In southern Cumbria, Helen Skelton takes to the skies in a gyrocopter with veteran pilot Roger to explore a coastline often overshadowed by the Lake District to the north. In Cornwall, Jules Hudson joins marine scientists making waves with a serendipitous discovery - disco scallops. Further up the Bristol Channel, JB Gill faces the Somerset coast at Burnham-on-Sea, where tides race in, and mud flats can trap the unwary