The Kraken Wakes / John Wyndham

It started with fireballs raining down from the sky and crashing into the oceans' deeps. Then ships began sinking mysteriously and later 'sea tanks' emerged from the deeps to claim people... For journalists Mike and Phyllis Watson, what at first appears to be a curiosity becomes a global calamity. Helpless, they watch as humanity struggles to survive now that water - one of the compounds upon which life depends - is turned against them. Finally, sea levels begin their inexorable rise... The Kraken Wakes is a brilliant novel of how humankind responds to the threat of its own extinction and, ultimately, asks what we are prepared to do in order to survive.