An extremely rare watch, the very one featured in the book *Military Watches of the Sky, Land, and Sea* for officers, Naval Aviation pilots, and commanders of U-boats (Unterseeboot = submarine) in the Navy Period: 1940–1945 Production of Hanhart chronographs for the Armed Forces began in 1938 at the factory in Schwenningen am Neckar, in Baden-Württemberg (Germany) Water-resistant nickel-plated brass case with a screw-down steel caseback and fixed lugs. Bidirectional rotating metal bezel with knurled finish and unpainted red index. Black dial marked: km (Kriegsmarine = Navy), Hanhart, and featuring a red telemetric scale. The hour markers and the hour and minute hands are luminescent. The exterior of the case back is marked with: an eagle holding the Nazi swastika, and the letter 'm' (Marine = Navy); This symbol was engraved only on watches used by the Navy and indicated that they were issued to the unit; It is also marked with 097 (serial number) and “Boden Edelsthal” (stainless steel case back). The inside of the case back is unmarked. Movement: unmarked, Hanhart 40 chronograph caliber, no. 109872 The watch has never been polished and is entirely period-correct and in perfect working order. The watch’s service history is unknown, unless otherwise indicated in the description. The watches are inspected to verify that they are in proper working condition.