In this 60s show, the first of four Irwin Allen science fiction productions, the advanced submarine Seaview takes on all kinds of missions for the American government. Under the leadership of Admiral Nelson and Captain Crane, the Seaview takes on a variety of gritty real-world missions with spies, missile launches, deep-sea exploration, etc.
Unfortunately, then Batman caught on and Allen decided that camp and far-out science was the way to go. Increasingly, episodes dealt with mind control, aliens, werewolves, evil puppets, monsters in cheap-looking rubber suits, etc. After three more seasons, the show came to an end due to low ratings.