JOINT BASE PEARL HARBOR-HICKAM (April 7, 2021) Cmdr. Andrew J. Kopacz, left, relieves Cmdr. Chance Litton, right, as commanding officer of the Los Angeles-class fast-attack submarine USS Chicago (SSN 721), while Capt. Mike Majewski, center, commodore, Submarine Squadron 7, presides over the ceremony. The ceremony was held on the historic submarine piers at Joint Base Pearl Harbor-Hickam. (U.S. Navy photo by Chief Mass Communication Specialist Amanda R. Gray)