Naval Overseas Transportation Service

Military Sealift Command
The logo of Military Sealift Command shows an outline of a grey ship on a stylized ocean displaying blue and gold stripes.
Active	9 July 1949 – present
Country	United States of America
Branch	United States Navy
Commanders
Current commander	RADM Dee L. Mewbourne, USN (25 August 2016 – present)

The Military Sealift Command (MSC) is a United States Navy organization that controls the replenishment and military transport ships of the Navy. The United States Military Sealift Command has the responsibility for providing sealift and ocean transportation for all US military services as well as for other government agencies. It first came into existence on 9 July 1949 when the Military Sea Transportation Service (MSTS) became solely responsible for the Department of Defense's ocean transport needs. The MSTS was renamed the Military Sealift Command in 1970.

Military Sealift Command ships are made up of a core fleet of ships owned by the United States Navy and others under long-term-charter augmented by short-term or voyage-chartered ships. The Navy-owned ships carry blue and gold stack colors, are in service with the prefix USNS (United States Naval Ship), rather than in commission (with a USS prefix), have hull numbers as an equivalent commissioned ship would have with the prefix T- and are primarily civilian manned by either civil service mariners or contract crews (see United States Merchant Marine) as is the case of the special mission ships. Some ships may have Navy or Marine Corps personnel on board to carry out communication and special mission functions, or for force protection. Ships on charter or equivalent, retain commercial colors and bear the standard merchant prefix MV, SS, or GTS, without hull numbers.

Five programs comprise Military Sealift Command: Combat Logistics Force, Special Mission, Prepositioning, Service Support, and Sealift. The Sealift program provides the bulk of the MSC's supply-carrying operation and operates tankers for fuel transport and dry-cargo ships that transport equipment, vehicles, helicopters, ammunition, and supplies. The Combat Logistics Force’s role is to directly replenish ships that are underway at sea, enabling them to deploy for long periods of time without having to come to port. The Special Mission program operates vessels for unique military and federal government tasks, such as submarine support and missile flight data collection and tracking. The Prepositioning program sustains the US military's forward presence strategy by deploying supply ships in key areas prior to actual need.