A diver died in Dorset when his dry suit's inflator button was accidentally pressed, sending him rocketing to the surface, an inquest has heard.
Nigel Foster, 46, from Croxley Green, Hertfordshire, was collecting scallops from the seabed 20ft (6.1m) down off the coast of Portland on 28 June.
He was bringing two bags back to the surface when they pressed against his inflator button.
A verdict of accidental death was recorded at the inquest on Wednesday.
It was heard that Mr Foster's diving buddy Colin Alexander found a cannon ball and sent it to the surface in an inflatable bag but when Mr Foster found a second one he decided to keep it with him during the dive.
On the way up, the weight of the bags pressed an inflator button on his chest causing the suit to fill with air and send him to the surface "like a rocket" in about five seconds, West Dorset Coroner's Court heard.
Mr Alexander told the inquest: "I just looked up to see if I could see the surface but I saw Nigel at the surface looking down at me which shocked me.
"From what I perceived he was just looking down at me looking bewildered as if 'how did I get up here'."
The dive boat skipper and other divers cut free the bags and dragged him on to the boat to start CPR until help arrived.
But Mr Foster was declared dead on arrival at Dorset County Hospital in Dorchester.
A post-mortem examination showed he died from diffuse gas embolism due to pulmonary barotrauma - the expansion of gas in his lungs.
Coroner Michael Johnston said: "Nigel Foster probably lost control of his inflation suit when the bags pressed on it and surfaced at speed.
"Because he was concentrating on trying to deal with the situation and because he must have been disorientated when this happened, he didn't breathe out and he suffered the damage to his lungs which I suspect caused his death almost instantly."