Seventy-Five Years Ago: D Minus Two at Iwo Jima

On the morning of February 17, 1945, Private Jinkichi Shioiri of the 309th Independent Infantry Battalion, stationed high on the slope of Mount Suribachi on a small island situated about 670 miles south of Tokyo, recorded in his journal:

"Twenty odd large and small landing craft approached the south boat basin, as if to land.”

The island’s commander, Lieutenant General Tadamichi Kuribayshi, instructed his troops, “All shout Banzai for the Emperor! I have the utmost confidence that you will all do your best. I pray for a historic fight!”       

Among the Marine Corps' legendary locales, Iwo Jima ranks right up with, and arguably surpasses, the Halls of Montezuma and the Shores of Tripoli combined. Much of this actually stems from the fact that there was a sizable military and civilian press corps presence with the Marines on the island after they began landing on February 19, D-Day, culminating in the iconic image by Associated Press photographer Joe Rosenthal, which cemented the hard-won victory in the public imagination as being almost exclusively the work of the Marine Corps.

Although its has been long recognized that Joe Rosenthal's iconic image taken atop Mount Suribachi (seen here reproduced on a postage stamp issued only a few months after the battle) during the invasion of Iwo Jima shows Marines and Sailors, the Navy UDT "frogmen" were literally out of the picture in terms of public perceptions of the battle. (Gwillhickers via Wikimedia Commons) 

Because of Iwo Jima's strong association with the Corps, one could be forgiven for thinking that the only non-Marines to take part in the battle served in support roles: Corpsmen who tended to the Marines’ wounds, the Navy and Coast Guard coxswains who brought them to the beach, and the Gunner's Mates and Naval Aviators who pounded the pillboxes from the sea and sky in the months leading up to D-Day, particularly the three days of almost ceaseless naval bombardment that began on February 16, 1945, leading up to the Marine landings on February 19. Yet few remember the unconventional Navy warriors who were setting the stage for the invasion, facing the fiercest fire the Emperor Showa’s Subjects could throw at them while paddling little rubber boats and wearing little more than swim trunks, flippers and masks, slathered with grease to protect them from the 59-degree water, and and carrying only knives for protection. The legendary war reporter Ernie Pyle called these men "half fish and half nuts" and thought their dangerous exploits would be great material for a story, but Pyle (who was killed reporting on the Okinawa invasion a couple of months after the Iwo Jima operation) and other reporters like him were prohibited from reporting on the Navy's Underwater Demolition Teams. 

Largely due to this embargo on coverage, the UDT members and the Marine obsevers working with them as members of provisional reconnaissance teams were largely left out of the story. 

The product of dozens of photographic reconnaissance missions over Iwo Jima (left) by Navy and Army Air Corps pilots, relief maps made of rubber and plaster of paris like the one on the right were produced by the dozens for pilots bombing the island's two airfields (with a third under construction) in the months before the invasion. Planners of the invasion as well as those providing naval gunfire support to the thousands of Marines who stormed ashore on D-Day, February 19, 1945, also made use of the finely-detailed topographical maps.  However, there were not similarly-detailed charts of the underwater environment immediately off the invasion beach.  That is, until Underwater Demolition Team (UDT) swimmers and reconnaissance Marines charted it two days before D-Day, or "D minus two." (Naval History and Heritage Command images)

It is said that, during his 1853-55 journey to Japan Commodore Matthew Perry named the seven and a half square-mile volcanic island about 670 miles south of Tokyo, "Sulfur Island." A few decades later, the Tokyo Prefectural Government assumed control over the island, which by then was known by its Japanese translation, Iwo Shima. Its strategic importance had been long recognized, and the island was kept off-limits to foreigners well before the Second World War.  Like many Japanese possessions in the Pacific, intelligence was scant about the island compared to that known before earlier amphibous landings such as those that took place in Normandy the summer before.

Had the Americans a good source of intellligence on the island, they would have discovered that, from the time of the attack on Pearl Harbor in December 1941 until February 1944, Iwo Jima only hosted a garrison about 1,500 men and 20 aircraft.

By then, however, the noose was tightening on the Empire. In his book Iwo Jima Recon: The U.S. Navy at War, February 17, 1945 (2007),  Dick Camp, then the Deputy Director of the History Division of Marine Corps University, wrote, “The American victories in the spring and summer of 1944–Saipan, Guam and Tinian–had brought American forces within effective striking range of the Japanese Emprire itself.  Iwo Jima represented more than just another island defense: it was part of the homeland and a symbol of resistance.”

Major Yokasuka Horie, who had been stationed on Iwo Jima in 1944 and was later transferred to Chichi Jima, another island in the same chain that stretched northward towards Tokyo, wrote, "In those days we did not have any strong fortification on this island and it was as hazardous as a pile of eggs.  At that time if American forces has assaulted Iwo Jima, it would be completely occupied in two or three days."

Four high-ranking U.S. Officers, including Vice Admiral Richmond K. Turner (right), Commander-in-Chief of U.S. Operations on Iwo Jima, and Lieutenant General Holland M. Smith (second from right), Commander of U.S. Marines on the island, examine a scale model of Iwo Jima as they discuss plans for attacking the heavily defended island fortress. Such a high detailed model was made possible by excellent pre-invasion reconnaissance photographs from which every contour and characteristic of the terrain could be copied. Note, Rear Admiral Harry W. Hill, second to left, and Captain William H.P. Blandy, left. (Courtesy of the Library of Congress, PR13-CN-1991-34-28)

A herculean effort to bolster the island's defenses and increase the number of its defenders fourteen-fold took place during the following year.  Running thin on transport thanks to American unrestricted submarine warfare, the Japanese navy even resorted to transporting troops down the Volcano Island chain via fishing boats and even sailboats at a cost of 1,500 lost.  Digging tunnels around the clock, Japan's soldiers and sailors had created the strongest redoubt in the Empire.  

