When the UK entered the Second World War in September 1939 "Rohna" was in the Indian Ocean. Apart from a voyage from Karachi to Suez with Convoy K 4, "Rohna" operated unescorted between Rangoon and Madras until late November. On 10 December she left Bombay for the Mediterranean, passing through the Suez Canal on 20–21 December and reaching Marseille on 26 December. From 3 January 1940 until 10 March she operated unescorted between Marseille and Port of Haifa in Mandatory Palestine, at first in convoys but after 29 January independently.