Let’s embark on an epic open water swimming adventure! The challenge? Swimming a whopping 20km in the glorious waters of Denham. You get to set the rules! Wetsuit or no wetsuit? It's your call!! Front crawl, breaststroke, butterfly, backstroke – mix it up.  You have from 1 April to 30 September to complete the swims. Grab your swim cap, channel your inner mermaid or merman, and let's make some waves! Make sure the challenge is tackled with laughter and loads of fun.