This unit was part of the Mobile Riverine Force TF-117. The purpose of the Mobile Riverine Force was to support an Army infantry brigade and an Army artillery battalion using modified landing craft, support ships, and specially designed assault boats. The strike unit would be a self-contained amphibious assault force with all support elements except initially aircraft, which were added later. Because the Marines were heavily engaged in I Corps, a brigade from the Army’s 9th Infantry Division was chosen as the infantry component of the MRF in IVCorps. The Navy’s component of TF-117 was a wide variety of ships and boats. The first unit, River Assault Flotilla One (RivFlotONE) was composed of River Assault Squadron 9 (RAS 9) and RAS 11. Each of the River Assault Squadrons was composed of two River Assault Divisions: RAS 9 had Divisions 91 and 92; RAS 11 had Divisions 111 and 112. Very nice example of this scarce patch that measures approximately 11cm x 10cm.