Miss Mackle's class is learning about their ancestors, and everyone just found out that Ida's great-great grandmother sailed on the Titanic-and lived to tell about it. Miss Mackle decides to take the class on a riverboat ride to help them imagine what it was like to travel on the high seas like their ancestors did. Harry and his friends are so excited-it's going to be the perfect field trip. All aboard! Room 3B is setting sail!