British diver Robert Fox, who died diving in the Red Sea in January, suffered a heart attack that could have been triggered by helping a buddy.
A coroner said the heart attack could have been triggered by the stress of the incident.
Fox, 43, of Malvern, was one of four divers accompanied by a guide who were diving on the wreck of the El Arish El Tor near Safaga. Fox's buddy, Mick O'Brien, had too much weight on and descended quickly to 35m, Worcestershire Coroner's Court heard.
Fox, a PADI Divemaster, went to assist him and gave O'Brien his alternate air source. O'Brien then made a rapid ascent, surfacing some distance from the dive boat.
The dive guide and other divers were concerned O'Brien could be suffering from decompression illness. The assistant deputy coroner Victor Round said it was 'quite a long time' before anyone noticed Fox was missing.
Bad weather hampered the rescue operation and Fox's body was found four days later near where he was last seen, by the anchor of the wreck. His kit was intact and his mask was still on his face.
Dr Lyndsae Wheen, a pathologist specialising in diving matters, told the inquest Fox died after a blood clot triggered an irregular heart beat. The coroner said: 'A stressful incident can trigger the movement of a plaque like this. It can only be speculation, but going to the aid of a buddy in distress while diving may be that stressful incident.'
