the 6th Marine Division was not at Tarawa. The 6th Marine Division was at Okinawi. They were made up of the 4th Marine Regiment, the 4 Marine Raider Battalions, the 22nd Marines, The 29th Marines, the 15th Marine Regiment Artillery, and the 6th Division special troops...theTank, Engeneer,Motor Transport, Medical, Service, and Headquarters. These were all battle tested Marines from previous battles. At Guam they were formed into The First Provisional Marine Brigade. At Guadalcanal the were redesignated The 6th Marine Division. The Only Division formed overseas and disbanded over seas