The Monsters

Like others here I recall seeing this age 9 and having to hide behind the sofa, along with begging not to be sent to bed. Was it an early environmentalists subject ? The baddies were using a submarine chariot to dispose of toxic waste by sinking drums of the stuff into a deep lake (or loch, not sure where it was supposed to be). The monsters rebelled by clobbering it and killing the divers. At the end the monsters came out of the lake & demolished the control centre, the memory of monster claws piercing the window and Venetian blind is still very clear.

By the way the monsters came out of the water at the end I guess they filmed this by having a model monster & pulling it up on a slipway, so somebody must have had a lot of fun !

What a shame it's lost.