The Turning Tide is a hymn to a sea passage of world-historical importance. Combining social and cultural history, nature-writing, travelogue and politics, Jon Gower charts a sea which has carried both Vikings and saints, invasion forces and furtive gun-runners, writers, musicians and fishermen. The divided but interconnected waters of the Irish Sea - from the narrow North Channel through St George's Channel to where the Celtic sea opens out into wide Atlantic - have a turbulent history to match the violence of its storms.

Jon Gower is a sympathetic and interested pilot, taking the reader to the great shipyards of Belfast and through the mass exodus of the starving during the Irish Famine in coffin boats bound for America. He follows the migrations of working men and women looking for work in England and tells the tales of more casual travellers: sometimes seasick, often homesick too. The Irish Sea is also a place with an abundant natural history.

The rarest sea bird in Europe visits its coasts in summer while the rarest goose wings in during winter. Jon Gower navigates waters teeming with life, filled with seals and salt-tanged stories and surveyed by seabirds. At a time when Irish affairs feel like they are building towards an historic crescendo, he tells the story of the people who have crossed these waters, and who live on their shores.

Lyrically written and deeply considered, this is a remarkable and far-reaching book.