Naval Submarine School celebrated the retirement of Chief Warrant Officer 3 Mark Cooper during a ceremony onboard Naval Submarine Base New London, Groton, CT, on April 30, 2021. Serving as SUBSCOL’s Pressurized Submarine Escape Trainer diving officer, Cooper retired after over thirty years of service in the U.S. Navy. He was a consummate leader, and a critical figure in maintaining quality of instruction within SUBSCOL’s high-risk training department. (U.S. Navy photo by Charles E. Spirtos/Released)