After the war, the British Admiralty decided that the best way to protect the Pacific region was with a force of submarines and cruisers. To this end, they offered the six surviving submarines of the J class to the Royal Australian Navy as gifts. "J1" and her sisters were commissioned into the RAN in April 1919, and sailed for Australia on 9 April, in the company of the cruisers and , and the tender . The flotilla reached Thursday Island on 29 June, and Sydney on 10 July. Because of the submarines' condition after the long voyage, they were immediately taken out of service for refits.