 36-metre luxury yacht, the Duke of York, when they disappeared.A sixth diver, a student at University of Genoa, had been geared up to dive when she changed her mind and stayed on board, becoming the trip’s sole survivor.The yacht’s operating license has been suspended pending an investigation, according to the Maldives Tourism Ministry.