LONG BEACH, Calif. (Dec 5, 2023) Chief Personnel Specialist Zinzy Spencer rehearses procedures for operating an M2A1 .50-caliber machine gun, under instruction from Engineering 1st Class Enrique Peraza, aboard a 34-foot patrol boat assigned to Maritime Expeditionary Security Squadron (MSRON) 11 during continuum of force drills as part of Maritime Expeditionary Security Force (MESF) Boat University (BU). MESF BU is designed to train and qualify Sailors to sustain mobilization readiness. As a subcomponent of Navy Expeditionary Combat Command, the MESF is a core Navy capability that provides port and harbor security, high value asset security, and maritime security in the coastal and inland waterways. (U.S. Navy photo by Chief Boatswain�s Mate Nelson Doromal Jr.)