Which submarines suited Pacific Dominion service?

What type of interwar submarine would have suited Australia and the other Pacific Dominions?

An O- or Odin-class design offered a plausible long-range model, while smaller boats could strengthen local defense.

Australian submarines needed enough fuel and endurance for Pacific distances, although smaller boats could still add a defensive layer close to Australia. British T- and S-class submarines later operated from Australia, while the 1929 S class illustrates the smaller end of the interwar options. The larger O or Odin class offered a plausible model because it was conceived for distant service and included boats ordered for the Royal Australian Navy. Its long surfaced range made that design a plausible basis for the patrol areas imagined for an Empire submarine force.