Captain Fathom was an animated television series produced in 1965 by Cambria Studios. Like Cambria's other productions, Clutch Cargo and Space Angel, it was produced in Synchro-Vox. Eighteen 30-minute episodes, all in color, were filmed. The episodes could be broken down into five 6-minute segments in cliffhanger format. Renowned comic book artist Alex Toth was the director. This animated series was broadcast in Italy in syndication in the early 80's under 2 different titles: Avventure negli abissi and Captain Fathom.

While traveling in enemy waters, Captain Fathom and his crew detect an anomalous reading of radioactivity. The submariners investigate and discover a huge bomb lying on the ocean bottom. While Fathom fastens an explosive to destroy the atomic device, his ship is attacked by an enemy submarine. He orders the vessel to flee leaving the Captain and his team of scuba divers behind with a dwindling supply of oxygen in their tanks.