The Guardian has an interesting article about daily life for submariners. It’s mostly silent on what they do when on duty (perhaps understandably so) but is full of little details about life while off-duty, such as that sailors often sleep next to the Cruise missiles as they are cooler.
They have long postings on board and you get the sense from the article that most of the men consider being a submariner, as opposed to a surface sailor, to be something of a calling. They love it. The other aspect which really comes through is their relationships. With space at such a premium life on board is much less formal than other military settings and the fact that they are underwater and therefore in constant danger means each man must trust the others to do their jobs safely and well.
I don’t think I could do it though!