- Actor Allusion: The same year, Stephen Rea starred in the film Nothing Personal, about a mythological sea creature (in this case a mermaid).
- California Doubling: Averted. The film was shot on location in Cork.
- Dyeing for Your Art: Alicja Bachleda is normally brunette, but lightened her hair to blonde to play Ondine.
- Fake Nationality: Alicja Bachleda is Mexican-Polish playing an apparently French creature from Scottish mythology. She's really a Fake Romanian.
- Production Posse: Stephen Rea has starred in many Neil Jordan films such as The Crying Game, The Company of Wolves, Interview with the Vampire, Michael Collins, The Butcher Boy etc.
- Reality Subtext: Syracuse and Joanna get married at the end, Joanna essentially becoming Annie's stepmother. Colin Farrell and Alicja Bachleda had a baby together shortly after the film.
- Romance on the Set: Colin Farrell and Alicja Bachleda.
Trivia / Ondine