Something tells me that if there were so much as an Iranian dinghy sitting off the coast, the military would be extremely aware of its presence. Monitoring absolutely everything that it did.
Something tells me that if there were a bus-sized Chinese spy balloon floating all the way across the continental US, the military would be extremely aware of its presence.
(As I recall they were, but they would not publicly acknowledge it until the public sightings became undeniable.)
what/who ever that something is that is telling you that, i'd suggest a better source. it is part of the "game" that militaries the world over try to do things without their opponents knowing they were ever there. international boundaries are 12 miles of water, yet navy submarines get much much closer than that as a matter of course.
do you think the military or any 3 letter agency knows 100% where all foreign spies are within their borders?
(As I recall they were, but they would not publicly acknowledge it until the public sightings became undeniable.)