Gilligan's Island would do a crossover episode with Scooby Doo, Where Are You? the cartoon mystery series. This may be an in-joke, as the character of Shaggy was inspired by the character of Maynard Krebbs on Dobie Gillis, who was played by Bob Denver.
Professor Roy Hinkley:
I'll get Mr. Howell and we'll reconnoiter.
Skipper Jonas Grumby: All right, we'll get Mr. Howell and we'll reconnoiter. Come on.
Gilligan: Okay, but I think we ought to scout around a bit first.
In the first season, the Minnow shown in the opening credits is beached, leaning on it's left (port) side. In the closing credits, the Minnow is beached perfectly upright.
During the first season's opening credits, for some reason neither The Professor, Russell Johnson nor Mary Ann Dawn Wells received an on screen billing, nor were they referred to in the theme song. They were just referred to as "... and the rest." For seasons two and three they were added at the request of Bob Denver, who played "Gilligan" and thought it was stupid to leave out the two actors just to shorten the introductory song by a few notes.
There are two different versions of the homing pigeon episode. Version 1 has a scene of Gilligan and Skipper sneaking into the professor's hut and feeding the pigeon a pie, followed by Ginger and Mary Ann giving it milk; this version airs on TBS. Version 2: Gilligan and Skipper are talking in the hut and the dialogue between Ginger and Mary Ann is shortened. This version airs on TV Land.