Axis naval activity in Australian waters
[5] The Australian naval authorities did, however, close ports to shipping at various times following real or suspected sightings of enemy warships or mines prior to June 1942.
[14] These defences consisted of fixed anti-submarine booms and mines supported by small patrol craft, and were also greatly expanded as the threat to Australia increased.
A 1989 inquiry undertaken by the Repatriation Commission found that merchant mariners were exposed to greater risks than many members of the RAN as they more frequently operated in dangerous waters and their ships were not designed to survive attacks.
Orion sailed south-west after sinking Turakina, passing south of Tasmania, and operated without success in the Great Australian Bight in early September.
[27] The most serious effect of the raid was the fall in phosphate output, though decisions made as early as 1938 to increase stockpiles of raw rock in Australia mitigated the decline.
[25] On 19 November 1941, the Australian light cruiser HMAS Sydney—which had been highly successful in the Battle of the Mediterranean—encountered the disguised German raider Kormoran, approximately 150 mi (130 nmi; 240 km) south west of Carnarvon, Western Australia.
Acting in support of the Japanese conquest of the Netherlands East Indies, these boats laid minefields in the approaches to Darwin and in the Torres Strait between 12 and 18 January 1942.
[35] Being the first accessible ocean-going IJN submarine lost after the attack on Pearl Harbor, USN divers attempted to enter I-124 in order to obtain its code books, but were unsuccessful.
A raid conducted by 54 land-based bombers later the same day caused further damage to the town and RAAF Base Darwin and the destruction of 20 Allied military aircraft.
The small general purpose vessel HMAS Patricia Cam was sunk by a Japanese floatplane near the Wessel Islands on 22 January 1943 with the loss of nine sailors and civilians.
[45] In March 1942, the Japanese military adopted a strategy of isolating Australia from the United States, which involved capturing Port Moresby in New Guinea, the Solomon Islands, Fiji, Samoa and New Caledonia.
The goal of these patrols was to find a suitable target for a force of midget submarines, designated the Eastern Detachment of the Second Special Attack Flotilla, which was available in the Pacific.
These torpedoes missed Chicago but sank the depot ship HMAS Kuttabul, killing 21 seamen on board, and seriously damaged the Dutch submarine K IX.
[65] As the Japanese force was too small to cut off all traffic between Australia and New Guinea, the squadron commander widely dispersed his submarines between the Torres Strait and Wilson's Promontory with the goal of tying down as many Allied ships and aircraft as possible.
[68] The historian Geoff Crowhurst believes that RAAF aircraft searching for I-174 probably sank I-178 during the early hours of 18 June, but the cause of this submarine's loss during a patrol off eastern Australia has not been confirmed.
She was clearly marked with a red cross and was fully illuminated, but the light conditions at the time may have resulted in Nakagawa not being aware of Centaur's status, making her sinking a tragic accident.
[76] While gunfire was sighted by nearby coastwatchers, Allied naval authorities only learned of the attack when Torisu's battle report radio signal was intercepted and decoded a week later.
On 15 June she sank the 7,715-long-ton (7,839 t) Norwegian tanker Høegh Silverdawn about 1,800 miles (1,600 nmi; 2,900 km) west-north-west of Fremantle while she was sailing from that port to Abadan, Iran.
Between 17 and 20 January 1944, members of a Japanese intelligence unit named Matsu Kikan ("Pine Tree Organisation") made a reconnaissance mission to a sparsely populated area on the far north coast of the Kimberley region of Western Australia.
The appearance of a powerful Japanese force at Singapore concerned the Allies, as it was feared that it could potentially conduct raids in the Indian Ocean and against Western Australia.
Following this attack the squadron broke off its mission and returned to Batavia as it was feared that Allied ships responding to Behar's distress signal posed an unacceptable risk.
In early March 1944, Allied intelligence reported that two battleships escorted by destroyers had left Singapore in the direction of Surabaya and an American submarine made radar contact with two large Japanese ships in the Lombok Strait.
The Japanese ships detected in the Lombok Strait were actually the light cruisers Kinu and Ōi which were covering the return of the surface raiding force from the central Indian Ocean.
[86] On 14 September 1944, the commander of the Kriegsmarine—Großadmiral (Grand Admiral) Karl Dönitz—approved a proposal to send two Type IXD U-Boats into Australian waters with the objective of tying down Allied anti-submarine assets in a secondary theatre.
The submarine achieved its first success on this patrol when it attacked the United States-registered Liberty ship Robert J. Walker off the southern coast of New South Wales on 24 December 1944.
[100] As southern Australia was thousands of kilometres behind the active combat front in South-East Asia and had not been raided for several years, there were few anti-submarine assets available in this area in late 1944 and early 1945.
[17] The official history of Australia's role in World War II states that a total of 654 people were killed on board the vessels sunk by submarines, including approximately 200 Australian merchant seamen.
[104] In his PhD thesis David Joseph Wilson estimated that at least 104 members of the RAAF were killed during maritime patrol and anti-submarine operations off the Australian coast, with at least 23 aircraft being destroyed.
[110] This forms part of broader limitations in the literature on the defence of the Australian mainland during the war, which includes a lack of any published works providing a comprehensive single-volume history of the topic.
[17] A large number of specialist Australian works discuss various aspects of the operations, and the history of the Seamen's Union of Australia covers the experiences of civilian mariners.
