Ask anyone about Japanese anime from the 60's, and they're bound to remember Gigantor or Speed Racer right off the bat, largely because both were revived in later years here in the US.
However, they weren't the only anime that came here back in those days. Japan also gave us The Amazing Three, Astro Boy, and our next subject, Marine Boy.
In essence, Marine Boy was Japan's juvenile answer to Marvel's Sub-Mariner or DC's Aquaman, both of whom would make their animated debuts shortly after Marine Boy bowed in Japan. Over the course of a four year period (1965-9), there would be three series, with as many titles, produced in Japan, but Seven Arts, at the time a partner with Warner Bros., went with the all-encompassing umbrella title of Marine Boy to keep things simple.
Marine Boy was a teenager, presumably between 13-15, whose abilities were enhanced by his father's inventions. He had a pet dolphin, Splasher, as a sidekick, and there was a prospective romantic interest in a young mermaid, Neptina. Corrinne Orr (Speed Racer) voiced both Marine Boy & Neptina, while her Speed Racer co-star, Jack Grimes, was Splasher and a few other characters. Grimes would later be the voice of Jimmy Olsen for Filmation's New Adventures of Superman.
Marine Boy was included on Warner Home Video's Saturday Morning Cartoons: The 1960's, Volume 1 due to the Seven Arts connection. Aside from that, it's nothing really special. The episode on the DVD, "Battle to Save the World", is not available on YouTube at present, but the intro to the show is.......
Neptina was reportedly a pre-teen, but for modesty's sake her long hair covered her developing cleavage just the same.