The reluctance of Australia to invest adequately in defence mirrors those countries in western Europe and with even less excuse. The US is a powerful ally, but the Seventh Fleet operates mostly in the northern hemisphere. The Australian Navy's impending loss of a medium-range air defence capability is a serious blow, with no obvious solution in sight other than buying discarded US destroyers with all the logistic and manpower problems that would entail. Flow noise, cavitation inception and automated combat data systems are being incrementally improved. The arcane subject of acoustic vulnerability has been so simplified by the defence press as to be almost meaningless.
All submarines are stealthy, it is just a matter of degree.
More serious are exhaust back-pressure stresses when the submarine is snorting in rough weather, and questions over the reserve of buoyancy and righting moment when surface running or diving in a seaway. Watertight integrity doubts have also been raised. These are issues fundamental to the operation of the submarine, and it is not encouraging that the Navy is far short of the trained numbers needed to man six submarines, although this probably has much to do with stationing them at Fleet Base West at the nether end of the continent. This is a resourceful navy with high operating standards. If Australia wants to keep it that way, it is going to have to inject more money, particularly now that the carefully constructed accord with Indonesia has been so brutally shattered.