Ellen Schreiber, . . HarperCollins, $15.99 (160pp) ISBN 978-0-06-008204-8

Life under the sea has become considerably more hip since the days of Hans Christian Andersen's Little Mermaid. In first-novelist Schreiber's updated version, teenage mermaid Waterlilly (Lilly) listens to rock music, wears glittery make-up and frequents the local hangout like most other cold-blooded girls her age. However, unlike the other mermaids, she is not content to date mermen "jocks" from Pacific Reefs High. Instead, she falls for a boy way out of her league, a high school "Earthee" named Spencer, whom she saves from a watery death after a surfboard accident. After the rescue (which ends with a kiss), the story takes familiar turns with Lilly magically sprouting legs and going ashore to seek out the boy of her dreams. When the two reunite, their fondness for each other grows, but Lilly isn't sure if she can give up her fins permanently for the sake of love. As the author alternates between the two lovers' points of view, Lilly, with her adventuresome spirit and rebellious streak, outshines her more mundane Earthdude, and the details of Lilly's ocean life may be the biggest lure to readers. Light on substance but loaded with fun, this revamped romance offers plenty of comical scenes above and below sea level. Ages 9-up. (June)