I wonder if we would need a substantial, almost the same amount spent on drones, as with Subs (needs to be costed ~ might be significantly cheaper) to protect Australia & the submarines. With Australia's unique geography & large expanse of water, drones to take out battleships and aircraft carriers and submarines make sense. It is questionable how long submarines will last, especially without drone support. In the old days if a submarine gave off a ping a battleship would need to check out the ping & both vehicles would be aiming at each other.
