“I can remember pulling the last bits of air from the tank on my back,” says Lemons. “It takes more effort to suck the gas down. It felt a bit like the moments before you fall asleep. It wasn’t unpleasant, but I can remember feeling angry and apologising a lot to my fiancée Morag. I was angry about the damage this was going to do to other people. Then there was nothing.”

It took around 30 minutes before the crew of the Bibby Topaz were able to regain control and restart the failed dynamic positioning system. When Youasa reached Lemons on top of the underwater structure, his body was still.

Through sheer will, Youasa dragged his fallen colleague back to the bell and passed him up to Allcock. When they removed his helmet, Lemons was blue and not breathing. Instinctively, Allcock gave him two breaths of mouth to mouth resuscitation.

Miraculously, Lemons gasped back into consciousness.