CBs were also tasked individually to the four Amphibious Corps. The 19th CB started out with the I MAC prior to joining the 17th Marines. The 53rd CB was attached to I MAC as Naval Construction Battalion I M.A.C. When I MAC was redesignated III Amphibious Corps the battalion became an element of the 1st Provisional Marine Brigade. For Guam, III Amphibious Corps had the 2nd Special CB, 25th, and 53rd CBs. The CO 25 CB was shore party commander for the 3rd Marines on beaches Red 1 and Red 2. The 3rd Marines would award 25's shore party 17 bronze stars. V Amphibious Corps (VAC) had the 23rd Special and 62nd CBs on Iwo Jima. On Tinian the 6th Construction Brigade was attached to V Amphibious Corps.