Continuity mistake: There are several shots of the island used in the series. In the opening, it appears small. In some inland shots it appears immense and mountainous, despite being described numerous times as a "tiny island somewhere in the Pacific."
Revealing mistake: Any time you see the vines used for different purposes, it's painfully obvious that they're very poorly disguised rope, such as the ones the Skipper and Professor use to rock the boat mock-up in the episode "Quick, Before It Sinks."
Plot hole: Many episodes show either visitors on the island swimming away or objects floating away on rafts (a lion, a silent film, etc) that at the end of the episode always make it safely to civilization (as heard on the radio)... yet, none of the castaways ever could swim or leave on a raft to attempt to get off the island and get rescued in the same way.
Plot hole: On many different occasions, the castaways meet a wide variety of people who say that they have been on the island for either ten or more years thinking they were the only ones on the island before the SS Minnow even arrived. With so many people who had been on the island for such an extended time, it seems kind of strange that none of them had ever met one another.
Plot hole: How could it be that every time someone or something was visiting the island during many episodes, they always made it back to civilization by the ending scene (as heard on the radio)? I can understand an actual person, but once anything else (such as a lion, a movie reel on a raft, etc.) leaves the island, it arrives perfectly by just simply slowly floating on the water with no human to guide them. Maybe the one exception could be the robot (programmed by the Professor).
Visible crew/equipment: When Gilligan puts the Skipper down, you can see the wires attached to the corners of the lounge seat.
Continuity mistake: In the opening credits, the boat used as the Minnow changes. It goes from having an upper steering deck, to flat topped and different colored, and back.
Revealing mistake: When the Professor comes over to the Robot to ask "How would you like to do us a favor?", look closely at the mesh like part of the Robot's "face", just left of the vertical black bar. You can see the Robot actor's eye blinking and looking around. When he nods, you can see the outline of the actor's head.
Revealing mistake: In the closing credits of Seasons 2 and 3, after the camera pulls back to look at the castaways on the beach of the lagoon, in the upper left corner of the shot you can see the roofline and corner of a building.
Factual error: The portable radio is an AM band only, therefore there is no need for the external telescoping FM antenna.
Continuity mistake: When the SS Minnow is shown beached on the deserted island, it's seen leaning on its left. At the ending credits, the Minnow is shown completely upright.
Continuity mistake: When they are listening to the radio report describing the lost boat, the professor goes from standing up to sitting down between shots.
Revealing mistake: After the Skipper tosses the sail into the water, look at the background. On the right side of the shot, the bottom of the backdrop is easily seen, showing this scene is filmed in a huge water tank set.
Other mistake: At the beginning of the episode when the Skipper wakes up on the boat this scene is actually from the original pilot, as you can see the 3 different actors that played the part of the professor, Ginger, and Mary Ann. (00:01:20)
Suggested correction: The original actors ARE shown, true. However their characters slightly differred in the original pilot. They were known as a high school teacher, Ginger, and Bunny.
Continuity mistake: At the beginning of the episode when everyone is listening to the radio the professor is shown standing up and in the next shot is sitting down. (00:02:50)
Continuity mistake: As they struggle with the sail, Skipper's hat is backwards. After a shot of the shark, his hat's on right as he tosses the sail.
Continuity mistake: After the shark bites off the rest of the paddle, leaving the handle, Gilligan hesitates a second, sees no paddle, and begins swatting at the shark. A moment later, in the closeup, he's paddling, hears the bite again, and pulls the handle up, showing the paddle is gone.
Continuity mistake: As the rock that triggers the trap is pulled, the vine used slides completely off it. In the wide shot, the vine is securely around the trigger rock.
Revealing mistake: When the shark takes a second bite of the raft, you can see the bite before it's taken.
Visible crew/equipment: As the camera looks at Skipper and Gilligan, after the tossing of the sail, the edge of the studio tank is visible for a few seconds in the background.
