Martin’s father, Edmund Nelson (1910-2007), was a portrait painter; he painted among others the historian G M Trevelyan, the writers E M Forster and G B Shaw, and the cricketer C B Fry.
There were many diaries kept during the long convoy journeys of World War Two, but his is exceptional for being illustrated with charming line drawings throughout. It is in the Imperial War Museum archive. The diaries were subject to censorship, but interpreting the sketches allowed Martin, with expert assistance, to track down the details of the convoy.