Of the almost 9,000 emergencies the RNLI's lifeboats launch to every year, just seven per cent are to commercial vessels. The vast majority of their shouts are to those using the water for pleasure, to people who never intended to get in the water in the first place and shore-based rescues from cliffs and beaches. Off the coast of Northumberland, the Holy Island of Lindisfarne is connected to the mainland by a tidal causeway, exposed at low water but submerged at high tide. When the car of a young family is caught on the causeway by a rising sea, ten miles away the crew from Seahouses lifeboat station are paged and must race the tide to rescue them before the car is submerged or swept away. In Ireland, the crew of one of the RNLI's few inland stations, Lough Derg, faces a rough ride when the pagers sound a few days after Christmas. Launching onto a cold, windswept and choppy lake, they must find two capsized kayakers who are close to drowning. On Dorset's Jurassic Coast, the crew at Lyme Regis must scale a crumbling, treacherous cliff face in the pitch dark to rescue a fossil hunter cut off by a rising tide.