I was stationed at Lajes Field, Azores,Portugal in the late Seventies. I walked out of the Comm Squadron Building on morning after a Mid-shift to see a Hammer and Sickle on the Rudder of a plane not even fifty feet away from me. That was a shock! That plane stayed there for a few weeks, our crypto gear be damned.
I served on USS Memphis (SSN 691) in the early 1980’s. We used to wait off the Murmansk Inlet and then trail Soviet Yankee class SSBNs as they left their bases at Polarny and Gadzhiyevo. We would maneuver so as to be deep in his starboard quarter at a range of 5,000 to 7,000 yards where we had solid passive sonar contact. In this position, almost astern of the Yankee, we were in the baffled area of his sonar system and he was unable to detect us.
We would trail the Yankee all the way to his “patrol box” which was 500 to 1,000 miles off our East Coast. Then P-3 Orion ASW aircraft flying out of Bermuda would locate and track the Yankee. We would come to periscope depth, raise a radio antenna and communicate with the P-3 to take over the trail.