Teresa, the Collins class subs did have some serious teething problems but they have now matured into world class subs. The early problems were heavily embellished in the press because the "surface Navy" types (who leaked all the information) were hell bent on ensuring that the two optional additional subs (No's 7 & 8) in the original contract, were not built. If the options had been taken up, they were concerned that there would be less money available to build more "floating gin palaces" for them to strut around in.
To a submariner, there are only two types of vessels:- submarines and targets!