is it based on a (half) true story ?
In January 1968, the 15th Submarine Squadron was part of the 29th Ballistic Missile Division at Rybachiy, commanded by Admiral Viktor A. Dygalo. K-129's commander was Captain First Rank V.I. Kobzar. K-129 carried hull number 722 on her final deployment during which she sank on 8 March 1968. The Soviet Navy deployed a huge flotilla of ships to search for her but never found her wreck
http://en.wikipedia.org/wiki/Soviet_submarine_K-129_%281960%29
any ressemblance with that ?