In terms of maritime detection, I assume you use a network of satellites.
Two South Korean ships came to Canada a few months ago. I do not know whether you heard about this. They entered the St. Lawrence River. Because battleships are not required to have their transponders working, they did not communicate with the St. Lawrence pilots and made their way deep into the channel.
If enemy vessels approached our shores, or if civilian vessels deactivated their transponders, could you detect them ordinarily?