Jessica Simpson was originally offered the role of Aquamarine, but was forced to turn it down due to scheduling conflicts.
Shipped to cinemas under the name "H2O".
The scene where Hailey is swimming with dolphins was filmed at Sea World and Joanna 'JoJo' Levesque was afraid of swimming with them.
Joanna 'JoJo' Levesque's film debut.
JMB FX Studio produced the mermaid tails for actress Sara Paxton. The tails were sculpted over Sara's body cast. Foam and silicone skins were produced for 4 tails, each tail was covered in over 5000 scales. A fully cable controlled tail was also produced for the more complicated and subtle moves of the fluke that the suit tails could not perform.
Sara Paxton's mermaid tail weighed over 100 pounds and was approximately 8 feet in length.
Only 5 American actors appear in the film - Emma Roberts, JoJo, Sara Paxton, Arielle Kebbel and Jake McDorman. The rest of the cast are all Australian.
Sara Paxton would have a 4am call-time every morning as she required 2 and a half hours to get her hair and facial make-up applied, and then another 2 and a half hours to have her tail fitted.
To play the part of Aquamarine required for Sara Paxton to do a month of intensive swimming lessons beforehand.
In the scene where Hailey and Claire meet Aquamarine in the pool, Aquamarine says "I've never been this close to a human before." This is a direct quote from Disney's "The Little Mermaid." When Sarah Paxton says this line, her voice in fact sounds freakishly like Jodi Benson's, who provided the voice of Ariel in "The Little Mermaid."
EASTER EGG: On the special features menu, on the fourth page, go all the way down the list to the "Kickin' it in on set" featurette, then click right and highlight the outline of a starfish. Selecting this will take you to a short video of Emma Roberts, Joanna "JoJo" Levesque, & Sara Paxton interviewing guys in Australia about dating girls.
On an honor board in the main hall of the beach club, there are names of people in the crew, including the costume designer, Sally Sharpe.