Watch Coast Season 5 in Australia

In this first episode the team embark on an extraordinary circular tour of the Irish Sea to visit every country and territory within the United Kingdom. The hub for this wheel around the heart of the British Isles is the Isle of Man where Neil Oliver explores the small island. On the edge of the Irish Sea at Morecambe Bay, Alice Roberts gets trapped in quicksand to discover why it is so sticky and so deadly. In Northern Ireland, Miranda Krestovnikoff sees how seals cope with the struggle to find food as they bring up pups in the beautiful inland sea of Strangford Lough. Nick Crane goes sea cliff climbing on the remarkable rocks of Anglesey as he explores why this corner of North Wales is the site of some of Britain's biggest earthquakes.

Neil Oliver performs the lead role in an extract from Shakespeare’s "The Tempest" on the stage of a remarkable coastal amphitheatre near Land's End. Nick Crane ventures out into the infamous "Portland Tidal Race" to see how this fearsome tidal surge creates some of the roughest waters in Britain, surprisingly close to the tourist beaches and Georgian splendour of Weymouth. Miranda Krestovnikoff goes in search of a family of White-Beaked Dolphins and Alice Roberts follows her nose to discover what gives the sea its distinctive smell. In Devonport, Mark Horton has privileged access to the historic dockyards to see where the wooden ships of Nelson’s Navy were built. Mark reveals how the steel fleet of the modern Royal Navy still relies on the age old skills of wood working.

Neil Oliver explores the province of Finistère, "The End of the Earth", and meets a lighthouse keeper made famous by one of the world's most reproduced photographs. Nick Crane joins the "Onion Johnnies", who gave us our stereotypical image of a Frenchman, complete with stripy tee shirt, beret and bicycle laden with onions. Alice Roberts reveals the life saving chemical element that's locked away inside seaweed and Miranda Krestovnikoff dives for a seafood delicacy. At Carnac, Mark Horton wanders amongst the mysterious lines of standing stones, erected thousands of years before Stonehenge, to investigate their age old connection with Britain.

Neil Oliver takes part in an aerial dogfight to discover why a Nazi flying ace landed his top secret new plane on Welsh tarmac at the height of the Second World War. Miranda Krestovnikoff visits a seabird paradise, the magical island of Skomer, and at Porth Oer, Alice Roberts attempts to solve the riddle of the "Singing Sands". What makes some very special British beaches whistle when you walk on them? Mark Horton visits and imposing castle at Harlech, one of the best preserved in Britain. Nick Crane explores the violent history of smuggling around the gorgeous Gower Peninsula and abseils into an extraordinary stone structure concealed in the side of a sea cliff.

Just five months before President John F. Kennedy was assassinated in Dallas, he was riding in an open top limo through the crowded streets of Galway. Neil Oliver meets the photographer who managed to get up close and personal with the President and talk him into the perfect snap. Miranda Krestovnikoff explores an odd little island where the mountain hare population is thriving and Nick Crane investigates a local legend that says that Clew Bay has 365 islands, one for each day of the year. Alice Roberts unearths the remarkable remains of the oldest farm in the British Isles.

Neil Oliver joins the crew of the last surviving coal fired, steam-powered, "Clyde Puffer". Amateur artist Alice Roberts explores what drew Joan Eardley to Catterline and how her life was cut tragically short on the verge of great success. Nick Crane reveals how the majestic Loch Ness became part of Britain's biggest building project in the early 1900s. Miranda Krestovnikoff dives into Loch Creran to explore how the tiny worms built a giant reef known as Worm City. Hermione Cockburn visits the "Islands that Roofed the World" and Mark Horton unearths what remains of the mysterious and violent people who once ruled much of Scotland, the Picts.

The Danes top the polls as the happiest people on earth and Neil Oliver wants to know what they have to smile about. Nick Crane investigates how the Danish made a big business out of selling bacon to Britain. Alice Roberts sets sail in a full scale replica of a Viking longship to see how these ships gave Norsemen the advantage over the English in battle. Miranda Krestovnikoff meets some unflappable red deer. On Heligoland, Mark Horton reveals how in 1947 Britain's Royal Navy blew this tiny island apart in the largest non-nuclear explosion the world had ever seen and Dick Strawbridge gets access to the construction of one of the world's largest offshore wind farms.

Neil Oliver visits the birth place of his seafaring hero Lord Nelson. On the eerie shingle bank of Orford Ness, Alice Roberts leads a team trying to recreate the original war-winning experiment which proved that Radar would work. Off the Norfolk coast, Nick Crane explored the remarkable lost world of "Doggerland". Miranda Krestovnikoff wades out into the mud of the Wash", a vast tidal feeding ground for migrating birds. To investigate the appeal of the glorious Essex Fishing Smacks, Mark Horton joins a crew on competition around the Thames Estuary.