Question: In what year did the submarine that sank the Tsushima Maru open to public tours?
Sentence (from "Tsushima Maru"): Tsushima Maru (対馬丸) was a Japanese passenger/cargo ship that was sunk by the submarine USS "Bowfin" during World War II, while carrying hundreds of schoolchildren from Okinawa to Kagoshima.
Relevant evidence: Yes