I saw this episode numerous times on the tape, but had always been curious if any more existed. Last year in the States, I was happy to see a DVD for only $5, which contained almost 2 hours of episodes! Out of 104 episodes, apparently only 40 or so are known to exist. I've always loved the early days of TV, when there were no budgets and people had to be creative - in Diver Dan, they don't need CGI or expensive underwater photography, they just filmed it through a fishbowl!! Ernie Kovacs would have been proud (although he probably invented the technique himself).
Also on that old VHS tape was a show called SUPERPUP! No one seems to have uploaded that in its entirety yet (although it's in the public domain), but there's this small clip, which puzzled me because the tape I had was in black & white, and this is in colour! This show was not quite so charming as Diver Dan - in fact, it never made it past the pilot stage. And I don't get why Sgt Beagle was a Basset Hound???
I guess I just wasn't made for these times. Give me old movie serials, cheap kiddie shows, and lo-fi music over all this CGI-Pixar stuff any day!!!!