[6] Some ships may have Navy or Marine Corps personnel on board to carry out communication and special mission functions, or for force protection.

[7] Ships on charter or equivalent, retain commercial colors and bear the standard merchant prefix MV, SS, or GTS, without hull numbers.

[15] In 2015, the Military Sealift Command underwent further restructuring with the relocation from the former headquarters at Washington Navy Yard to Naval Station Norfolk.

These MSC ships are painted haze gray and can be easily identified by the blue and gold horizontal bands around the top of their central smokestack.

[19] The MSC Prepositioning Program supports the US Army, Navy, Air Force and Marine Corps and the Defense Logistics Agency.

Prepositioning ships remain at sea, ready to deploy on short-notice the vital equipment, fuel and supplies to initially support military forces in the event of a contingency.

This consists of the class of ships formerly known as the Joint High Speed Vessel (JHSV) program but was changed to (EPF) in September 2015.

The EPF will reach speeds of 35–45 knots (65–83 km/h; 40–52 mph) and will allow for the rapid transit and deployment of conventional or special forces as well as equipment and supplies.

MSFSC was formed from the following MSC elements: Portions of Sealift Logistics Command Atlantic and the former Naval Fleet Auxiliary Force East; Portions of Sealift Logistics Command Pacific; Naval Fleet Auxiliary Force West (except those positions remaining in SSU San Diego); and The Afloat Personnel Management Center.

MSFSC has ship support units, or SSUs, in Naples, Bahrain, Singapore, Guam, Yokohama and San Diego.

MSFSC was disestablished following restructuring when Military Sealift Command relocated to Naval Station Norfolk from the Washington Navy Yard.

Following the Mexican–American War, Brigadier General Thomas S. Jesup, Quartermaster of the Army, recommended that the Navy be given responsibility for all water transportation requirements for the military.

The command assumed responsibility for providing sealift and ocean transportation for all military services as well as for other government agencies.

In addition to transporting troops and combat equipment to and from Korea, command ships supplied US bases and Distant Early Warning line construction sites and supported US nation building efforts from Europe and Africa, to the Far East.

In 1971 Chief of Naval Operations Admiral Elmo Zumwalt proposed the use of MSC ships for direct support of the fleet at sea.

To determine the feasibility of this concept, Admiral Zumwalt directed the formation of a special study group to recommend how the navy could better utilize the MSC fleet to save both manpower and money.

The study concluded that significant savings could be achieved if civilian mariners could be substituted for uniformed navy sailors in fleet support ships.

Extensive trials were conducted using the civilian crewed merchant tanker SS Erna Elizabeth equipped with both alongside and astern fueling gear to test the feasibility of augmenting (not replacing) the service force with ships of the U.S.

After its transfer, the ship underwent a thorough overhaul that included refurbishment of equipment, gear, and refueling rigs, modification of crew quarters, and the removal of armaments.

The lack of sufficient numbers of AOEs or AORs precluded the deployment of these types in support of any of the surface warfare groups, which were generally composed of destroyers and frigates.

By the time the USNS Henry J. Kaiser (T-AO-187) entered service on 19 December 1986, the Navy had transferred the five Second World War vintage tankers of the Mispillion class and the six 1950s-built Neosho-class fleet oilers to the Military Sealift Command.

At the high point of the war, more than 230 government-owned and chartered ships delivered the largest part of the international arsenal that defeated Saddam Hussein in Iraq.

MSC was also involved in the 2003 invasion of Iraq, delivering 61,000,000 square feet (5.7 km2) of cargo and 1,100,000,000 US gallons (4,200,000 m3) of fuel by the end of the first year.