Goofs

When the house is stuck on the railroad track, the whistle of an approaching steam engine is heard, but when the train actually arrives and crashes through the house, it is a diesel engine.

When Tom comes outside after hurriedly dressing to discover the houseboat has broken loose, his shirt is unbuttoned to his waist. In the following shot a split-second later, his shirt is buttoned all the way up to his collar.

During the closing scenes of the film when Tom enters the boy's cabin on the houseboat to try to persuade his children to attend his wedding to Cinzia, amongst the toys on the ledge around the cabin walls can be seen a jack-in-the-box with the clown faced "jack" popped up, but when the camera angle then changes to a close-up of Tom standing in the cabin doorway, the lid of the nearby box is closed and the "jack" is not visible.

When driving in the open convertible, there is no wind in their faces or hair.

When driving to the house, singing in the car, they are pulling a small trailer with their belongings. However, the shots from the front angle (with the rear screen process) show no trailer behind them.

The water does not move in any shot in the galley or other room in which there is a view out the windows.

The harmonica that Cinzia wins for Robert is labeled "ECHO". An echo harmonica has 2 reeds for each note, each reed slightly detuned sharp and flat to provide a tremolo effect. The sound when Robert is playing this instrument is of a normal harmonica.

During Cinzia's first visit to Tom's apartment, at one point he is adjusting the sofa bed. As the two converse, the camera moves closer to them, and the shadow of the moving camera can be seen on Cinzia's dress.

Tom's apartment is in Washington, D.C., but when he's driving his kids to the concert at the Watergate, he approaches the area from the Virginia side of the Memorial Bridge, which is the opposite direction from which he would logically be coming.