Two teenage girls discover a mermaid in their beach club's swimming pool.
In a dreary Florida beach resort village, luscious-limbed lifeguard Raymond is the main attraction for girls. Teenager buddies Claire and Hailey became experts on him by observation, but never dared actually approach him, and after this closing summer season will be separated as one's parents move to Australia. Then they find a storm washed up in a pool a sassy mermaid, who promises them a wish if they help her prove to Neptune love exists, and Raymond is the only creature resembling a love-god.
Two twelve year old girls are in love with a dilapidated beach club near their home. After a huge storm, they discover Aquamarine, a mermaid, in the pool of the club. Aquamarine then falls in love with the cute, young lifeguard who and begs the girls to help her set up a date with him.
After a vicious storm , half the ocean washes into the beach club swimming pool. Two teenagers, Haley and Claire, discover a mermaid in the pool. She tells them that she needs to find love in three days, and they agree to help her because helping a mermaid means you get a wish, and they decide that they can use their wish to try and stop Haley from moving to Australia.
- Two teenage best friends, Claire (Emma Roberts) and Hailey (Joanna "JoJo" Levesque) regret that they will be separated in five days, since Hailey has to move to Australia because of her mother's job. One night, after a violent storm they find a mermaid, named Aquamarine (Sara Paxton) in the swimming pool of their beach club. The girls are frightened at first, but then curious. They start to talk with Aquamarine and promise her they will be back in the morning.
When they return, they find Aquamarine in the beach's snack shack, but with a human body instead of a mermaid's. Aquamarine tells them she can assume human form on land during the day if she does not get wet. Claire and Hailey befriend Aquamarine, who tells them that she came to land to find love, an idea she knows nothing about, but desires desperately. She tells them that she made a deal with her father: if she finds love in three days, she will not undergo an arranged marriage. She immediately notices a handsome lifeguard named Raymond (Jake McDorman) and enlists the help of the two girls to win his heart in return for the granting of a wish. The girls see their opportunity to keep Hailey from moving and immediately start helping her.
Claire and Hailey's rival a spoiled, rich girl, Cecilia (Arielle Kebbel) tries her best to stop them, but fails. Also prominent is an eccentric, compassionate caretaker, Leonard, who rescues Aquamarine from public discovery. Eventually, it is not Raymond that convinces Aquamarine that humans can love, but Claire and Hailey, who are willing to give up their wish and their lives in the aiding of a friend. Raymond and Aquamarine share a kiss and promise to meet up again in the future, Raymond promises he'll wait for her. Hailey and Claire get their wish from Aquamarine, but decide not to use it until later.But it is mentioned that they plan to use it to make sure all three of them can visit each other every summer.