A fighter base to provide repair and overhaul facilities for carrier aircraft was constructed by the 78th Naval Construction Battalion on Ponam Island. As half of the work area was swamp, coral was blasted and dredged from the ocean bed and used as landfill. Another facility for carrier aircraft was built on Pityilu by the 71st Naval Construction Battalion in May and June 1944, along with accommodation for 2,500 men. The eastern end of Pityilu was cleared and a fleet recreation centre was built that could accommodate up to 10,000 at a time.