3rd Assault Amphibian Battalion was originally activated 16 September 1942 at San Diego, California, as 3rd Amphibian Tractor (Amtrac) Battalion and assigned to the 3rd Marine Division. During December 1942 the battalion relocated from San Diego a short distance up the coast to Camp Pendleton. After training for a few months the battalion then deployed in February-March 1943 to Auckland, New Zealand in preparation for combat in the Pacific theater. During World War II, the battalion was primarily armed with Landing Vehicle Tracked (LVT), specifically the LVT-2 also known as "WATER BUFFALOS".
At the conclusion of World War II the battalion redeployed in March 1945 to Maui, territory of Hawaii and then relocated during February 1946 back to Camp Pendleton, California. It was Reactivated several months later on 1 May 1946.
3rd Amphibian Tractor Battalion was reactivated 1 April 1952 at Camp Pendleton, California, and assigned to Fleet Marine Force, Pacific. It was subsequently reassigned during October 1955 to the 1st Marine Division. Elements participated in the Cuban Missile Crisis, October–December 1962
During this period the battalion was still armed with LVTs - transitioning primarily to the LVT-5 in the late 1950s.
Description
Guam, ringed by reefs, cliffs, and heavy surf, presents a formidable challenge for an attacker. But despite the obstacles, on 21 July, the Americans landed on both sides of the Orote peninsula on the western side of Guam, planning to cut off the airfield. The 3rd Marine Division landed near Agana to the north of Orote at 08:28, and the 1st Provisional Marine Brigade landed near Agat to the south. Japanese artillery sank 20 LVTs, and inflicted heavy casualties on the Americans, especially on the 1st Provisional Marine Brigade, but by 09:00 men and tanks were ashore at both beaches. The 77th Infantry Division had a more difficult landing. Lacking amphibious vehicles, they had to wade ashore from the edge of the reef where they were dropped by their landing craft. The men stationed in the two beachheads were pinned down by heavy Japanese fire, making initial progress inland quite slow.
US Marines move inland.
By nightfall, the Americans had established beachheads about 6,600 feet (2,000 m) deep.[1] Japanese counterattacks were made throughout the first few days of the battle, mostly at night, using infiltration tactics. Several times, they penetrated the American defenses and were driven back with heavy loss of men and equipment. Lieutenant General Takeshi Takashina was killed on 28 July, and Lieutenant General Hideyoshi Obata took over the command of the defenders.
Supply was very difficult[2] for the Americans in the first days of the battle. Landing ships could not come closer than the reef, several hundred yards from the beach, and amphibious vehicles were scarce. However, the two beachheads were joined up on 25 July, and the Orote airfield and Apra harbor were captured by 30 July.
The counterattacks against the American beachheads, as well as the fierce fighting, had exhausted the Japanese. At the start of August, they were running out of food and ammunition and had only a handful of tanks left. Obata withdrew his troops from the south of Guam, planning to make a stand in the mountainous central and northern part of the island. But with resupply and reinforcement impossible because of American control of the sea and air around Guam, he could hope to do no more than delay the inevitable defeat for a few days.
Rain and thick jungle made conditions difficult for the Americans, but after an engagement at Mount Barrigada from 2-4 August, the Japanese line collapsed; the rest of the battle was a pursuit to the north. As in other battles of the Pacific War, the Japanese refused to surrender, and almost all were killed. On 10 August, after three weeks of combat, organized Japanese resistance ended, and Guam was declared secure. The next day, Obata committed ritual suicide.