The dates and times in this book vary in a number of instances from those recorded in official Australian documents. For example, the reconnaissance flight over Sydney Harbour by a Japanese seaplane occurred in the early morning hours of 29 May, not 30 May 1942 as recorded in the official Australian history. Other inaccuracies in the historical record include the time when the dockyard floodlights were extinguished on Garden Island at 12:25 am on 1 June; not an hour earlier at 11:25 pm on 31 May 1942 as recorded in the official naval history.
All times are expressed according to local geographical time zones. During World War II, Japanese naval activities operated on Japanese time (GMT +9). Times taken from Japanese historical records have been converted to local geographical times.
The Japanese Imperial Navy also used the metric system of measurement, while the Allied Navies used the Imperial system. All measurements in this narrative are expressed according to their source to better reflect the period.
Many historical accounts of the attack on Sydney Harbour adopt the names of the midget submarines recorded in the official history. In fact, the official report lists four midget submarines, whereas only three took part in the Sydney Harbour raid. For simplicity, I have named the midget submarines to correspond with that of their carrier submarines.