If you want nuke boats, you’d be hard pressed to find a better source than Newport News or Electric Boat.
The Aussies want diesel boats.
If you want good diesel boats, you need to look somewhere else. Germany and Japan come to mind ...
Electric Boat has a lot of experience building diesal subs.
Everyone of the subs we built during WWII was a diesal sub.Well actualy a diesal electric sub.
With the improvements in technology today,I’m sure that they could build very capable diesal boats.
Kockums AB in Malmo, Sweden make EXCELLENT submarines, as well as German shipyards in Kiel.