JOINT BASE PEARL HARBOR-HICKAM (May 6, 2021) The Los Angeles-class fast-attack submarine USS Columbia (SSN 771) departs Pearl Harbor Naval Shipyard for sea trials, May 6, 2021. During their engineered overhaul (EOH) availability, the shipyard and crew performed essential repairs and modernization, as well as routine maintenance, to ensure the submarine operates at full technical capacity and mission capability. (U.S. Navy photo by Mass Communication Specialist 1st Class Michael B. Zingaro)