Diver Dan was not your normal weekday afternoon entry.
A mix of puppets and 2 actors composed this series, produced for syndication and distributed by England's ITC Entertainment. Diver Dan (Frank Freda) roamed the sea in search of adventure. If it was being teased that Minerva, the mermaid, was meant to be Dan's love interest, she certainly seemed as though she wanted to play hard to get.
Allen Swift narrated and voiced virtually all of the puppets. Producer Louis Kellman might be better known for his work with NFL Films, rather than this short-lived series. I must confess that I had not seen this before today. I guess now you know why they didn't try this type of show again.
The first four episodes are blocked together in the following clip:
Swift was the most experienced performer on the show, but there wasn't much he could do to save this from being consigned to oblivion, as this was off the air by the time I was ready to watch television as a toddler.