Serpentine Swimming Club members are hardy souls used to sub-zero skinny dips in the Hyde Park’s Serpentine Lake. They train all year for a festive swim in the annual Peter Pan cup donated by author JM Barrie and the club says “if the lake is frozen we break the ice and still swim”. But one of the mildest Christmas Days since records began melted their resolve with all expectations of a frozen pool and a brrrrrrrrrilliant contest. The water temperature was an unseasonal 4C in a race which Volker Koch won with 63 trailing in his wake. The Christmas Day fixture held since 1864 can only be entered by paid-up club members who compete every Saturday morning throughout the year, regardless of the weather.