At River Junction, Mississippi, Mr. J.J. King launches his new passenger steamboat the "King," to compete with the "Stonewall Jackson" paddleboat, an old tub, owned by Steamboat Bill Canfield. When challenged by Mr. King, Steamboat Bill vows never to give up his ship, even if he is the only passenger sailing on it. Meanwhile, a telegram arrives from Steamboat Bill's son Willie. Willie, who hasn't seen Bill in a very long time, is coming from a Boston college, and he'll be wearing a white carnation, so he'll be recognized immediately.
At the train station, Bill and his first mate Tom await Willie's arrival. It just happens to be Mother's Day, and the passengers disembarking from the train are wearing white carnations in their lapels. Willie is nowhere to be found. As the train pulls away from the station, a small, young man sporting a pencil-thin mustache, a beret, plus fours, an argyle sweater and a white carnation, stands on the opposite side of the tracks. Doubting that this could be his son, Bill doesn't even ask him his name. Willie, on the other hand, goes from man to man seeking his father. When he accidentally bumps into a baby carriage, Willie entertains the crying infant by playing his ukulele and prancing wildly. Watching this comical scene, Bill glances at the young man's luggage tag and learns the truth about his identity. An awkward reunion between both the disbelieving father and son takes place, with Willie sensing Bill's disappointment in him.
Bill decides to change Willie's image a bit before returning to the boat. At the barber's for a shave and a trim, Willie meets up with Kitty, his college sweetheart, and daughter of Mr. King. A new hat, and some work clothes chosen by Kitty, complete Willie's new look, much to the chagrin of his father. Once on the boat, Bill tries to instruct Willie in the task of sailing the vessel, but Willie causes a number of mishaps that almost wreck the ship and make a wreck of Bill at the same time. Seeing Willie's interest in his competitor's daughter, Bill forbids Willie to see the girl. Late that night, Willie sneaks out to meet Kitty against Bill's wishes. When Bill finds out, he decides to send him back to Boston.
Next morning, Mr. King has the Stonewall Jackson condemned claiming that it would sink. Bill gets into a tussle with him, and is arrested. Just as Willie is leaving for Boston, he spots Bill being hauled off to jail. Despite their differences, Willie decides to stay and help his father.
The day proves to be wet, windy, and stormy, so Willie, equipped with an umbrella and loaf of bread, tells the jail keeper that his father needs bread to eat. Bill doesn't quite catch on to Willie's clever escape plan until it's too late, and the soggy loaf releases all its hidden tools onto the floor. Willie, now on the verge of being locked up too, knocks out the jailer and springs his father. Bill escapes, but Willie gets in trouble, when he returns for his umbrella. Watching in horror as Willie is knocked unconscious and taken to the hospital, Bill turns himself in to the jailer.
As the fierce storm rages on, the hospital is blown away. Willie's bed becomes mobile sending him on a wild ride through the town. As it comes to rest in front of a house, Willie hides beneath it for safety. A man in the house jumps from a second story window and lands on the bed, crushing Willie underneath. Dazed, Willie stands up just as the entire front of the house falls, but he escapes harm through the open, top floor window. While the town is ripped apart by the ferocious winds, Willie desperately looks for a safe haven. He ends up in a demolished theater, is hit on the head by a falling sand bag, and gets tangled in the magic tricks and stage props. Frightened, he flees as doors fall over him and houses crumble about him.
The force of the storm causes the jail to slide into the river, trapping Bill inside his cell. Willie notices that Kitty is clinging to the roof of another floating building, so he races to save her. Once she is safely on land, Willie uses the Stonewall Jackson to break through the sinking jail, releasing Bill and keeping him from drowning. Mr. King also is rescued by Willie, and because of the circumstances, a truce between the rivals takes place. Willie quickly jumps back in the water again, to the surprise of the others, but this time he returns with the minister. — Janice Agnello