German U-boats routinely patrolled just outside the 12 mile international limit during WW2 off the East Coast. The German navy could see the city lights of Atlantic City, Boston, Miami, New York etc., out of their periscopes.
Uh, no, they came right on up and sank ships in the harbors. There are credible rumors in Savannah that an entire U-Boat crew ate dinner in a restaurant on Tybee Island. I know a man who was a youngster living on Tybee Island during the war. He and his buds spent a lot of time at night spotting for the Coast Guard. They reported six. One was signalling someone on shore using Morse code flashed from the periscope.