An imaginative boy and his dog Skipper take an impromptu voyage. Short first-person rhymes tell the story, which begins in the backyard, where splashing in a tiny pool triggers a wish to go to sea. “AHOY!” A ship comes billowing by, and the boy finds himself in the crow’s nest: “I skimmed the deep blue from east to west.” A towering rogue wave brings a nine-headed sea monster. The duo finds refuge on “a coconut isle,” where pirates, a buried treasure, an old crocodile and frolicking mermaids complete the adventure. When they land ashore (i.e., back in the yard), the sea is gone: “There was only the pool that sat on our lawn.” What better way to finish the day than with a warm bubble bath? Heidbreder’s rousing poem is precise, colorful and accessible, a terrific combination for young readers. Denton’s gouache illustrations are similarly pitch-perfect, fun and funny without descending into camp. (Picture book. 4-8)