The ponies journey underwater to Aquastria for the annual race between their seapony cousins and the mermares. Rainbow Dash subs for an injured seapony and competes for the coveted Purple Pearl prize, but she also saves a new friend. Saccharine neon-bright illustrations and a treacly text leave little to recommend in this friendship story, but the ponies' fans will be sucked in. (c) Copyright 2013. The Horn Book, Inc., a wholly owned subsidiary of Media Source, Inc. No redistribution permitted.