It was to be a brutal day. At first light on 15 June 1944, the Navy fire support ships of the task force lying off Saipan Island increased their previous days' preparatory fires involving all calibers of weapons. At 0542, Vice Admiral Richmond Kelly Turner ordered, "Land the landing force." Around 0700, the landing ships, tank (LSTs) moved to within approximately 1,250 yards behind the line of departure. Troops in the LSTs began debarking from them in landing vehicles, tracked (LVTs). Control vessels containing Navy and Marine personnel with their radio gear took their positions displaying flags indicating which beach approaches they controlled.
Admiral Turner delayed H-hour from 0830 to 0840 to give the "boat waves" additional time to get into position. Then the first wave headed full speed toward the beaches. The Japanese waited patiently, ready to make the assault units pay a heavy price.
The first assault wave contained armored amphibian tractors (LVT[A]s) with their 75mm guns firing rapidly. They were accompanied by light gunboats firing 4.5-inch rockets, 20mm guns, and 40mm guns. The LVTs could negotiate the reef, but the rest could not and were forced to turn back until a passageway through the reef could be discovered.
Earlier, at 0600, further north, a feint landing was conducted off Tanapag harbor by part of the 2d Marines in conjunction with the 1st Battalion, 29th Marines, and the 24th Marines. The Japanese were not really fooled and did not rush reinforcements to that area, but it did tie up at least one enemy regiment.
When the LVT(A)s and troop-carrying LVTs reached the reef, it seemed to explode. In every direction and in the water beyond on the way to the beaches, great geysers of water rose with artillery and mortar shells exploding. Small-arms fire, rifles, and machine guns joined the mounting crescendo. The LVTs ground ashore...
