 In May 1917 the British government requested assistance from the Australian government in dealing with the increasing threat posed by German U @-@ boats . Six destroyers — the Warrego , Parramatta , Yarra , Swan , Torrens and Huon — were sent in response to this request , and undertook anti @-@ submarine operations in the Adriatic , working out of Brindisi , Italy as part of the Otranto Barrage . 
