Elizabeth Allen’s Aquamarine is a movie for, about, and, judging from the premise, dreamed up by 13-year-old girls. Claire (Emma Roberts) and Hailey (teen-pop sensation JoJo) are best friends who lounge on the beach all day crushing on lifeguard Raymond (Jake McDorman), savoring the last few days of summer, and dreading Hailey’s impending move to Australia that will tear them away from each other. Then a storm washes the titular mermaid (Sara Paxton) into their swimming pool, and suddenly the girls have a new friend and a secret to keep. Apparently, mermaids grant wishes to people who help them, so the girls grudgingly play matchmaker for Aquamarine and Raymond to earn a wish that will keep Hailey from moving away. Sappy lessons learned and surprisingly snappy dialogue ensue, along with unintentionally funny lines such as, “Are you staring at my tail? Do you want to touch it?” Oh, and there are fish puns. Lots of fish puns. The creepy-old-man-who-turns-out-to-be-a-nice-guy character (Bruce Spence here) is beamed in from Home Alone, and before you know it, there’s a happy ending. Maybe in the sequel they can give a unicorn a makeover.