There's an incredible documentary on this. The scale of the engineering, the secrecy of the project, and the environmental challenges are wild.
Azorian: The Raising of the K-129 -- https://www.imdb.com/title/tt2042455/
Azorian: The Raising of the K-129 -- https://www.imdb.com/title/tt2042455/
In terms of {interesting content}:{interesting title} ratio, it's near the top.
Which is to say the title drastically underserves the fascinating content.
It should be something more like "Azorian: How the CIA et al. secretly built a megaship to lift a Soviet sub from 4.9 km under the ocean"
Wow was I wrong. The spy x demonologist x hacker combo just gives Stross more rope to play around with, and is full of fun eccentricities. A strong Anti-Memetics Division vibe. Would recommend.