In 1944 the US Navy Bureau of Ordnance fitted LSM with a 5-inch/38 gun and rockets to give landing troop fire support out to 4,000 yards beyond the beach.

The high trajectory of the firepower meant it was effective against defences otherwise protected by their position on the reverse slope The LSM(R) was featured in Life Magazine of 16 April 1945 with a centerfold picture and the caption.

Two 40 mm Bofors guns were carried; a single mount at the bow and another amidships in front of the bridge.

The interim group of 12 LSM(R)s crossed to the Pacific through the Panama Canal and on to the Philippines, headed for battle against Japan in March 1945.

In a preliminary assault on 26 March 1945, they laid down a rocket barrage at dawn on Kerama Retto, a small cluster of islands off the southwestern shore of Okinawa, to allow US Army troops of the 77th Infantry Division to land and secure the islands and the harbor for protection of the hospital, supply and communication ships, and floating drydocks.

The early dawn assault surprised the Japanese; the army took control with a minimum of casualties and established a haven for damaged ships.

The northern half of the six-mile-wide invasion beach was assigned to Task Force 53, under the command of Rear Admiral Lawrence F. Reifsnider.

The southern half of the six-mile-wide invasion beach was assigned to Task Force 55, commanded by Rear Admiral John Leslie Hall, Jr.

Each station was manned around the clock by a handful of ships ranging from destroyers down to minesweepers and their task was to sound the alarm and vector fighters to intercept before they reached the fleet.

Shortly before dusk, the destroyer Aaron Ward was hit by a series of six kamikazes, suffering 45 killed or missing and 49 wounded.

Not long after sunrise the anticipated kamikazes arrived and were met by American combat air patrol.