The boat bringing the wedding party to Harper's Island is the HMNZS Tarapunga. She was a modified Moa class inshore patrol vessel of the Royal New Zealand Navy (RNZN) and was purchased by North American owners after decommissioning.
Cousin Ben Wellington, who dies at the beginning of this episode, appears in the internet show Harper's Globe.
At the beginning of the episode it is revealed that Harper's Island is 37 miles off the coast of Seattle, Washington and is only accessible by watercraft.
The title of this episode, which is Whap, refers to the sound made during Cousin Ben's dismemberment by the ship's propeller.
All 13 episode titles refer to sounds made by the deathblows of various weapons used in that episode.
Goof: In the opening scene, a taxi pulls up to the dock area with the misspelled lettering on the door saying, "Bay area Taxi, Seattle, Washingtion".
Cousin Ben Wellington: He was tied to the bottom of the ship and was killed by the propeller
Uncle Marty Dunn: His body was sliced in half by the killer using a sword.
Actors Katie Cassidy, Jim Beaver, Gina Holden and Chris Gauthier have all previously appeared on Supernatural, although the four never appeared together all at once.
Trish Wellington: (looking down on Sully, Danny, and Malcolm) You know what I love about those guys?
Shea Allen: They bring their own beer?
Trish Wellington: No. That they love Henry as much as I do.
Trish Wellington: (In bed) Was I loud?
Henry Dunn: What? No!
Trish Wellington: Oh my God, I was loud.
Henry Dunn: No!
Trish Wellington: Oh my God, I was so loud!
Henry Dunn: It's OK, it makes me look really good.
Danny Brooks: Uncle Marty's what, 50? He's not married, no kids, and here he is trying to tap some hot thing half his age. Come on!
Malcolm Ross: Oh, oh, okay Oprah. So in what world does that make him not a superhero?
Chloe Carter: Am I the only one who thinks that men and women can't just be friends?
Visual Effects Provided By: Entity FX
Post Production Sound: Smart Post Sound
Main Title Design: The Picture Mill
Post Production Services: Technicolor, Vancouver; Modern Videofilm, Inc., Los Angeles
Although Claudette Mink (Katherine Wellington) appears in this episode, she has no lines.
1. Love Remains The Same by Gavin Rossdale.
2. I'm Not Over by Carolina Liar.
3. Erase Me by Star Ghost Dog.
4. Transfer by Collide.
5. Ave Maria by Franz Schubert.
Original International Air Dates:
Norway: Sunday, April 19, 2009 on TV2Zebra
Australia: Sunday, May 10, 2009 on Ten
Ireland: Monday, June 8, 2009 on RTE2
Poland: Sunday, June 14, 2009 on AXN
Germany: Wednesday, August 26, 2009 on ProSieben
Finland: Thursday, September 3, 2009 on Nelonen
Czech Republic: Wednesday, January 13, 2010 on Barrandov
Slovakia: Sunday, January 8, 2012 on JOJ
Cal: (to Chloe after surprising her with a sailing excursion) My bounty is as boundless as the sea, my love as deep.
This quote comes from William Shakespeare's famous star-crossed lovers tale Romeo and Juliet.