The J class submarines J1, J2, J3, J4, J5, J7, were gifted to the RAN. All were built in the UK under the Emergency War Programme with J1 and J2 being built in Portsmouth Dockyard, J3 and J4, in Pembroke Dockyard, South Wales, and J5 and J7, in Devonport Dockyard, Plymouth. They sailed on 9 April 1919 with HMAS PLATYPUS, (submarine depot ship), for Australia, arriving on 10 July 1919 in Sydney.