“And all around was the glory of sea and cliff and sky with their everlasting wonder of change and detail.” It’s the spring of 1940. Antony Bridges and Margaret Townsend, judged unfit for regular war service at sea because of his disability and her gender, are using the 15-ton ex-King’s Lynn pilot cutter, Mermaid, to run cargoes of gelignite and detonators across the Pentland Firth to assist the refortifying of the naval base at Scapa Flow. It’s cold, hard and dangerous work, yet Antony’s sensitivity to the everchanging beauty of the natural world and the raw power of wind and wave remains compelling.

The venture becomes more complex. They add a majestic sailing trawler and a battered metal drifter to their fleet, become ensnared by officialdom and increasingly conscious of the bravery and idiosyncrasies of the local fishermen. Their efforts are but a tiny fragment in the overall tapestry of WW2, yet the quality of their loving, working partnership and the bleakly magnificent Scottish setting makes this book outstanding.