You miss the point entirely . There is no way that submarines, either nuclear or diesel, can protect our coasts or our ports. How exactly do you propose that they do that ? Do they simply blockade the ports so that no enemy surface ships or submarines can approach ? I would love to see that!
Is the objective to protect incoming convoys of oil tankers or other ships carrying vital supplies ? Yes lads, we will just wait outside Sydney Heads and Port Philip Bay and just hope that the enemy does not try to sink them before that lol
