An "extremely experienced" diver died on holiday in Micronesia after struggling with his equipment on the surface and plummeting 60 metres to the ocean floor without his breathing apparatus on, an inquest heard.
David Ring, from Totnes, Devon, was part of a group exploring Chuuk, or Truk, Lagoon, which is strewn with the wrecks of hundreds of Second World War planes and ships, when he died on October 13 last year, Plymouth Coroner's Court heard.
The 48-year-old had been staying at the Truk Blue Lagoon Resort when on the third day of their stay his group went to dive the wreck of the San Francisco Maru, a Japanese passenger and cargo ship.
In a statement read to the inquest, Mr Ring's dive buddy David Tobin said they entered the water after the rest of the group and he noticed Mr Ring was having trouble clipping his equipment on.
He said: "I thought he was going to ask me to help clip the second back-up cylinder on ... when I looked back he no longer had the breathing loop in his mouth.
"I then realised he was not moving at all.
"His arms were straight out in a cross shape."
Mr Tobin said Mr Ring began to sink and he descended after him "as quickly as I safely could".
The inquest heard he attracted the attention of dive organiser and instructor Mark Culwick and they found Mr Ring lying on his back on the ocean floor, around 6m from the port side of the wreck.
Mr Tobin said the breathing loop still was not in his mouth and he was "completely motionless".
Giving evidence Mr Culwick told Coroner Ian Arrow that six of the divers including Mr Ring had been using rebreathing equipment, which absorbs carbon dioxide and allows divers to stay underwater longer.
He said of Mr Ring: "I have done 2,500 dives and he had done more than me and he had been deeper too ... I really, really liked him.
"He was an easy, personable guy to get on with."
The inquest heard the group recovered Mr Ring's body and he was taken to hospital where he was formally pronounced dead.
Commenting on what might have happened, Mr Culwick said his opinion, given Mr Ring's "confusion" on the surface and his inability to clip his equipment on, was that he had a "significant medical event or succumbed to carbon dioxide poisoning".
Dr Paul Malcolm, a histopathologist at Derriford Hospital, Plymouth, said he "favoured" the occurrence of a medical event but "can't go further because he has had no post-mortem".
Fellow diver Mark Robinson, who said he was envious when Mr Ring booked the holiday as Truk was considered a mecca for divers, said his friend was a meticulous, careful and "extremely experienced diver".
"David always had the right attitude to diving," he said.
"His diving decisions were made with his head rather than his heart."
Recording an open conclusion, Mr Arrow said he could not be certain of Mr Ring's precise cause of death.
He said: "It appears to me on the balance of probabilities that he had some medical event that has overtaken him just as he was about to start to dive.
"I gather that from the evidence that he was unable to complete a simple task."
Mr Arrow added: "He died while he was on holiday doing what he loved best ... clearly from what I have heard David really enjoyed his diving and I am so sad that his death occurred at this time."
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