Mobile Diving and Salvage Unit (MDSU) TWO patch. 4″ size, heat seal (iron-on) back.
Mobile Diving and Salvage Unit (MDSU) TWO is an expeditionary mobile unit homeported at Joint Expeditionary Base (JEB) Little Creek-Ft. Story that deploys in support of diving and salvage operations and fleet exercises in NORTHCOM, SOUTHCOM, EUCOM, AFRICOM  and CENTCOM AOR’s.  It’s primary mission is to direct highly mobile, fully trained and equipped Mobile Diving and Salvage Companies to perform combat harbor clearance/search and expeditionary salvage operations including diving, salvage, repair, assistance, and demolition in ports or harbors and at sea aboard United States Navy (USN), Military Sealift Command (MSC) or commercial vessels of opportunity in wartime or peacetime.
MDSU TWO was originally established as Harbor Clearance Unit (HCU) TWO at Naval Amphibious Base (NAB) Little Creek on 01 October 1966.  Patterned after World War II mobile salvage units, HCU TWO consolidated the diving resources of the Atlantic Fleet in order to clear harbors and waterways during the Vietnam War.  Along with her sister command, (HCU ONE) HCU TWO salvaged hundreds of small craft, barges, and downed aircraft; refloated many stranded U.S. Military and merchant vessels; cleared obstructed piers, shipping channels, and bridges; and performed numerous underwater repairs to ships operating in the combat zone.
The command offically became Mobile Diving and Salvage Unit TWO in Febuary 1982, reflecting the new focus on salvage operations and specialized diving missions.  Over the years, MDSU TWO earned the title of “Experts in Salvage” through participation in numerous salvage/recovery operations, harbor clearance, humanitarian operations and battle damage assessment and repair.  The heavy salvage capabilities of MDSU TWO have been demonstrated during such salvage operations as: TWA-800, Swiss Air Flight 111, Space Shuttles Challenger and Columbia, and the salvage of USS MONITOR’s steam engine, turrent, eleven-inch Dahlgren guns and crew remains.  MDSU TWO has been involved in quick response battle damage asessments and repair on such vessels as: USS La Moure County (LST 1194) and USS COLE (DDG 67).  They have also been involved in many humanitatian missions such as the Minneapolis Minnesota Bridge Collapse, aftermath of Hurricane Katrina and 2010 Haiti Earthquake.
Responding to the CNO’s vision to align forces, MDSU TWO took full opportunity to train in expeditionary skills as part of Navy Expeditionary Combat Command deploying in support of Operations ENDURING FREEDOM and IRAQI FREEDOM / NEW DAWN, Anti-Terrorism Force Protection, and Theater Security Engagements with friendly nation Naval Diving forces from NORTHCOM, SOUTHCOM, EUCOM, AFRICOM and CENTCOM AOR’s.
MDSU TWO continues to support current and future fleet requirements providing six Mobile Diving and Salvage Companies (MDS Co) with fly-away diving systems and recompression chambers, an Area Search Platoon (AS Plt) with Unmanned Underwater Vehicles (UUV) and Side Scan Sonar capabilites and a deployable Command and Control element.