One of the key elements that helps to define the film's tone is one that I suspect many people overlook: Alan Rawsthorne's marvellous score.
Take this scene for example, in which HMS Compass Rose is making its maiden voyage. In the hands of a lesser composer, the music would probably be very upbeat and bombastic, but Rawsthorne has written something far more interesting:
(For some reason, the clip doesn't play on some phones)
When a handful of dockyard workers cheer from the quay, instead of adding a patriotic flourish, Rawsthorne's music emphasises the pathos of the scene, with the young, inexperienced officer shyly half-saluting in reply, as the small, vulnerable corvette leaves the safety of its harbour. The atmosphere reminds me a little of a Ravillious painting, from his time as a War Artist.
The use of music is also particularly effective in the next clip, setting the scene, but also knowing when to quietly bow out so that the most harrowing moments take place in silence. The two sailors are the brother and husband-to-be of a widow called Mrs Bell:
And in the film's key scene, there is no music at all. Jack Hawkins doesn't need any help:
Of course, the brilliance of The Cruel Sea is a team effort and with names like Eric Ambler, Charles Frend, Michael Balcon, Jack Hawkins, Denholm Eliot, Virginia McKenna and Nicholas Montsarrat, it would be hard to produce a dud. But I think Alan Rawsthorne's score is definitely the icing on the cake, imbuing the narrative with a bleak, resigned stoicism.
These days, far too much film music is usually cliché-ridden and uninspiring, with an emotional palette that rarely progresses beyond happy, sad, in love, danger, funny and mysterious. Indeed, in music, 'filmic' is now a euphemism for overblown, melodramatic and sentimental and when I hear the soundtracks for films like Lord of the Rings, I feel a sense of despair.
I'm not sure exactly why the rot set in, but I'm pretty sure that it all went wrong after Star Wars, but that's a rant for another day.