Ian Marchant tracks the River Ancholme in Lincolnshire back to its source. Sights include Humber Sloop Amy Howson, an ochre-sailed ship moored at the mouth of the Ancholme, and Brigg Raft, a five-metre Bronze age raft designed specifically for the slow moving waters of the Ancholme. Just off the course of the Ancholme is Stow Minster which has, etched into its stone, two images of Viking longships
