What is with all of this "super sneaky board party super swift" stuff? I mean, both options you offered go your way.
I don't see how you cannot see this situation:
The port security officers checked the crates they wanted to see. No compliance means you were to be sent out. This would have taken hours, mind you, and the bigger crates would have been targeted due to the given that "the cargo ships were carrying whale meat" most likely taken from the captain(s) per regulation.
Two port security vessels met up with the two cargo ships. Both were obviously prepared for pirate boardings etc. due to their role in protecting the port, so I don't see how "british looking japanese men in british looking uniforms" take two security vessels without them notifying the three armed military destroyers in the harbor/port. Besides, the submarines could have been basically detected due to sonar. Yeah, super sneaky submarines, but one blimp can alert the whole port.
The trip to get to the god damn port in general is basically impossible due to you saying that you didn't refuel at all (who in their right mind would allow japanese submarines to refuel?). Of course, the cargo ships would have had an excuse. And yes, you said you went around Australia.
Australia.
Let us inspect the beginning of this whole parade: When you said imperial ships, you basically implied military. And, don't get me wrong here again, but whenever I tried to "edit" something I have done in the past (not something little, I mean something like a tiny invasion party against another person's country), I would have been yelled at some more for being a floundering idiot.
This is just my look on this tiny invasion by Japan.
The northern British defensive front continues well, primarily for being well defended/prepared and the mines+machine gun placements. However, tanks have pushed through one side of the defense, but friendly tanks will fill that gap. I-RAF are already on the scene. Britain wishes to contact the Soviet government with the demand of a ceasefire.
Britain wishes to wonder why the Soviets are invading India.
Men are being shipped to India, and the volunteers for the Indian army help a lot in the defensive front.
Oh, and France, help pls.