John Dalley was one of several key personnel who was ordered to be evacuated from Singapore before its capitulation. He boarded a forty-foot Royal Navy motor launch known as the "Mary Rose" at Keppel Harbour, where it would sail to Palembang, Sumatra, part of the Dutch East Indies. The Mary Rose, commanded by veteran naval officer Captain George Mulock DSO, RN left Singapore a little before midnight on 14 February. However, they were caught by two Japanese patrol vessels and were forced to surrender. Dalley survived the war, and submitted a positive report on the unit in 1945–46.