Diver survived 35 minutes – on 6 minutes of air

This compelling true story of a diver trapped on the bottom of the North Sea is to be shown on TV.

Chris Lemons’ body amazingly was able to survive for 35 minutes on a six-minute emergency air tank.

At the time of the incident Chris was relatively new to saturation diving. It was an exciting time in his life – he was engaged and building a dream house in the Highlands with fiancée Morag Martin.

On this rotation he would be working with his mentor Duncan Allcock and the very experienced diver, Dave Yuasa.

When the alarm sounded, Dave and Chris were carrying out routine maintenance on an oil-well 100m underwater, 115 miles east of Peterhead.

What they didn’t realise was that the positioning system on their dive support vessel had failed and it was now drifting out of control away from the dive site.

Dive supervisor Craig Frederick immediately instructed his divers to return to the safety of the bell.

As always Dave and Chris were attached to the bell and the vessel by their umbilicals — long intertwined cables and hoses that carry breathing gases, hot water to combat the frigid North Sea, power for the divers’ headlamps and communications to the ship.

As the dive support vessel drifted further away everything attached to the ship was dragged along with it. Everything except for Chris; his umbilical was snagged on the structure he and Dave were working on. As the full weight of the 8,000 tonne vessel strained against his lifeline, it started to stretch.

Through first-hand accounts, archive and black box footage and underwater reconstructions, Last Breath examines the full dramatic story.

Last Breath will be shown on BBC Scotland on Tuesday 7 May, from 10–11.30pm.