The dive-buddy of a woman who died on an error-strewn Gozo shore-dive in early 2020 has been found guilty of involuntary homicide through negligence.
Maltese company director Arthur Castillo, 60, had been diving with an old friend, ex-British Army soldier Christine Gauci. The death of the 35-year-old while diving at Mgarr ix-Xini on the morning of 18 January was reported on Divernet, which stated at the time that an unnamed dive-buddy had raised the alarm when she failed to surface.
In Gozo Court of Magistrates proceedings reported by Malta Today, Magistrate Simone Grech heard that the two were part of a group of six friends who had met for a planned dive at the south-coast bay site. When Gauci had told Castillo that she had been awake for 20 hours because of work, his girlfriend had tried to dissuade her from diving.
Gauci had been a member of the Armed Forces of Malta (AFM) since 2005, but had taken four years out with the British Army, specialising in air defence and undertaking a tour of duty in Afghanistan in 2011.
Back in Malta she had served with the AFM company responsible for security at the international airport, and had expressed an ambition to work in underwater bomb-disposal. She was described in court as a diving instructor and also a freediver.
Open-circuit and CCR
Gauci, equipped with two open-circuit air tanks and wearing what was described as an oversized drysuit, had entered the sea with Castillo, who was using a closed-circuit rebreather. Soon after going under water and at a depth of 16-18m Castillo had helped Gauci, who was untrained in drysuit use, with a buoyancy problem.
He had suggested surfacing at this point but Gauci had signalled her wish to continue and they had descended to 28m. Gauci had again experienced buoyancy problems and Castillo had needed to hold her down and dump air from her BC.
After entering a small cave one of Gauci’s fins had become entangled in netting, and Castillo had helped to cut her free. She had again signalled that she wanted to continue and he had led them shallower to 15m, heading back towards shore.

When Gauci’s buoyancy problems occurred for a third time, Castillo had transferred two 1kg weights from his belt to hers, and also passed her a heavy rock to hold. Gauci had again signalled her intention to continue the dive but Castillo stated that while he was turned away from her she had suddenly shot up before he could reach her. He had seen the rock fall past him.
Joined the other divers at 8m, Castillo stated that he had been unable to follow Gauci straight to the surface because he needed to decompress. However, experts who later checked his dive-computer attested that a two-minute deco obligation at 5m was “never an impediment to seek a lost diving buddy”.
Tank was empty
Once at the surface Castillo thought he had seen Gauci, but after swimming in that direction realised that it was another diver. He and other divers eventually found her face-down in the water near the rocky shore, her eyes rolled back and foam in her mouth.
In attempting to inflate her drysuit they found that her twin-set was empty, though she also had a nitrox 50 decompression cylinder which had been untouched.
Expert witnesses reported that Gauci had not only been fatigued but that the ill-fitting drysuit was trapping too much air and was also defective. Her air-fill was said to have been supplied by an unlicensed operator using a compressor with “questionable maintenance”.
A hyperbaric doctor added that Gauci’s dive-computer, adjusted to its most aggressive setting, expressed “the diver’s general demeanour towards risk-taking”.
The experts expressed the view that Gauci might have suffered a cardiac arrhythmia causing shortness of breath and leading her to make an instinctive rapid ascent.
Lost eye contact
The court concluded that Castillo had played his part as a dive-buddy until the later stages of the dive, by which time he had stopped checking Gauci’s air supply despite knowing that her consumption had been rapid.
Twenty minutes into the dive she was down from 200 to 130 bar, but he had last checked 25 minutes before the final incident, when she had 110 bar left. The court noted that as a CCR diver unconcerned about his own gas supply, issues with his buddy’s were not uppermost in Castillo’s mind.
Castillo had lost eye contact with Gauci and then, despite her sudden ascent, had assumed that she had surfaced safely, leading the magistrate to describe his failure to attempt a rescue as negligent and a contributory factor in Gauci’s death. It could easily have been avoided had he “exercised the caution and prudence evidently needed in the circumstances”, said Grech.
Contributory negligence on Gauci’s part did not exonerate Castillo of criminal responsibility, she said, sentencing him to two years in prison suspended for four years, and ordering him to pay two-thirds of the costs of appointing expert witnesses.
UPDATE: Dive-Pros Flag Up Failings In Malta Homicide Verdict
Also read: Tech diver slams court-expert ’flights of fancy’
Body had drifted 300 miles
DNA from a drysuit-clad body recovered from the sea off Norway has allowed it to be identified as that of a British diver in his 60s who went missing off the Farne Islands, Northumberland on 17 October, 2021.
The unnamed man had failed to surface from a boat-dive near Longstone Lighthouse, sparking a major 48-hour search, and his body was found eight months later and more than 300 nautical miles away near Lindesnes Lighthouse on 5 June.
Also on Divernet: Malta Dive-Pro Cleared Of Manslaughter, Instructor Cleared Over Malta Diver Death, British Diver Dies In Malta
Very discouraging to read these stories about dive professionals not acting professional.
There were no dive professionals involved. The victim was a soilder who served in Afghanistan, and a technically trained dive instructor herself.