Like The Mole People, Unknown World and The Abyss, The Incredible Petrified World (IPW) defies sci-fi conventions by taking place entirely in inner space. Also like Mole People and Unknown World, inner space seems to have been built for human habitation - not only are the cave networks the perfect size for humans to walk upright in, the absurd Cyclotram of the unknown world even has a nicely graded (though bumpy) road to travel along while drilling through solid bedrock.
The only resemblance between this film and The Abyss is the underwater setting. IPW was made with less than a fraction of The Abyss' budget and the most talented actress in the film (Coates) was not paid. The film proceeds with mostly character-actors, and little to no character development.
Four people - a professional diver, two oceanographers and the stereotype female reporter - man the first deep-sea submersible diving bell (ya, this technology was already somewhat obsolete by the 1950s and the Navy was doing far more interesting things but who cares) on its first exploratory mission. Predictably, something goes wrong. But soon enough the crew finds itself in an underwater maze of caverns complete with fish ponds, potable water, a monitor lizard and a vaguely menacing hermit with extremely bad hair.
Putting all the absurdities aside (which is asking a lot), the plot is at least different and does take a few unanticipated turns. The terrestrial portion of the plot - focusing on Carradine as the philanthropic engineer sponsoring all of this - is actually more or less believable and interesting. But any value this plot adds is easily balanced by the laughable goings-on down below - especially the unnecessary and ridiculous hermit subplot.
All in all, I think this film deserves a better rating than it has here on IMDb, but I was seriously reconsidering my rating after I read about Ms. Coates' difficulties resulting from this film.
Recommended for B-sci-fi fans. AAAC (avoid at all costs) for everybody else.
