The sea lanes of the Atlantic played a vital role in the transport of troops, equipment, and supplies from North America to Europe. The battle for control of the Atlantic Ocean began on 3 September 1939 with the sinking of British passenger liner by the German submarine U-30. Australia’s part in the campaign in the Atlantic was multi-faceted.
RAN Ships such as HMAS Australia, and the N-class destroyers HMA Ships Napier, Nepal, Nestor, Nizam and Norman escort duties throughout the Atlantic. In addition, to sinking U-127, Nestor was also involved in the hunt for the famous German battleship, KMS Bismarck.
Training depot HMAS Rushcutter, now known as HMAS Watson, also played a crucial role, in supplying officers and ratings trained in antisubmarine warfare. Some sources suggested that up 20 percent of those involved in the Atlantic conflict had been trained at Rushcutter.
For more information, please see http://www.navy.gov.au/history/feature-histories/australian-sailors-battle-atlantic (www.navy.gov.au)
 Djokovic, Petar. “Australian Sailors in the Battle of the Atlantic.” Royal Australian Navy – Feature Histories, viewed 05/04/2016, http://www.navy.gov.au/history/feature-histories/australian-sailors-battle-atlantic. (www.navy.gov.au)
In addition to warships, a number of RAAF Squadrons attached to Coastal Command carried out extensive Maritime patrol and anti-submarine operations over the Atlantic as part of the campaign to counter the threat posed by German U-Boats.
Nos 10 and 461 Squadrons operated Sunderland Flying Boats from bases in Plymouth and Pembroke Dock on the south coast of the U and as far afield as Oban in Scotland ranging out over the Bay of Biscay and the Atlantic. Units such as 455 Squadron carried out maritime strike operations over the North Sea, Norway and the Normandy beaches as part of D Day operations, equipped with the potent Bristol Beaufighter. In adidtion hundreds of RAAF aircrew served in RAF units of Coastal Command as well and RAAF pilots operated seaplanes that were launched from Crusiers such as HMAS Australia.