During WWII on the 19th of February 1942 , the Japanese flew 64 raids on Darwin and 33 raids on other targets in Northern Australia. The Japanese used a total of 242 aircraft through 2 separate raids. Four Japanese aircraft carriers, Akagi, Kaga, Hiryu and Soryu were used, all four were also used during the bombing of Pearl Harbour. On the day there were 65 Allied warships and merchant vessels in the harbour at Darwin and 30 aircraft at the Darwin Civil and RAAF airfields. The only air defences that Australia had during the attack were ten fighter planes. The total weapons loss for Australia were twenty military aircraft, eight ships anchored in the harbour and most civil and military facilities in Darwin were destroyed.
During May and June of 1942 Japanese submarines made a series of attacks on Sydney and New Castle. On 31st May 1942, 3 submarinesI-22, I-24 and I-27, each of these submarines launched a Type A midget submarine. The main target for these attacks was an American heavy cruiser, the USS Chicago, the Japanese hoped to sink this and other warships anchored in the harbour. Submarines I-22 and I-27’s midget submarines were detected, the naval officers aboard upon realising that they were trapped decided to blow up their craft and themselves. Submarine I-24 fired two torpedoes at the USS Chicago; however, both missed their intended target, one ran ashore and failed to explode, the other struck a seawall on Garden Island it exploded on impact beneath the ferry Kuttabul. The Kuttabul sunk immediately. This submarine was not found until 2006 when divers discovered the wreckage off Sydney’s northern beaches. The mother submarines then carried out raids on shipping vessels in eastern Australia until the 8th of June.
An ABC Report (2012) on the Bombing of Darwin
A recount of Japanese Ko-hyoteki midget submarines attack Sydney Harbor, Australia in 1942.