> the Sound Surveillance System (SOSUS), a complex array of hydrophones fixed on the ocean floor and connected by cables to secret listening stations set up along coasts all over the world.

One for the conspiracy theorists...

Secret-ish.

One of the links terminated in a seeming boathouse at Andøya in Norway.

It was a landmark. As in, if you were going fishing with a colleague and asked him which boathouse we'd embark from, he was as likely as not to say 'Three boathouses down from the hush one!'

Look up the local names for Tongue of the Ocean and you'll have even more gist for that mill.

No conspiracy needed, SOSUS was a known fact, the Soviet Union made attempts to find and disable the hydrophones, Tom Clancy wrote many a novel in which SOSUS was mentioned or played a role, etc. It was the ocean equivalent of the Key Hole satellites, used to monitor the movements of Soviet 'boomers' - nuclear missile subs.