200125-N-XL095-1018 GUAM (Jan. 25, 2020) Builder 2nd Class Brock Farmer, assigned to Construction Diving Detachment Charlie (CDD/C) from Underwater Construction Team TWO uses calipers to measure the thickness of a chain. The measurement correlates with the deterioration rate of the chain and indicates when it should be replaced. (U.S. Navy photo by Builder 2nd Class Cedric Ellison/Released)