This author-illustrator team add nautical nighttime bliss to their ever growing roster of transportation-related beddy-bye books (Where Do Jet Planes Sleep at Night?, 2017, etc.).Even motorized ocean denizens have to go to bed sometime. A wide range of grinning, anthropomorphic boat caregivers call in their little ones against richly painted scenes of skies, stars, and seas. Initially the book focuses on parent-child boat pairs, but as the story progresses readers will see sleepy-eyed adult ships bedding down on their own. The book covers a wide gamut of vessels, including the titular speedboats, canoes, subs, tugs, and aircraft carriers. Meanwhile, gentle rhymes lull readers with comforting couplets (that occasionally force scansion). "Where do cruise ships sleep at night / once their ports have all been reached? / Do these boats begin to dream / of their own trips to the beach?" With each new boat the sun dips lower until readers are left at last in a home where a child's toy boats perch on the edge of the bath at the end of a long day. As with the previous books in the series, each image incorporates a little white mouse, playing peekaboo with readers in each and every spread.Seaworthy, sleepworthy, bedtimeworthy fare. (Picture book. 3-6) Copyright Kirkus Reviews, used with permission.