The Mayor of London looked windswept but relaxed as he sped along the Thames on a motor boat before being winched aboard HMS Severn.
Mr Johnson admitted to having been rather nervous about the adventurous stunt, but said that, in the event, he had found it rather less stressful than expected: “If anything, in my view, the boat could have gone even faster.”
He was there to launch the largest-ever London Poppy Day which, he said, would be the perfect forum for the public to show their support and gratitude for “the amazing professionalism of our armed services”.