I saw this movie in the early 2000s I think. It’s a fairly old-ish movie. There’s a creepy middle-aged man who tries to seduce a tween girl and follows her around like a predator. Later, the whole family, the father the mother and the daughter are on a boat and the creepy predator man kills (or so he thought) the father and locks and ties up the mom and the daughter. But in the end the father is not really dead and the mother ends up killing the creepy guy and he drowns in the sea. I have vivid memories of it, but I guess it’s not a very popular movie since no one seems to know it.