The Cruel Sea (Nicholas Monserrat) - A classic, though not without its flaws. The first impression, really, is that it's the prototype for Douglas Reeman's entire output - the tone and style are all right there. It conveys the situation of convoy escorts very well, and really engages emotionally... for the most part. It also does my personal bugbear of swapping POVs during paragraphs, but it's done so well that it works. What doesn't work so much is the set of domestic interludes, which is a shame because these interludes are a necessary part of the structure, but basically in the domestics the tone switches from totally believable and written from grim experience to appalling 40s sub-Coward melodrama in which everybody calls each other darling in ludicrous dialogue. Oh well.
It's also interesting to note that it's from that period where swearing is represented by an m-dash followed by "ing" (you can also see this in Dr No, when the fake dragon's crew do it a lot).
Still, worthy and recommended - should be compulsory reading.