I remember a movie, maybe from Italy, about 1970, where a German U-boat continues to fight the war for a long time. One of the sailors, when fishing, rescues a little baby who was abandoned at sea. The baby, a girl, is adopted by the crew and called "sea bass". The submarine continues to fight for decades and the girl grows to be a woman. Then the crew decides that she needs a boyfriend, and they capture a young sailor from a sunken ship.
I'm not completely sure that this film belongs to "fantasy and science fiction" genres, because I remember vaguely fights with dinosaurs and sea monsters, but it's possible that I'm mixing several films in my memory, so if someone knows the answer and it's "off limits", please, feel free to move my question. But this film is obviously inspired by the old fairy tale "Snow White and the Seven Dwarves", which does belong to fantasy.