Lewis Pugh, the UN Patron of the Oceans and renowned endurance swimmer, will complete the final leg of his Seven Seas Campaign by swimming up the Thames.
Nicknamed the Human Polar Bear for his ability to swim long distances in freezing waters, Lewis is swimming from Southend to Gravesend before swimming to the Thames Barrier.
He's the first man to swim at the North Pole and over the last four weeks has completed swims in each of the Seven Seas, the Mediterranean, Adriatic, Aegean, Black, Red, Arabian and the North Sea.
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The unlicensed events unfolded on Saturday night at Clapham Common and Tooting Bec Common.
A 37 year old man who was taken to hospital after getting into difficulty in a stretch of water near Maidenhead has died.
Jonty Bravery, who is mentally ill, has been jailed for 15 years after throwing a six year old boy from the Tate modern balcony.