Why narration like a radio play? Constant description of shown actions!
Why did the producers always have Mike Nelson/Lloyd Bridges constantly NARRATING things we could SEE ON SCREEN! Lol!
"I dove down (show diving man), cut the rope with my knife (show man cutting rope), dropped my weight belt (show man dropping weight belt), and swam to the surface (show man swimming to surface).
It reminds me a lot of "The Six Shooter", James Stewart's cowboy radio drama, where he narrated every single movement of the day in excruciating detail, it could take ten minutes to eat dinner and drink a coffee during a 15 minute show! /s. But at least Jimmy had the excuse of being on radio!
It's quite bizarre to watch a scene in current time, being described at the same time in past tense narration.
Now that I write this, a thought comes to mind that this is mainly during the underwater sequences, and maybe the producers thought that having no technology at the time to talk underwater, it would be too boring to just watch actions with a music bed underneath it.
But even the rest of the show is written with tons of narration, rather than character dialog to explain plot points. Maybe it was a style at the time.