The periscope in the German submarine U-571 in the movie of that name was real. It was found, still in the original crate, in a German warehouse, where it had remained since 1945. The film producers scoured Germany for submarine parts they could buy, borrow, or copy, and found the periscope on the methodically-kept inventory of the German company that owns the warehouse. One of the consultants on the film was a WWII U-boat commander [Hans-Joachim Krug]; another [Vice Admiral Patrick Hannifin] was an American naval officer who served for eight months after the war on a German submarine being evaluated by the US Navy. Hannifin had previously served on the S-33.--Stephen V Cole