The model and interior sets of the submarine cost producer Irwin Allen $400,000, so he was naturally quite keen to get some further use out of them. Since the film was a hit, he was able to convince ABC-TV to turn it into a series, which became the longest-running one he ever had.
Del Monroe appeared in the original film as Kowski as well as the regular character with a similar name, Kowalski, on Voyage to the Bottom of the Sea (1964).
During production, Irwin Allen asked the Navy for advice to help in making the film. However, the Navy refused because its nuclear program was just beginning in 1961 and was top secret. They didn't want any information getting to the Soviet Union.
The design of the "Seaview" model took full advantage of hydrodynamics. In the the underwater scenes, it was simply pushed into frame by an off camera diver and allowed to glide freely by itself. This made the scenes quite realistic, although in one it can be seen losing momentum and arcing downward a tiny bit just as the scene cuts. In surface scenes, it was pulled by thin wires.
Irwin Allen: The voice-over for the newscasts that crew members watch, detailing the burning forests, etc.