WWII U.S. Navy Bureau of Ships Hamilton Model 21 Chronometer U.S. Navy Bureau of Ships chronometer.Ship's clock which kept cargo ships, merchantmen and warships on time on heading and gave precise readings for navigation operational readiness. A very, very accurate mechanism, the role of the Hamilton model 21 cannot be overestimated, and it has sometimes been described as "The watch that won the war" I have had this clock for a number of years, and, I had itprofessionallyevaluated forrepairs. Although the parts to repair the ship's clock are available, I feel that it would be betterappreciatedby a collector ofHamilton watches or of WW2memorabilia, so I am selling it as is, and have tried to represent the accurate condition of this historic timepiece as accurately though the use of high res pictures. Please feel free to ask any questions and I will answer them to the best of my ability, but I do not feel comfortable disassembling the clock any further than is already done for the photos. Happy offerding!