Continuity mistake: In this episode, the damage to the boat is different than seen in "Two on a Raft." Also, there was a vessel number on the bow of the boat that is absent in this episode.
Other mistake: Where Gilligan is yelling to everyone "Don't get on the minnow, the glue won't hold!" you can see a pack of Chesterfield cigarettes sticking out of his left front pants pocket.
Revealing mistake: While they are at the front or side of the damaged boat, you can see that the dark windows above them are obviously painted on, rather poorly in some spots, and not real windows.
Chosen answer: It looks like a mistake to me I see it when the Professor is put into a trance, but it is not there later.
Bowling255 ★