The Maritime Expeditionary Security Detachment 231 is a naval unit of the United States Navy while Port Security Unit 312 is a unit of the Deployable Operation Group. The Navy and the Coast Guard had been working together in joint forces and goes as far back as the 18th century.
The United States Coast Guard Maritime Expeditionary Security (MESD-231) and Port Security Unit (PSU-312) is a 2.25″ round challenge coin with an antique nickel finish. It is a 3 dimensional coin with painted details on both sides with rope edging and no epoxy. This was created for the said unit based in San Francisco, California and is exclusively minted by U.S. Challenge Coins and available in limited edition.
The Maritime Expeditionary Security Force (MESF) is a unit of the United States Navy and its main mission is to enforce protection through fleet support operating throughout the world. Anti – Terrorism and Force Protection operations include harbour and homeland defense, coastal surveillance and special missions. Specialized units work together with Maritime Expeditionary Security Force Squadron providing intelligence and communications. They are deployed around the world to detect, deter and defend an area, unit and High Value Asset.
Port Security Units are one of the units operating under the Deployable Operations Group. They are tasked to maintain force protection operations and can be deployed within 96 hours and establish operations in 24 hours. They conduct nationwide port security and provide waterside protection. They can operate in U.S territorial waters under the Coast Guard or Maritime Defense Zone (MDZ) command or in foreign waters as part of the MESF in cooperation with the Navy Expeditionary Combat Command.
Port Security Units work in support of the homeland security operations around the country and were deployed to the Persian Gulf in support of Operation Desert Storm in 1990. They were also deployed in Haiti in 1994 in support of Operation Uphold Democracy and most recently in response to the 2010 devastating earthquakes in Haiti. PSU 309 was part of the force that was deployed in Middle East and was task to provide vital force protection for the Navy assets during the USS Cole attack in Port Alden, Yemen.
The Coast Guard Port Security program started with the passage of the Espionage Act of 1917 and because of the Black Tom explosion wherein the Germans sabotage the American ammunition supplies to prevent the Allies from using the materiel in World War I.
This act made the Coast Guard’s Captain of the Port responsible for the security of the port areas. In World War I, port security operations were directed by active duty personnel. However, interest in port security declined until burning ships were seen from U.S. shores as it entered World War II. This caused the creation of Temporary Reserve made up of armed volunteers under the command of the Captain of the Port and over 125,000 citizens served as Temporary Reserves. Currently, each of the Port Security Units contains six fast and Maneuverable Transportable Port Security Boats and Boston Whalers.
The United States Navy and the United States Coast Guard had a long history working together and you can see most of the few challenge coins available under the Coast Guard niche having reference to the different navy units.