Since the 1950s, trawler crews from Hull had been recruited by British intelligence to observe and photograph the Soviet Northern Fleet while they were fishing in the Barents Sea. It was called Operation Hornbeam, and crews were provided with cameras and training. Occasionally radio and signals specialists, including staff from the GCHQ site based at Irton Moor near Scarborough, would accompany the trawler crews.
Op HORNBEAM was still around in 1990s and members of the public could phone into a free phone number soviet maritime activity.