The series returned with the same crew in 1969, retitled Undersea Boy Marin (Kaitei Shonen Marin), for further adventures about Marine, now equipped with an underwater boomerang, a hydrojet, and a mermaid girlfriend Neptuna (Neptina in the U.S. version). It lasted for a total of 78 episodes, including some recycled from the previous series. Broadcast on TBS, the entire run was not seen until 1971, when it was shown on Nippon TV.
During all this confusion, the series was already doing well in the U.S., where it premiered in 1966. With three episodes dropped for violence, Marine Boy still incurred the wrath of the National Association for Better Broadcasting, which claimed it was "one of the very worst animated shows. Child characters in extreme peril. Expresses a relish for torture and destruction of evil characters." Strangely, no mention was made of Neptuna's strategically placed hair, which obscured the fact that she spent the entire series topless, or that the three "violent" episodes were considered harmless enough to be screened when the series was rerun during the 1970s. Though obscure today, Marine Boy was a popular anime in its time, outperformed in the 1960s only by Speed Racer in the U.S. and the first anime to achieve any degree of success in the U.K., though its Japanese origins were occluded. According to popular myth, decades later, the same BBC that screened Marine Boy in the 1970s would turn down Pokémon, claiming that "nobody was interested in Japanese cartoons." In another spurious assertion, the father of the five-year-old Jonathan Clements claimed that "Marine Boy always eats his greens," though none of our Japanese sources support this.


