The Military Sealift Command traces its origins to the Military Sea Transportation Service (MSTS), which was formed in 1949 to consolidate the military maritime transportation efforts of four distinct U.S departments: the U.S. Maritime Commission’s War Shipping Administration, Army Transportation Service, Naval Overseas Transportation Service, and Fleet Support Services. The MSTS was redesignated the Military Sealift Command with a goal of transitioning from Navy to Civilian Mariners (CIVMAR) for service on fleet support ships, thus freeing up highly trained Navy personnel to serve on vessels in the Navy’s fleet.
The rank insignia worn by officers serving aboard Military Sealift Command ships is clearly derived directly from the Navy’s insignia system, but different titles are employed based upon seniority and job classification. This insignia, which invokes images of the “butterbar” worn by Ensigns in the Navy and Coast Guard, is worn by Third Officers in the Deck Department and by Third Assistant Engineers in the Engineer Department.