"A one-hour commercial presented as entertainment:" That's what Disney's competing movie producers called episodes like this. In truth, it was all commercials. If the show wasn't pushing 20,000 LEAGUES UNDER THE SEA, like this episode, or some other Disney movie, it was showing clips from older Disney cartoons, keeping them current for rerelease into the theaters, or letting you know about the wonders of Disneyland. It was a fabulous example of cross-marketing. Walt understood, though, that he had to make the TV show as interesting as possible, if only to keep those people watching.
And he did. This episode offers some wonderful undersea footage from around the shooting of the picture. It's narrated by Winston Hibbler and children who saw this on their televisions in black & white would be anxious to see it in color on the movie screen. Their parents, too.