He came into view under Lambeth Bridge, swimming into the teeth of a 30mph head wind, a tiny white dot dwarfed by the slate grey expanse of the river Thames running at full flow.
His supporters assembled on Westminster Pier let out a roar. But for Lewis Gordon Pugh, a 36-year-old lawyer turned polar explorer, endurance swimmer and now environmental campaigner, coming ashore was to be none too easy.
First he had to cut cross the six-knot tide, tough for even the strongest swimmer, making a diagonal tack into the slamming waves. Then he had to pick his way through the scrum of cameras that had come to record the 17th day of his attempt to become the first person to swim the 203-mile length of the Thames.
Already delayed by unprecedentedly low water levels, the hottest July ever and the unwanted attentions of the occasional over-inquisitive swan, the last hours had been the toughest of his life, he conceded.
"These conditions remind me of swimming around the Cape of Good Hope or southern Australia," said a "physically and mentally shattered" Mr Pugh.
But rest would have to wait. He climbed the steps, flanked by WWF campaigners dressed as polar bears, and prepared for yet another round of media interviews before hand-delivering to Downing Street a letter to Tony Blair urging him to reduce UK carbon emissions by 20 per cent by 2010 and to make the battle against climate change the outgoing Prime Minister's "personal legacy".
Mr Pugh's swim along the Thames, which began with a 19-mile run along the bank until the water ran deep enough to allow him to get afloat, has seen him complete a gruelling 11 miles each day. But his efforts to publicise looming environmental disaster have paid handsome dividends, generating massive international media attention. He says he first became aware of the effects of climate change while training and racing in the Arctic regions, where he holds world records for endurance swims. Today he is taking his duties as the new found symbol of the battle against global warming seriously.
"I'm stopping off at Downing Street to ask Tony Blair to urgently put climate change at the top of the agenda, by putting policies in place to ensure that we meet our national climate targets to reduce C02 emissions," he said.
Mr Blair had agreed to meet the swimmer personally - provided he had changed out of his Speedo swimming trunks. The two men spent several minutes chatting together before shaking hands for the cameras on the steps of No 10.
"I tried to encourage him to go to the Antarctic or the Arctic. There is no world leader who has been there, so far as I know," said Mr Pugh after the meeting, in what his host may relish as a welcome slight to David Cameron's environmental leadership credentials. The Tory leader's glacier visit earlier this year earned both plaudits and brickbats from both within his party and beyond.
"Not going to these regions is the equivalent of a world leader not having gone to Iraq," added Mr Pugh a little less diplomatically, raising the festering sore of the conflict that many of his opponents believe will be Mr Blair's true legacy.
The swimmer will resume his journey this morning, and expects to finish on Sunday when he will come ashore at the pier in Southend-on-Sea.Reuse content