Hanna-Barbera Scooby-Doo...Mystery Comics #29

The gang are riding down the Mississippi on the Moonglow, a paddle-wheeler bought by Mr. Hull, Fred's junior high school history teacher. \"Skipper\" Hull tells them he wouldn't have been able to afford the riverboat, but the Moonglow is supposed to be haunted and he could only get three men to crew: Hank, Wilson, and Paul. While Shaggy and Fred suit up as crew and Daphne and Velma don period dresses, one of the original crew informs Spider in the boiler room that the kids are staying on board. On his transistor radio Fred hears a newscast that a \"gangland boss has escaped from prison.\"