Half of the world's population lives in coastal regions lapped by tidal waters. Yet how little most of us know about the tide.

With Aldersey-Williams as our guide to the most feared and celebrated tidal features on the planet, from the original maelstr m in Scandinavia to the world's highest tides in Nova Scotia to the crumbling coast of East Anglia, the importance of the tide, and the way it has shaped - and will continue to shape - our civilization, becomes startlingly clear.