[7] Consequently, Fremantle, which was well out of reach of land-based Japanese aircraft, became the main base of the US submarines,[7] with the first ten arriving by 10 March 1942.

[9] Fremantle provided a safe, large harbour but had the disadvantage of being far away from the submarines' patrol areas and being difficult to reinforce should a Japanese attack take place.

[10] The establishment of the base was directly related to what was known as the Japanese Scare of March 1942, the most significant event for Western Australia being the attack on Broome.

Lockwood's first task was to raise the morale of the submariners under his command, which he perceived as being very low because of the constant retreat they had experienced until then.

[15] Lockwood's other tasks were to replace the aging S-boat submarines in his command with newer models and to deal with reliability issues with the Mark 14 torpedoes used, which were found to run deeper than set in trials ordered by him, causing them to miss their targets.

[17] In January 1943, Lockwood became the head of submarines in the Pacific, with Captain Allan R. McCann acting as his replacement until Rear Admiral Ralph Waldo Christie took over permanently a month later.

Attempts to establish a base further north, at Exmouth, to cut the necessary travel time to the patrol areas for the boats by two days each way, also failed because of unsuitable conditions and a lack of infrastructure there.

Uniquely, these eight were rescued and returned to Australia without ever falling into Japanese hands, being helped by Filipino Guerilla fighters and picked up by another US submarine.

[24] The second half of 1944 saw the arrival of British submarines at Fremantle, which previously had been engaged in the Mediterranean, then moved to Ceylon and, finally, to Western Australia.

It was the first time that Royal Navy ships were based in Western Australia, with the contingent also including two Dutch submarines.

This approach carried a number of risks, it being harder for a submarine to hide in shallow water and the gun crew being exposed to enemy defensive fire.

Porpoise became the first British submarine to go on patrol from Fremantle in September 1944 and was selected, because of its size, to carry Western Australia-trained members of the Z Special Unit on the unsuccessful Operation Rimau.

Christie was most likely replaced because of his insistence of having the late Samuel David Dealey, commander of Harder, decorated with the Medal of Honor, something he did succeed in once back in the US.

[33] There had been some reluctance to attack smaller crafts earlier in the war but, in May 1944, the British Admiralty, allowed the sinking of such vessels in the Far East.

[36] The last of the Fremantle-based submarines to be lost during the war was the USS Bullhead (SS-332), sunk on 6 August 1945, the same day an atomic bomb was dropped over Hiroshima.

[38] From 1942 to 1945, submarines based at Fremantle sank 377 ships, 340 of those sunk by American boats, this figure not including small crafts.

[58] In 2014, the work by Deborah Gare and Madison Lloyd-Jones When war came to Fremantle 1899–1945 gives a pictorial and textual understanding of the impact of the allied servicemen associated with the submarine base.

[59] Also collections of oral history in Battye Library include numbers of people remembering from their childhood the impact of the base, and of American servicemen living in Perth in the 1940s.

[61] Western Australia saw far less US service men pass through than the eastern States, where up to 100,000 US military personnel were present at its peak.

[62] For the isolated Western Australian population, the presence of a submarine base at Fremantle also alleviated the fear of being abandoned and defenceless, especially in the early stages of the Pacific war when the state felt under threat of a Japanese invasion or attack with very limited defences.

[63] African American submariners based in Fremantle reported being treated well and without prejudice, in contrast to the East Coast, where the first contingent arriving in Melbourne in 1942 was barred from landing by custom officials, something overridden by Australian authorities.