It takes place at Henley-on-Thames on Sunday 12 July. Registration costs £25 and the minimum sponsorship target is £175. Adults can choose from two distances with a number of competitive and non-competitive categories. So whether you’re an experienced open water swimmer or new to swimming, this is the perfect challenge for you. Kids (aged 8 to 14) can choose from three distances: the Henley Half Mile, the Henley Quarter or the Henley Splash (200m).