75 Years Ago: U.S. Coast Guard Operations at Okinawa

LSTs at Okinawa (USCG)

Published May 4, 2020 1:56 PM by U.S. Coast Guard News

[By BM1 William A. Bleyer, U.S. Coast Guard]

In late March 1945, nearly 1,300 ships of the Allied forces of America, Great Britain, Australia, New Zealand, and Canada assembled to support the largest amphibious operation of the Pacific War–the invasion of Okinawa and Ryukyu Islands.

Map showing the Ryukyu Islands, including Okinawa and nearby Kerama Retto. (U.S. Coast Guard)

Okinawa is a large island, sixty miles long and nearly ten wide. It lies only 360 miles from Japan and was part of the Japanese colonial empire. Japanese leaders were determined to hold the island, both out of national pride and as a key to their East China Sea defensive perimeter. Although its native inhabitants did not consider themselves Japanese, to Japan’s leaders Okinawa was home territory. Trying to maintain their “island hopping” momentum, Allied planners wanted to get closer to the Home Islands by landing on the “back porch” of Japan at Okinawa.

Allied military strategists codenamed the plan to invade Okinawa Operation “Iceberg.” Attached to the invasion armada was the largest fleet of Coast Guard ships to participate in a World War II naval operation. In all, the Coast Guard operated seven transports, 29 LSTs (Landing Ship, Tank), 12 LCIs (Landing Craft, Infantry), high-endurance cutters Bibb and Taney, buoy tender Woodbine, and submarine chaser PC-469. Many of these vessels and their Coast Guard crews were veterans of amphibious campaigns in the Pacific, Atlantic, and Mediterranean theaters. 

LSTs landing equipment and supplies on the beaches of Okinawa. In the distance can be seen dozens of vessels of the invasion fleet. (U.S. Coast Guard)

For Okinawa’s defense, the Japanese Imperial Army and Imperial Navy assembled hundreds of aircraft, small boats, manned torpedoes and kamikaze (meaning “Divine Wind”) suicide aircraft. The island’s Japanese defenders numbered 120,000 troops. The Allies committed over 500,000 men, including three Marine Corps divisions and four Army infantry divisions with an Army infantry division held in reserve in New Caledonia.

Six days before the main landings, an Allied task force invaded the Kerama Retto islands about 20 miles west of Okinawa. The task force included the cutter Bibb, six Coast Guard-manned LSTs and troops of the U.S. Army’s 77th Infantry Division. Coast Guard-manned LST-829 had the honor of landing the first infantrymen to invade the Japanese-held islands. After capturing Kerama Retto, these troops set-up an advanced fueling depot, repair base and air field to support the invasion forces. 

Allied military planners designated April 1st as “L-Day,” the landing day in which the Okinawa invasion would commence. As in previous campaigns, the Allies curtailed local enemy air and sea operations before initiating the invasion. In addition, the Navy brought up two bombardment fleets and, for over a week before the landings, carrier planes, B-29 heavy bombers and warships softened up enemy positions. 

Burned out mid-section of LST-884 after the deadly kamikaze attack. (U.S. Coast Guard)

In the early morning of Easter Sunday, thousands of ships of the armada arrived off Okinawa. At 8:30 a.m., fire support ships began laying down an intense onshore barrage. Over 500 planes from American aircraft carriers swarmed over the landing areas to knock out enemy positions. Allied strategists had planned the initial assault for the western and southern sides of the island because two enemy airfields lay nearby. During the initial landings, Allied forces put ashore four divisions abreast over an eight-mile front of beaches.          

Coast Guard-manned LSTs performed with their usual efficiency, both during the initial landings and with vital logistical support in the following weeks. These awkward vessels, also known as “Large, Slow Targets,” arrived after about a week at sea overloaded with troops and supplies. They lay close to the beaches and regularly made smoke screens for invasion vessels while their crews dashed to general quarters during countless air raids.

Photo of Coast Guard-manned LST-884 unloading troops and supplies before its catastrophic kamikaze attack at Okinawa. (U.S. Coast Guard)

On L-Day, LST-884 approached with the invasion fleet, steaming at three knots toward the beaches. By 6:00 a.m., under a moonlit sky, general quarters were sounded for the Coast Guard crew and the 300 Marines. Less than 30 minutes later, lookouts spotted three Japanese planes flying about 250 feet above the water bearing down on the invasion fleet. LST-884’s port guns and guns from other ships opened fire. The barrage brought down two of the aircraft. The third burst into flames and crashed into the port side of the LST. The aircraft passed through the shipfitter’s shop and continued into the tank deck where it exploded with a tremendous roar.

Repair parties worked feverishly to put out the fire, but the kamikaze had crashed into stowed mortar ammunition. The intense fire and exploding ammunition made it impossible for the men to fight the fire and heavy smoke began to fill the 884. As the fire burned out of control, the danger of flames reaching the fuel tanks increased. At 5:55 a.m., commanding officer, LT Charles Pearson, ordered the ship abandoned and the surviving men transferred to nearby vessels. After most of the ammunition had exploded, LT Pearson returned to the LST with volunteers and put out the fires. They saved the ship, but 19 Marines and one Coast Guardsman had perished in the inferno.

