Revealing mistake: While Lucy and Vivian are on the boat we can see the two long tracks on the floor in the boat's galley, so when Viv falls asleep in the chair she brought from home, the chair legs are able to keep gliding along the tracks on the floor from one side to the other. (00:19:45)
Revealing mistake: The boat is quite rocky, causing their food to move around the table. However, the plate obviously has wheels on it to make it move easier. (00:18:00)