A British yachtsman has climbed to the top of his 60-foot boat, which is the height of a 10-storey building, while it sails through the waves.
Alex Thomson, from Titchfield in Hampshire has established himself as a daredevil in the sport of sailing.
After safely returning to dry land, Thomson said: "We have been planning this trick for a very long time. There were lots of things that could have gone terribly wrong:
The wind could have pulled me off the mast and catapulted me onto the deck; I could have hit the water at the wrong angle or surfaced too quickly.
Luckily (and despite my fear of heights), we succeeded in pulling it off. And as things turned out, the stunt was far more dangerous than I would ever have imagined. All in all, I can honestly say that it was the most stupid thing I’ve ever done in my whole life!”