While a feet of engineering, purists point out this was not fully submerged. The sub returned to the surface regularly for navigation, poking up its periscopes for star fixes and photographs. The ability to navigate the world ocean totally free of the surface, perhaps spending months under ice, had not yet happened.
I can't find any of them now but there was a satirical series of posts on (I suspect usenet before) reddit about life on-board a nuclear submarine as an ordinary sailor.
That kind of humour often encodes realities of lived experience. Life inside a tube, sharing bunkbeds, sleeping next to machinery, toilets which explode, boredom and terror.
while it's not on that kind of level, but the wikipedia page on operation Sandblast (https://en.wikipedia.org/wiki/Operation_Sandblast) has a few details on the daily life aboard, between weekly routine and maintaining the machinery. Also "Beach [the captain] maintained that the greatest challenge facing the crew was a seemingly mundane activity, garbage disposal and cleaning"
That kind of humour often encodes realities of lived experience. Life inside a tube, sharing bunkbeds, sleeping next to machinery, toilets which explode, boredom and terror.