Japanese naval personnel occupied Pratas Island during World War II. The Japanese Navy used the island as a weather station and listening post. On May 29, 1945, at 10:22 AM, a landing party consisting of Australian commandos and US naval personnel from the submarine raised the US flag, declared the island a United States territory, and named it Bluegill Island. The landing party destroyed a radio tower, weather station, fuel and ammunition dumps, and several buildings. They encountered no resistance because the Japanese had left the island prior to the arrival of "Bluegill".