In the inter-war years, the RAN operated six J class submarines, then two Odin class submarines. After a long break, six British-designed Oberon class were purchased; the RAN relied entirely on the Royal Navy for their expertise in submarine escape methods and equipment.
In the years between World Wars, the Royal Australian Navy (RAN) operated six J-class submarines before acquiring two Odin-class vessels. After a period of inactivity, the RAN purchased six Oberon-class submarines designed by the British.  They relied on the Royal Navy for their expertise in submarine escape techniques and equipment.