Night Tide (Horror/Fantasy, 1961)

Night Tide (1961) is an American independent fantasy film, often classified as horror due to its atmospheric dread and supernatural elements. It blends romantic mystery with influences from film noir and psychological thriller, drawing inspiration from Val Lewton's low-budget horror style (e.g., Cat People) and Edgar Allan Poe's poem "Annabel Lee."
Plot
A young sailor named Johnny Drake (Dennis Hopper) arrives in Santa Monica on shore leave and becomes infatuated with Mora (Linda Lawson), a enigmatic woman performing as "Mora the Mermaid" in a sideshow attraction on the pier. Living above the merry-go-round operated by her godfather, Captain Murdock (Gavin Muir), Mora was orphaned and raised with tales of ancient sirens from the Greek island of Mykonos. As Johnny pursues a romance with her, he befriends the merry-go-round operator Ellen (Luana Anders), who reveals that Mora's two previous suitors mysteriously drowned. Haunted by visions of a "Sea Witch" (Marjorie Cameron) and her own belief that she's a siren compelled to lure men to their deaths under the full moon, Mora's psyche unravels. During a scuba dive on a lunar night, tragedy strikes when she seemingly tries to drown Johnny. The story culminates in revelations about deception, obsession, and the blurred line between myth and madness, ending with arrests and farewells as Johnny's leave expires.
Cast
Dennis Hopper as Johnny Drake: A wide-eyed sailor in his first leading role.
Linda Lawson as Mora the Mermaid: The alluring, troubled performer.
Gavin Muir as Captain Murdock: Mora's manipulative godfather.
Marjorie Cameron as the Sea Witch: A mystical figure with ties to occult artist communities.
Luana Anders as Ellen: The pragmatic friend who provides warnings.