The slight son of a Mississippi riverboat captain comes home and wants to see his girlfriend from Boston; her father owns a rival boat.
Banker John James King (Tom McGuire) launches a new boat to put Steamboat Bill Canfield Sr. (Ernest Torrence) out of business. Marion King (Marion Byron) comes home from school in a fast car. Bill looks for his son while Bill Canfield Jr. (Buster Keaton) looks for his father, who is much taller. Bill has Junior's mustache shaved off. Junior sees Marion, and they know each other. Bill tries numerous hats on Junior and buys a white one that the wind blows away. When Bill is laughed at for having Junior's ukulele, he stomps on it.
Junior gets a uniform and comes aboard the old Stonewall Jackson. Marion has to stay on her father's boat. King tells Junior to stay off his boat, and he and Bill push Junior back and forth. Junior pulls a lever, and the boat runs into King's boat, knocking him in the water.
Junior gets a note from Marion to meet her. He pretends to sleep, but Bill makes him take off his uniform and go to bed. Bill wears a large coat and sneaks out. He puts a plank between the boats but falls in. Bill sees that Junior is not in bed. Junior sneaks onto King's boat.
In the morning Bill gives Junior a ticket to Boston. Bill learns that his boat is condemned. He blames King and tries to strangle him. Bill is arrested. Junior carries his bag to the station, but he sees his father is in jail. During rain Junior falls in a mud hole. He takes bread to Bill, who refuses it. Junior gives hand signals and shows him the file. Bill changes his mind, and they use psychology on the sheriff; but Junior drops the tools. The sheriff tries to lock him up, but Junior knocks him out and releases Bill. They lock up the sheriff; but Junior's pants are caught, and the sheriff gets free and sends Junior to the hospital. Bill goes back to jail.
A storm is brewing. Buildings are blown down. Junior's bed is blown into the street. He tries to run in mud against the wind. Junior has many near misses and flies on a tree into the river. Water is filling Bill's jail cell. Junior sees Marion on a building floating by. He grapples it, and she holds on to him. Bill is floating by. Junior uses ropes to move the boat into the jail, rescuing Bill. King's boat sank, and they save him. Marion kisses Bill, who jumps in to save another man.
This farce explores the difficult relationship between
a macho father and his sensitive son, who manages to get over
his clumsiness and save the day.