1, 2, 3… Splash

Allen Bauer is a New Yorker who was saved from drowning as a boy thanks to a young mermaid. 20 years later, he returns to the same spot and falls into the sea again, only to be rescued once more by the same mermaid. Confused by what happened, Allen goes back to New York, but the mermaid decides to look for him. The two eventually find each other and fall in love, although he is unaware of her secret.