Voyage to the Bottom of the Sea - Season 4 - Eps 19: Secret of the Deep
Naval ships have been disappearing, and Seaview is on a hunt for the undersea installation responsible. They find a sea-lab that is not only well-armed but surrounded by overgrown and ferocious sea-creatures. To complicate matters, the guest expert aboard is a traitor. Various "dangerous denizens" of the deep from earlier episodes reappear here, thanks to re-used footage: there's a whale, and one of those globular-eyed bottom-dwelling monsters seen in such episodes as "Deadly Creature Below".
About Voyage to the Bottom of the Sea

Title: Voyage to the Bottom of the Sea
First Air Date: 1964-09-14
Last Air Date: 1968-03-31
Status: Ended
Rating: 7.7/10 (from 121 votes)
Language: EN
Seasons: 5
Total Episodes: 110
Network: ABC
Genres: Action & Adventure, Drama, Sci-Fi & Fantasy
Production Companies: Irwin Allen Productions, 20th Century Fox Television
Synopsis
Join the crew of the Seaview aboard their super high-tech submarine, where no mission is too dangerous and no threat is too deadly, be it enemy agents, mad scientists, deadly sea creatures, or impending nuclear disaster.
Cast

Richard Basehart
Adm. Harriman Nelson

David Hedison
Captain Crane

Terry Becker
Chief Sharkey

Del Monroe
Kowalski

Paul Trinka
Patterson

Richard Bull
Doctor

Robert Dowdell
Chip Morton