In July 1942 the Japanese liner Tatsuta Maru left Yokohama with the entire British community in Tokyo, who had been interned for 8 months. She stopped in Saigon + Singapore to collect more and docked at Lourenço Marques where they were exchanged for Japanese staff from Europe 1/5

From Wiki:

Tatsuta Maru, marked with symbols of safe passage while working as a repatriation ship as seen through the periscope of the U.S. Navy submarine USS Kingfish (SS-234) in October 1942.