This episode actually shows a map of the island in large.
Even though he is portraying an Englishman in this episode, John McGiver in real life was born in New York City.
Don B. Ray did a substantial amount of new score for this episode and did not receive credit. It was recorded September 1, 1966 CBS Studio Center along with the episode score "Ring Around Gilligan" (Gerald Fried). Conducted by Morton Stevens.
Season 3 switched the location of the professor and Mary Anns photos in the opening credits. BH