Help Velma and the Hex Girls solve a riverboat ghost mystery in this officially licensed picture book featuring Scooby-Doo, Shaggy, Daphne, and Fred. The Mystery Inc. gang has no idea that their class trip will include a visit from the ghostly Captain Barnacle. And when Shaggy, Scooby-Doo, Daphne, and Fred all become seasick, it's up to Velma to try to track down the passengers' stolen backpacks and the Hex Girls' musical gear! Could...