Christian Lewis had hit rock bottom, suffering with depression so severe he would shut himself in his bedroom for weeks. In August 2017, while surfing - his only respite - he cast his eyes along the coastline and realised it was the only place he really wanted to be. Making an impulsive decision to walk the entire coastline of the UK, he spent just a few days rustling up a tent and walking boots then left for good with just a tenner in his pocket...