Aside from the show's propensity to overly romanticize these creatures at the beginning of the program (calling them 'mermaids' was pretty goofy), this is an exceptionally good episode of "The Undersea World of Jacques Cousteau". It shows these marvelous creatures in their native habitats in various places in Florida, including the St. John's River on the Atlantic coast and Crystal River on the Gulf side of the state. You learn about how threatened* the creatures are from boat propellers and you see Cousteau's team and others interacting** with these adorable creatures. It's all very compelling and very well made--and well worth seeing.
*Fortunately, the manatees are doing GREAT since this show debuted and they are no longer considered threatened. I often see them when I am fishing or boating.
**Most of the interactions they show in this program (especially the public interacting with them) are STRICTLY ILLEGAL today. While there are places where you can legally snorkel in the same rivers with them, you are NOT allowed to touch them, grab them and a lot of the other stuff you see in the show. This isn't meant as criticism but an acknowledgment that laws about this have been instituted since the early 1970s.