Due to the film having a generous helping of lovely young ladies in various states of undress, the U.S. release was predominantly at military bases.
First film lead role for Dianne Webber. Before getting into acting, she was a Playboy Playmate in 1955 and 1956, and a proud lifelong nudist. Because of her voluptuous full figure and willingness to show it off, she became a very popular nude model in several popular men's magazines. She loved being naked and sharing her body with the world.
In 1967, Diane Webber would again don the fiberglass fin in "The Mermaid" episode of Voyage to the Bottom of the Sea (1964).
The original version has the mermaids looking like mermaids, and for its time, the costumes are fantastic. The "R" Rated version, which is the only one remastered on the Psychotonica DVD, has naked women wearing store-bought flippers. But the original also appears on the DVD under EXTRAS, only it's far grainier.
The film was theatrically reissued in the United States in 1965, under the alternate title of The Aqua Sex. That version featured newly filmed nude footage created by the film's original director, John Lamb.