The Maritime Expeditionary Security Force (MESF) is a unit of the United States Navy within the organizational structure of the Navy Expeditionary Combat Command. The MESF stems from the Naval Coastal Warfare community which is transitioning to the MESF, Naval units affected range from mobile inshore undersea warfare units, inshore boat units, naval coastal warfare squadrons.[1] The MESF's primary mission is force protection conducted through fleet support with operations around the world. Anti-terrorism and force protection missions include harbor and homeland defense, coastal surveillance, and special missions. Specialized units work together with MESF squadron staffs providing intelligence and communications. MESF units deploy worldwide to detect, deter, and defend an area, unit, or high value asset. Recent locations include the United States, Panama, Korea, Saudi Arabia, Kuwait, Iraq, Afghanistan, Bahrain, United Arab Emirates, and Egypt.
Ratings range from Master-at-Arms to Boatswain's Mates, to Information Technology Specialists to Hospital Corpsmen. Preliminary units received training in small arms, crew-served weapons,and close quarters battle at places such as the Blackwater Training Center in Myock, North Carolina. Expeditionary Designated Marksman training conducted by the "in house" Special Missions Training Division of MESG-2 turns out shooters capable of sub MOA (minute of angle) accuracy.
Two Maritime Expeditionary Security Groups in San Diego, California and Portsmouth, Virginia provide centralized planning, control, training, coordination, equipping, and integration of coastal warfare assets trained to operate in high density, multi-threat environments. Units conduct force protection of strategic shipping and naval vessels operating in the inshore and coastal assets, anchorages and harbors, from bare beach to sophisticated port facilities." Members of this community are highly encouraged to earn their Expeditionary Warfare Specialist Designation.