Troop transport Joseph T. Dickman at anchor in the Pacific unloading supplies to waring LCVPs under a cloudy sky. (U.S. Navy)

Despite the kamikaze attacks, the landings proceeded better than perhaps any other in the Pacific invasion. Coast Guard-manned troop transports entered the fray on the first day. The transport Joseph T. Dickman arrived at the transport area at 5:40 a.m. on L-Day. The Dickman had on board a total of 1,368 troops, 99 vehicles and over 83,000 cubic feet of cargo. Combat loading for an amphibious assault has been compared to a chess game that cannot be won, and the mixed cargo of troops and supplies caused delays in unloading. The Dickman continued to unload as late as April 9th, L-Day plus seven. On March 28th, the Cambria had sailed from Ulithi Atoll arriving off Okinawa just before 5:00 a.m. on April 1st. The transport served as a flagship for one of the transport groups and spent three days unloading troops and cargo. On April 3rd, the Cambria sent ashore a beach party of three officers and 43 men to speed supplies to the front lines. 

Coast Guard beachmasters and their men waged war against an unseen enemy of coral reefs. Beach parties blasted numerous coral heads allowing landing craft access to the landing zones. Due to the need for supplies, beachmasters unloaded as many landing craft as possible for six hours around high tide, piled the supplies on the beach and then moved the material inland at low tide. Unfortunately, this kept the transports at anchor for longer periods endangering the vessels from attacks by the kamikazes, suicide boats and torpedo craft.

Kamikaze photographed just before crashing into an Allied naval vessel. (U.S. Navy)

The Allies applied lessons learned from earlier amphibious assaults. Several hours after the troop transports arrived, control craft deployed for the beaches to establish a line of departure. Each of the control craft displayed a unique colored banner corresponding with the color designating each beach. A guide boat then directed each wave of craft from the line of departure to the beach. These boats also flew a pennant that corresponded to the beach’s color. Additionally, the landing craft on the initial waves had the color of the beach painted on their topsides. As the first wave reached the shore, the landing party erected a colored banner to guide landing craft arriving later. This coloring system simplified movement of boats from the line of departure to the beach and helped beachmasters recognize the boats and direct them to the proper landing areas.

With the exception of a few air attacks, light artillery and mortar fire, the Japanese had not contested the beach landings. On L-Day, Allied naval forces landed 50,000 troops. Within two days, these troops had fought to the east side of the island cutting Japanese forces in two. Resistance in the northern portion of the island fell quickly, but Japanese resistance grew tenacious in the southern end.

Troops coming ashore from an LCVP from the Dickman on the left. (U.S. Navy)

On April 6th, the Japanese began a counterattack against the invasion fleet. To attack Allied ships, the Japanese used manned torpedoes and small speedboats loaded with explosives. The Japanese hid over 250 of these suicide boats around the island, however, Allied forces captured coastal areas before most were deployed. Coast Guard submarine chaser PC-469 encountered three suicide boats sinking two in a close-quarters firefight and drove off a third. PC-469 would also shoot down two enemy aircraft later in the battle.

Within flying range of the Japanese Home Islands, the Allied fleet was subjected to frequent air attacks, many by kamikazes. These suicide attacks were deadly and included conventional aircraft and rocket-powered flying bombs called Ohkas launched from bomber motherships. Allied fighter aircraft engaged the Japanese attackers while ship-mounted anti-aircraft guns of all calibers frantically fired skyward at the enemy. The kamikazes focused on large ships like aircraft carriers, but attacked any target of opportunity. Coast Guard 327-foot cutters Bibb and Taney, veterans of the Battle of the Atlantic, served as amphibious command ships and found themselves in the thick of the action. Bibb survived 55 air raids and shot down one aircraft. Taney, which began the war on December 7, 1941, firing at Japanese planes attacking Pearl Harbor, set general quarters 119 times, shot down at least four enemy aircraft, and even took fire from a Japanese shore battery.

Coast Guard Cutter Bibb configured as an amphibious command ship with added radio antenna and anti-aircraft guns. (U.S. Coast Guard)

Growing desperate to stop the invasion, the Japanese even sortied Yamato, the world’s largest battleship, on a one-way suicide mission to attack the invasion fleet. However, American carrier aircraft sank the enemy behemoth before it reached Okinawa. During the campaign, suicide attacks sank six Allied ships and damaged another 120 vessels.

Okinawa was the last major invasion of the war. Despite their numerical superiority, the Allies took three months to secure the island. The battle claimed over 13,000 American lives and wounded 36,000 more. The Japanese lost 120,000 men, including troops, pilots and naval personnel. Frequently caught in the crossfire or conscripted to fight by the Japanese, nearly half the Okinawan civilian population died in the battle. 

Coast Guardsmen visit Okinawa’s temporary military cemetery to pay respects to a fallen shipmate. (U.S. Coast Guard)

The Okinawa Campaign was one of countless Coast Guard supported operations of World War II. Coast Guard-manned ships would participate in other minor amphibious assaults, and support Allied forces as they occupied Japan after its August 1945 surrender. In 1946, in the ceremony returning the Coast Guard to the Treasury Department, Navy Secretary James Forrestal stated that the Coast Guard had, “Earned the highest respect and deepest appreciation of the Navy and Marine Corps. Its performance of duty has been without exception in keeping with the highest traditions of the naval service.”

Throughout the war, the men and women of the United States Coast Guard demonstrated the Service’s combat readiness and lived up to its motto of Semper Paratus.

This article appears courtesy of Coast Guard Compass and may be found in its original form here

The opinions expressed herein are the author's and not necessarily those of The Maritime Executive.