Adrian Edmondson sets sail to explore Britain's maritime past and meet people whose lives are influenced by the sea today. He begins in Brixham, Devon, where he joins the crew of one of the fishing town's oldest trawlers and investigates the area's connection to a well-known hymn. He then takes a helicopter ride out to Eddystone Lighthouse, the first of its kind to be built on a rock at sea.

Adrian Edmondson sails around the Thames Estuary, which was once part of one of the most important trading routes in the world. Starting his journey at Chatham Dockyard, he meets master rope-maker Fred Cordier to find out how his predecessors played their part in supporting the Navy's fleet of warships, including Nelson's HMS Victory. The presenter also visits the deep-water port London Gateway, where he takes hold of a crane's controls, before encountering one of the unusual features of the waterway - the Maunsell Forts.

Adrian Edmondson sails the coastline around Bridlington, East Yorkshire, once a major port for North Sea fishing but now more reliant on other seafood for its survival. He meets a lobster and crab fisherman whose family has worked in the area since the 17th century and tracks down a flat-bottomed boat that was built more than 100 years ago. He also takes to the cliffs of Flamborough Head to find out about the perilous pursuit of climming and joins a local RNLI crew on a training drill.

Adrian Edmondson climbs aboard the former RNLI lifeboat Chieftain to learn about the 19th-century river pilots who guided ships through the dangerous waters of the Bristol Channel, which has the second highest tidal range in the world. In the port of Barry in the Vale of Glamorgan, he joins some of their successors as they pilot a cargo ship through the locks and narrow paths of the channel. Ade then heads to Black Rock, where he meets a group of people preserving an ancient method of salmon fishing, before taking a trip on the Olga, one of the few surviving traditional pilot cutter boats from years gone by.

Adrian Edmondson sails out to the Isle of Eigg in the Inner Hebrides, joining its small community to find out about the challenges that come with living on a remote island. Returning to mainland Scotland, he arrives at Mallaig in the Highlands, which was one of the busiest ports in Europe during the 1960s, known for its kippers and herring trade. Ade then finishes this week's journey with a team of sailors circumnavigating Britain.

Adrian Edmondson sails along the north-west coast of England and down the Mersey to Liverpool. Starting his journey at Eastham, where the Manchester Ship Canal connects with the river, he explores the vital role of tugboats in the 19th century, which towed large cargo ships along narrow waters, and joins three generations of a family as they haul a 3,000-ton vessel along the canal.