Voyage to the Bottom of the Sea - Season 4 - Eps 26: No Way Back
Seaview experiences a sudden power overload and blows up, killing all hands aboard. When Admiral Nelson (who was at the Nelson Institute at the time of the accident) hears of the destruction of the Seaview, he gets an impossible to refuse offer from Mr. Pem (who survived from A Time To Die): in exchange for the use of the sub's nuclear reactor, Pem will transport Nelson back in time to before the explosion which destroyed Seaview. Once back in time, Pem renergizes his time travel device and brings the sub back even further in time to the American Civil War. Before the crew has time to absorb this, the ship is boarded by Major General Benedict Arnold! Now Nelson has to stop Pem's far-reaching plan to take over the world and avoid the explosive disentergration of Seaview.
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