Given the cleaner shores in the UK, many more residents are swimming in British lakes, rivers, and seas as a hobby. This year, more than 20,000 registered for five events hosted by the Outdoor Swimming Society. Open-water swimming is also one of the few hobbies that can appeal to young people and retirees in equal measure. For more on this flourishing hobby, click here:: Different strokes: open-water swimming takes the UK by storm