I knew that, at the end of his career, Carradine was pretty much a hack for hire, showing up in awful stuff like The Tomb. But, it seems, his willingness to overlook quality for employment, dates back a lot further, at least as far as this 1957 D-movie, which was still only good enough to sit on the shelves for three years before sneaking out on a double-bill with another Warren film, Teenage Zombies. This shameless barrel-scraper has Carradine as Professor Wyman, whose exploratory diving-bell breaks free. The four occupants, bail out, but end up surfacing in a cave, with no apparent exit to the outside world. Fortunately, they are able to locate enough provisions to live, and long-term survival is clearly possible, as they bump into a sailor has been marooned there for 14 years. However, their timing sucks, as the dormant volcano that somehow feeds oxygen into the eco-system is apparently on the edge of erupting.
Man, this is staggeringly uninteresting, Maybe it was different at the time it came out, when people floating lackadaisically through murky water was still fascinating, and an unconvincing diving-bell mock-up the stuff of thrilling cinema. Though I suspect the fate this production met, suggests even audiences in those days were unimpressed. Hard to be sure whether things get better or worse once they're meandering round the cave, with the dramatic high-point reaction shots of the four seeing a reasonably-large lizard. When even the arrival of a gratuitously threatening volcano can generate not even the slightest degree of interest. a film is in serious trouble. Although, in this case, that has been apparent from virtually the start. Rarely has the word "incredible" ever been less justified in a film's title.