190920-N-KB401-0156 PEARL HARBOR (Sept. 20, 2019) Cmdr. Douglas Pratt, from Nashua, New Hampshire, commanding officer of the Los Angeles-class fast-attack submarine USS Tucson (SSN 770), addresses the crowd during a change of command ceremony for Tucson on the submarine piers, Sept. 20, 2019. Pratt relieved Cmdr. Chad Hardt, from Aiken, South Carolina, as Tucson’s commanding officer. (U.S. Navy photo by Mass Communication Specialist 1st Class Michael B. Zingaro/Released)