Have you got the answer to Hydronaut's question?
A forgotten aquatic based sci-fier from an era that loved them, Andrew Marton's film isn't extremely bad exactly, it's just that it plods along without ever really reaching exciting heights.
Cast features Lloyd Bridges, Brian Kelly, Shirley Eaton, David McCallum and Keenan Wynn, who are tasked with traversing the world's ocean beds to plant sensors that will warn mankind of impending earthquakes. A tricky task for sure, especially after we have been told at the start that the depths of the ocean is more inhospitable than anything in space.
The science is of course nutty, as is the effects and photography work on show. Much of the film is taken up with talk, be it sci-fi boffins or heroes in waiting, or a burgeoning romance (Eaton locked in a submarine with a load of men, what a shock!), the chatter promises more than the film ultimately delivers. The expected perils arrive, a couple of beasties of the sea, some submarine damage threatens to scupper our heroes, which asks us to hold on to see how it will pan out. Thus who will survive etc? The end of the world core of the story, the earthquake science et al, is interesting to a cerebral degree, but it plays out like a screenplay that Irwin Allen read and threw in the trash can because it wasn't exciting enough. 5/10