I followed him in the safety of a RIB boat, watching a tiny figure in a vast seascape.
Over the next 50 days he will swim 350 miles along the length of the English Channel, the world’s busiest shipping lane.
Don’t underestimate the jeopardy.
As he rounded Land’s End, the very tip of Cornwall, he was buffeted by converging currents.
“It’s like a washing machine underneath me,” he shouted.
According to Channel Swimming Association rules he can only wear a hat and Speedo trunks. It is little protection against the jellyfish.
“I put my hand on top of one and scooped it on to my groin. It hurts, ” he said.
He will need grit for what he calls the Everest of swims.
He’s on his own in the water for several hours at a time, isolated from his support team.
When the going gets tough he focuses on his next 10 strokes and makes them as good as they can be. Then the next, and the next, until his mind is in a better place.
But he can’t fight nature.
When the tide turned he began to be pushed backwards. Time for a break.
With his GPS co-ordinates logged to mark the starting point of the next leg he climbed aboard his support boat.
“The water is 14.3 degrees”, he said, showing me the monitor on his wrist.
“It’s a lot colder than I expected.”
Hypothermia is a big risk at such low temperatures.
A long hot shower and then he took to his bed, huddled under a duvet.
He had to warm up quickly to get his body ready for his next swim when the tide turned again in a few hours time.
He’ll have to do that day after day, in all weathers.
After leg one he’s four miles down, with 346 to go. But it is progress and the long swim to Dover is now that little bit shorter.