
Television sitcom The Love Boat has the high-concept setting of a luxury cruise ship, where each episode follows the antics of its crew and rotating guests. As can be inferred from its title, a lot of the stories feature romances of one kind or another, and can vary in tone from lighthearted to melancholy.
In season 7, the storyline "A Fish Out of Water" features the romantically hapless Alan Bundy (Ed Begley Jr.), who has joined the cruise in the hope of finding love, but has such trouble talking to women and is mainly an awkward though well-meaning guy. While exploring the depths of the ship he finds the storage room of live specimens that are being sent to the Oceanic Institute. Among these specimens is a mermaid named Coral (Mary Crosby), who immediately charms and is charmed by Alan.
The pair have an instantaneous connection, and spend what little time they can together. Alan immediately clocks that it's wrong for a mermaid to be kept in captivity, and is ready to say goodbye to her, but it's Coral who wants to spend more time with him. At Alan's urging, Coral is returned to the ocean, only for the whole romance to turn out to be Alan's dream after passing out earlier in the cruise. Though not long after, Alan meets a fellow passenger on the ship who looks awfully familiar...
Thank you to Jenni for letting me know about this episode!