 Their advance took them straight into anti-personnel mines and booby traps, which duly exploded, and then into the fields of fire of the Americans' automatic weapons, including several .30 water-cooled Browning machineguns, but the advance continued.The guns of the 211th Coast Artillery (AA) Battalion and 99th Field Artillery Battalion fired through the night, attempting to break up the Japanese attack from Porlaka.Shortly after midnight, Japanese barges attempted to cross Hyane harbour but were engaged by anti-aircraft guns and did not reach the American positions.