SEAL BEACH, Calif. (June 13, 2021) Chief of Navy Reserve Vice Adm. John B. Mustin walks through ceremonial side boys during his visit to Maritime Expeditionary Security Squadron (MSRON) 11 at Naval Weapons Station Seal Beach, June 13, 2021. Maritime Expeditionary Security Force (MESF) operates in harbors, rivers, bays, across the littorals and ashore. The primary mission of MESF is to conduct maritime security operations across all phases of military operations by defending high value assets, critical maritime infrastructure, ports, and harbors both inland and on coastal waterways. (U.S. Navy photo by Chief Boatswain�s Mate Nelson Doromal Jr.)