In 2013, Sean Conway embarked on his bid to be the first person to swim the length of Britain, raising money for the charity War Child. Accompanied by three support crew on a tiny, leaky yacht, he set out from Land's End, aiming to hit John O'Groats in two months. From swimming alongside a dolphin and amidst stunning night-time phosphorescence, to tackling treacherous tides and growing a huge beard to protect himself from jellyfish stings, this is a story of immense courage and determination over an incredible 900-mile journey.