The quick answer seems to be: yes. Once humans are removed from the equation, submersibles retain all the advantages of extreme stealth and add greater endurance, far deeper diving depths – and they are orders of magnitude less expensive to build and support. The loss of one or more of them during hostilities would be of little consequence – unlike a crewed submarine, the sinking of which would be a national disaster.
In the Australian context, they could start their missions from a naval facility, commercial port, or be deployed and recovered from a surface ship. With the right navigation systems and artificial intelligence, they could find their way to and from areas of interest, remaining there undetected for extended periods of time, gathering data and periodically reporting back – just like something with people in it, but without the risk or the expense.
Some analysts argue that there will always be a role for crewed submarines, though their usefulness seems to be diminishing over time. The popular idea of using them as a mother ship doesn’t always make a lot of sense because how does this concept add value compared with scenarios where the UUVs are being controlled from their home base and send data back directly to it, rather than via an expensive and vulnerable object in the form of a submarine? It seems to make sense to eliminate the middleman.
While almost all the public focus has been on AUKUS and particularly the acquisition of nuclear-powered submarines, it seems the RAN is very wisely hedging its bets and has several parallel activities underway in the XL-UUV domain. The most high-profile of these is with U.S. tech company Anduril, although Canada’s Cellula Robotics is working with local entity Trusted Autonomous Systems on something similar called SeaWolf.