This work has been a long time on the slipway. In some ways the keel was laid unwittingly in my childhood by a Guernsey sea captain who gave my father a fine engraving of Admiral Lord de Saumarez and a copy of Ross's two-volume biography. I passed that portrait every time I went up or down stairs. In time I turned to the books and noticed that the admiral had professed just the same kind of evangelical faith that my parents held. My father was a master mariner who had served with the navy in both world wars. Amongst his close Christian friends were the Guernseyman – former Commodore of the British India Steam Navigation Company – and a senior master in the Union Castle line. The connection between faith and seafaring seemed something to explore, and accordingly I undertook part-time research into aspects of this at Southampton University under the skilled and generous supervision of the late Professor John Bromley. When at last I retired from a career in teaching I found time to develop my earlier work and to prepare it for publication.

Over forty years I have valued the help and encouragement of many people. I am grateful to the governors of Monkton Combe School for allowing me a term's leave of absence to start my research, and of Luckley Oakfield School for granting me a sabbatical term in 1999 to begin more focused writing. The staff of the National Maritime Museum, the National Archive at Kew, the British Library, the Naval Historical Library, Southampton University Library, the SPCK and the Scripture Gift Mission made my researches a pleasure. Professor N. A. M. Rodger, who knows so much about every aspect of naval history, and Surgeon Vice-Admiral Sir James Watt who understands the correlation between Christian faith, medicine and the navy better than any living authority, have both encouraged this study and helped with their advice and expertise. Dr Roald Kverndal with his unrivalled knowledge of seafarers’ missions both British and global has been a particular inspiration.

The present Lord de Saumarez has kindly given permission to publish extracts from the private papers of Admiral Sir James Saumarez. I am grateful to Peter Sowden for all the encouragement, advice and practical help he has given me in preparing the book for publication.