GUAM, MARIANAS 53rd NCB - SEABEES Early in June, 1944, the 53rd was attached to the First Provisional Marine Brigade, for the assault operation on Guam, in the Marianas group. Leaving a rear echelon of two officers and 79 men, the remainder of the Battalion embarked on two ships, on june 6, 1944. En-route to the island, plans for the Battalion's part in the invasion were carefully laid and gone over almost daily. Two special beach parties, composed of volunteers, were assigned to assist in the landing operations and unloading of supplies on D-Day, June 21. The remainder of the Battalion moved ashore on D-Plus-3, to set up their camp near Agat Village. Concurrently with the construction of quarters for themselves, the Bees were almost continuously occupied with the task of clearing debris from existing roads, clearing jungle, and constructing new roads to facilitate movement of supplies to the Marines at the front.LT. Commander Thompson's official report of the Battalion's activities on the Guam invasion is Quoted: At Guam, Marianas, two beach parties were assigned from the 53rd NCB. One officer and 17 enlisted men, euipped with several tractors, landed on D-Day (H-Plus-5 minutes), July 21, 1944, with special mission to assist unloading a Marine Battery of Sherman Tanks from LCM's and LCT's at the edge of the reef at Agat Beach. This task was finished within an hour under heavy enemy mortar and machine gun fire. Three of the Sherman Tanks dropped into bomb craters on their way in from the reef to shore and were submerged. This party volunteered to rescue these Tanks and succeeded in getting two of the Tanks safely to the beach in two hours, under heavy fire. A second beach party of five enlisted men was assigned the task of operating a North West Crane, mounted on a pontoon barge and anchored off the reef of Agat Beach, to unload gasoline and ammunition from LCT's to LVT's in support of assault troops. The barge was under heavy mortar fire for the first four days.. The remainder of the Battalion moved ashore on D-Plus-3 and established, maintained, and constructed roads and bridges in support of the assault troops. The Battalion's beach camp was under enemy artillery fire for four hours on D-Plus-3. The 53rd NCB maintained the only Seabee Demolition Squad on the island, consisting of a Chief Petty Officer and 13 enlisted men.. This squad cleared all beaches, roads and areas ahead of construction troops over a nine months period. While the 53rd NCB was attached to the First Provisional Brigade, during the initial landing on Guam, they were detached from the Marines on July 27, 1944, and assigned duty under the Fifth Naval Construction Brigade.