Question: My sister insists an episode exists where pirates arrive on the island looking for a long-lost buried treasure. She swears she remembers the pirates kidnapping Ginger and trying to make her tell them where the treasure was. Does anyone remember this?
Answer: I'm sorry, but no such episode exists; perhaps your sister is confusing this with another show from the 70s?
Answer: This could be Season 3, Episode 17, "Court Martial," where Gilligan dreams about being an admiral whose ship gets boarded by pirates Captain Hook, Long John Silver, and Captain Kidd. (https://gilligan.fandom.com/wiki/Court-Martial)
She says that is not the episode she remembers. She said the pirates arrive on the island, don't find the treasure, kidnap Ginger, and hold her in a cave until she tells them where the treasure is. Appreciate the help though.
Answer: There was an animated version of "Gilligan's Island" on the CBS Saturday Morning lineup in the 1970s. I don't remember the episodes, but maybe that's where the episode is from.