The delay in the advance of Japanese forces also allowed the Marine Corps to land on Funafuti on 2 October 1942, with a Naval Construction Battalion (Seabees) building airfields on three of the atolls of Tuvalu from which USAAF B-24 Liberator bombers of the Seventh Air Force operated. The atolls of Tuvalu acted as a staging post during the preparation for the Battle of Tarawa and the Battle of Makin that commenced on 20 November 1943, which was the implementation of Operation Galvanic.