This is a classic for so many reasons, even the writing! Which is odd as it is possibly one of the worst written books I have read (and I've read some stinkers). But in hindsight that is one of the reasons why it is so good. The cliches, stunted suspense, tacked on scenes that explain characters' whereabouts and tie things up as part of an obvious rushed re-drafting process, and the extremely British matter-of-factedness that runs throughout. It all adds up to something special.
The story is slight and uninteresting: Professor Cliff Davenport (awesome name) arrives at a Welsh holiday spot to investigate the untimely disappearance of his nephew and fiancee. There he meets the stunningly attractive and 25 year old Pat Benson (another genius name, sounds like an Eastenders character) whom he falls in love with, with the backdrop of a new species of giant, unstoppable, flesh-eating crustaceans laying waste to the unfeasibly hot Welsh coastline. Click-click-clickety-click.
I jest but it is a phenomenal book. I remember reading it as a pre-teen and lapping it up and I enjoyed it even more some 30 years later. Any book that is the catalyst for such genius as Gath Marenghi's Darkplace is itself genius. 5 more sequel/prequels came after and they managed to get slightly better, writing-wise, but could not replicate the pure awful cheese of this thin epic. At one point, while the army are being ripped to shreds by the sea devils, Cliff and Pat even enjoy a nice breakfast and a smoke before aiding. Truly wondrous.
I dare you to read it!