Next up, the sonar screen presents images of our cast-members in scenes revealing hard-driving action. First up: Richard Basehart as Admiral Nelson.
Next, we meet co-star David Hedison, as Captain Lee Crane.
In the following card, we meet our creator and producer, Irwin Allen, the man behind Lost in Space (1965 - 1967), and The Time Tunnel (1966-1967) as well.
Finally, our sonar screen disappears, and we go right into the underwater action...