British merchant ships changing crews for war risks according to a letter of the German naval attaché at Istanbul dated 2 December 1939

In his letter dated Istanbul, Turkey 2 December 1939 No. 491 g. reported the German naval attaché to the Oberkommando der Wehrmacht Abteilung Ausland that the British steamship Herland lying here signed off her Mediterranen crew due the large danger when going to England. Part of the crew of the British steamship Socony signed off for the same reason in the USA and arrivered here with an American steamship.

Source

Bundesarchiv. German Marineattaché for Turkey, Greece, Romania and Bulgaria 1939-1941. RM 12-II/459.