Service members from the San Francisco-based U.S. Coast Guard Port Security Unit 312 don their M50 Joint Service General Purpose Mask and Mission Oriented Protective Posture gear during the Department of Defense-led Pacific Blitz 2019 exercise in Port Hueneme, California, March 6, 2019. Port Security Units conduct port operations, security, and defense in support of Combatant Commanders’ operations worldwide providing waterborne and land-based Anti-Terrorism and Force Protection for shipping and critical port facilities in conjunction with harbor defense and coastal sea control operations at the end points of United States’ Sea Lines of Communications. U.S. Coast Guard photo by Petty Officer 1st Class Matthew S. Masaschi