Continuity mistake: The scarf around Ellie's neck (in the car) repeatedly changes. Make up your mind, love.
Continuity mistake: When the bus is about to pull out of the station Ellie places her suitcase on the overhead rack, and in the next exterior shot we see the license plates at the front of the bus, then it cuts to a closeup and one of the plates has changed from "F8274" to "G8278." (00:08:40)
Continuity mistake: At the start, when Ellie rushes out of the ship's cabin she's wearing dark flat type shoes, but when Ellie climbs onto the deck railing she's wearing high heel sandals. (00:03:10)
Continuity mistake: Before the wedding, while Mr. Andrews is comforting Ellie she pulls a handkerchief from her father's pocket. When Andrews tells Ellie that she's changed, the handkerchief is in Ellie's left hand as she grasps her father's hand, but in the next closeup the handkerchief has vanished even as Ellie is still holding her father's hand. (01:32:20)
Continuity mistake: While Ellie is standing behind the first bus (#204) when it's filling up on gas at the rest stop her suitcase is stolen, and as Peter starts chasing after the thief note all the license plate numbers including "173-909" and "G8271" at the back of the bus. Later, when Ellie and Peter are on the second bus (#217) as it drives into the muddy ditch, in the closeup we see license plate numbers "173-909" and "G8271" (and more) which are the same as the first bus they were on. (00:08:40 - 00:46:40)