Undersea Kingdom 1936 is a Republic Pictures film serial released in response to Universals Flash Gordon. It was the second of the sixtysix serials made by Republic. In 1966 scenes from the serial were edited into a 100minute television film titled Sharad of Atlantis.
The plot revolves around the main character Crash Corrigan trying to stop an evil tyrant ruler of Atlantis from conquering the lost continent and then the entire upper world.Lieutenant Crash Corrigan, in his last year at Annapolis, is invited by Billy Norton to visit his father, Professor Norton, after a wrestling match. At their house, the professor is demonstrating his new invention, which can detect and prevent at short range earthquakes, to Diana Compton and his theory about regular tremours from the area where Atlantis used to be. ........
Source: Wikipedia