Four days later, "Thresher" arrived off Catmou Point, Negros Island. Under cover of darkness, the boat surfaced and delivered of stores and 40,000 rounds of ammunition to Filipino guerrillas. Receiving intelligence documents in return, "Thresher" got underway for a resumption of her patrol shortly before midnight on 9 July. She soon departed the Philippines and sailed "via" Midway Island and Pearl Harbor to the west coast for a major overhaul at the Mare Island Naval Shipyard, Vallejo, California.