SAN DIEGO (March 10, 2021) 2nd Battalion 5th Marines from Camp Pendleton, participate in crew served weapons training provided by Maritime Expeditionary Security Group (MESG) 1 Training Evaluation Unit during an Embarked Security Team Training course. The Maritime Expeditionary Security Force 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 Gunner's Mate 1st Class Christopher Olson)