Dr Vincent Hong and Tim Saville: 'Unanswered questions' over deaths of experienced divers on Greek deep-diving trip

Prof Paul Marks was speaking at the inquest in Hull into the deaths of Huddersfield businessman Tim Saville, 61, and Consultant Cardio-thoracic Anaesthetist Dr Vincent Hong.

Dr Hong, who worked at hospitals in Hull, died on September 27 2019 during a dive on the wreck of SS Burdigala, a liner sunk by a U-boat off the Greek island of Kea in 1916.

Mr Saville, who had made hundreds of dives and had been using a rebreather for over 15 years, died during a dive on the wreck of the Titanic's sister ship HMHS Britannic two days later.

His widow Liz described him as "very charismatic, nobody ever forgot him", adding: "He left a big hole in a lot of people's lives".

Keen diver Dr Hong "was just full of energy and loved life," his widow Lily said.

A number of different theories were advanced as to how the men died. They'd trained for two years for the Greek trip, and Dr Hong had dived to 104m just the month before.

Dr Hong, who the court heard was "festooned with equipment" including a scooter, descended to 63m, explored the wreck and took photos. But halfway through his ascent some of the gear became entangled with the shotline.

The court heard that another diver realised he had a problem and noticed he was trying to ascend with the help of his scooter.

He approached and untangled him and signalled to ask if he was OK. "Mr Hong did not respond and the mouthpiece left his mouth", the inquest heard. An attempt to give him bail out gas was not possible.

The court's independent expert, consultant cardiologist Dr Mark Turner, a past chairman of the UK Diving Medical Committee, said: “We know he was an experienced diver for him to be taking such extreme measures he must have realised there was a problem and he was trying to solve it. I can’t really tell you what the problem is.”

After the tragic events of Dr Hong's death, some of the group didn't want to continue, but others did, but emphasised the need for safety.

Everyone seemed "calm and composed" and weather conditions were "exceptionally benign". They explored the wreck using scooters, with Mr Saville slightly above and behind.

Between nine and 12 minutes into the 116m dive Mr Saville appeared to stop, and was kneeling on a piece of super structure.

"It became immediately apparent it was not a small issue," a statement from one of the divers read to the court said. "His breathing loop was no longer in his mouth".

There was a red light on his display and despite attempts to revive him with emergency gas, he was "completely unresponsive". After there had been no response for several minutes his equipment was buoyant and he drifted upwards, with the other divers having to remain at depth and complete two hours of decompression. He was given CPR on the surface.

Dr Turner advanced three “plausible explanations” about the death of Mr Saville, who was co-director at Bronte Water Coolers, based at Honley.

He said it was "pretty unlikely" that carbon monoxide was to blame, either from exposure on the boat or in the divers' cylinders, as other divers using the same gas didn't have symptoms.

But he said he didn't have an alternative explanation as to why a second post mortem carried out in the UK, following one done in Greece, found evidence of carboxyhemoglobin (formed when hemoglobin is exposed to carbon monoxide) in both of the bodies. Both men were non smokers.

Criminal investigations continue in Greece. Prof Marks reserved his conclusion till a later date.

He told the families: “Although we have gone into a lot of detail, unfortunately we are not going to know precisely what these events were.”

Mrs Saville said the hearing had left “a lot of unanswered questions”.