Gilligan’s Island may have been a simple sitcom, but the classic series was filled with amusing mistakes and behind-the-scenes details that fans can still discover today. In the season two opening credits, for example, there appear to be eight people aboard the boat instead of seven. The extra people were actually stand-ins used for distant shots, since the real cast members weren’t on the boat for those scenes.

Other bloopers are even easier to miss. In The Friendly Physician, parts of the CBS studio lot can reportedly be seen behind the supposedly isolated island set. In another episode, Natalie Schafer briefly opens her eyes while pretending to be unconscious. The pilot also contains a few production quirks, including the visible edge of the movie tank used to film the raft scenes and even a boom-mic shadow.

The show also has plenty of fascinating trivia. Alan Hale Jr. reportedly traveled by horseback, hitchhiking and plane to make his audition for the role of the Skipper. The original theme song left the Professor and Mary Ann out until season two, while the S.S. Minnow was reportedly named after FCC chairman Newton Minow. And the “submarine” in So Sorry, My Island was actually operated by a diver beneath the water.

Then there are the cast stories fans still love. Tina Louise and Dawn Wells became unforgettable as Ginger and Mary Ann, while Bob Denver’s wedding ring accidentally appeared on Gilligan’s hand despite the character being single. Sadly, Tina Louise is now the only surviving member of the original seven castaways. Which of these Gilligan’s Island facts surprised you the most?