I love John Wyndham books - The Scent of New Mown Hay one of my faves, the Chyrsalids - great ending - The Children of St. Paul made me gag, no book has ever done that, I loved it.
http://en.wikipedia.org/wiki/The_Kraken_Wakes
The Kraken Wakes
The Kraken Wakes is an apocalyptic science fiction novel by John Wyndham, originally published by Michael Joseph in the UK in 1953 and first published in the US in the same year by Ballantine Books under the title Out of the Deeps as a mass market paperback.
The title is a reference to Alfred Tennyson's sonnet The Kraken, which describes a Scandinavian sea monster.
The Kraken
Below the thunders of the upper deep;
Far, far beneath in the abysmal sea,
His ancient, dreamless, uninvaded sleep
The Kraken sleepeth: faintest sunlights flee
About his shadowy sides: above him swell
Huge sponges of millennial growth and height;
And far away into the sickly light,
From many a wondrous grot and secret cell
Unnumber'd and enormous polypi
Winnow with giant arms the slumbering green.
There hath he lain for ages and will lie
Battening upon huge seaworms in his sleep,
Until the latter fire shall heat the deep;
Then once by man and angels to be seen,
In roaring he shall rise and on the surface die.
Alfred Tennyson
Sounds like the elder god The C'thulu