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.
Continuity mistake: After the shark bites Gilligan's paddle and he holds it up, the amount of wood between the handle's connection and the bite differs from shot to shot.
Revealing mistake: When the shark is attacking Gilligan's oar the second time, it stops completely for a couple of seconds.
Revealing mistake: As the shark goes by the floating bottle and towards the camera, the underwater rail the prop shark rides on is obvious.