Despite the success of the preparations to bog the Americans down and borrow more time for the other home islands, Iwo's defenders were themselves living on borrowed time. "On February 1, 1945," recounted Horie, "for our 23,000 men (Army 17,500; Navy 5,500) on Iwo Jima we had about 70 days of grain and about 60 days of supplementary food..." Compounding the problem was the fact that Iwo Jima had no source of fresh water.

Based upon their close reading of American progress towards the Japanese home islands, the estimates on how much irreplaceable sustenance the defenders would need turned out to be pretty accurate.

White phosphorus rounds burst ashore as destroyers prepare for an Underwater Demolition Team operation off Iwo Jima's West Beach at 4:00 PM, February 17, 1945, during the pre-invasion bombardment of the island. Note the Fletcher-class destroyer firing at right. She appears to be painted in Camouflage Measure 32, Design 6D. Photographed from USS Texas (BB 35). (US Navy Photo 80-G-309163 via National Archives and Records Administration)

Thanks to surviving Japanese officers such as Maj. Horie, much is known of the defensive strategy of Lt.Gen. Kuribayshi, who adopted an attritive approach emphasizing the wearing down of invading forces gradually, rather than mounting a counterattack on D-Day designed to drive them back into the sea.  It would be wrong, however, to presume that this meant the Japanese defenders wouldn't make the approach to the beach as costly as possible.  The men of the Gunfire and Covering Task Force (TF 54) learned this the hard way on midmorning of the 17th, D-2, when the battleship Tennessee (BB 43) and the cruiser Pensacola (CA 24) took fire from shore batteries.  Pensacola took six hits in a matter of minutes from a 15-centimeter battery.  Pensacola's combat information center took a direct hit as well as one of her planes and five-inch guns.  Seventeen crew members were killed, including her executive officer, and 120 were wounded.

Anti-aircraft gunfire over Iwo Jima during the pre-invasion bombardment and minesweeping phase of the operation, circa February 17-18, 1945. Note what appears to be a burning airplane low over the ground at right, Mount Suribachi in the center and minesweepers (an AM and three YMS) at work at left. (NH 104144, Naval History and Heritage Command)

While this was going on, 12 tiny minesweepers of Task Group 52.3, the mine task group, closed to 5,000 yards of the island's southwestern coast protected by a line of seven destroyers parallel to the invasion beach only 3,000 yards offshore.  At 1035, seven small Landing Craft Infantry Gunboats (LCI[G]) equipped with 4.5-inch rockets and Bofors 40mm guns crossed the destroyer line, line abreast, under a operation plan drawn up by Lieutenant Commander Draper L. Kauffman, who had led UDT operations during the invasions of Saipan, Tinian, and Guam.   Orienting themselves broadside to the beach, they opened fire at 1045, roughly 2,000 yards from the black cinder sands.  At that moment they came under intense fire from shore batteries that had somehow remained untouched during the months of aerial bombing and the previous day's continuous gunfire.  Every gunboat was hit, so five more that had been held back in reserve were sent in.  LCI(G) 474 barely made it back to the destroyer line before it rolled over and sank.  Another one, which had taken a direct hit to the bridge, raced out to sea out of control.   One of the destroyers, USS Leutze, also took a direct hit, paralyzing the captain instantly when shrapnel ripped into his neck, and wounded four others.

While the LCIs pounded away at the beach at their closest approach, UDT swimmers in wooden boxy-looking Landing Craft Personnel (Large) emerged from their wake and drew to 700 yards from the beach, where the frogmen would lower their rubber boats over the side and furiously paddle even closer in.  Despite the maelstrom of shrapnel, fire and smoke above their heads, the UDT mission was not about shooting.  It was about sounding out what was under them.  As a book called Battle Report:Victory in the Pacific, Vol. 5 (1946) put it:

The task of these brawny men, armed with only a knife and clothed only in swimming trunks, was a difficult and important one.  Feeling their way towards the beaches–sometimes even as far in as the breaking surf–they searched for shallow water mines and underwater obstacles, either man-made or natural; they took careful note of the beaches, the kind of sand, the slope of the bottom, the surf conditions; they noted the direction of the currents and surveyed the contour of the land.  With the information brought back by these swimmers, information impossible to obtain from photographs, the last pieces of the landing mosaic were fixed together. 

At 1155, the LCP(L)s came back to pick up the swimmers and withdraw past the covering fire of the heavily-armed LCI(G)s.  In just 45 minutes ten of the 12 gunboats had been badly damaged, with 43 dead and 152 wounded, a 30 percent casualty rate.  Yet only one man among the roughly 400 frogmen and 22 Marine observers who scouted the beach, Carpenter's Mate Edward W. Anderson, was unaccounted for.  The credit for this in large part resided with the steely resolve of the gunboat captains facing Iwo Jima's firepower in full flower.  Nine of the 12 gunboat captains received the Navy Cross after the battle.  Lieutenant Junior Grade Rufus B. Herring, while commanding LCI(G) 449, personally maintained the position of his gunboat, despite being twice critically wounded, as it provided covering fire for the UDT members.  Afterward, he was awarded the Medal of Honor.

That afternoon, the alternate landing beach on the southwestern side of the island was scheduled for survey by the UDT and Marine provisional reconnaissance team and they had to do it all over again.  Only two of the LCI(G)s from the morning's mission were fit to take part, however, so the destroyers had to make up for the shortfall.  Somehow the UDT teams skirted disaster once again, but later that evening the luck of the members of Underwater Demolition Team 15 ran out on the messdecks of the destroyer transport Blessman (APD 48) as a 500-pound bomb from a passing Betty bomber found its mark below decks.  Thirty-eight were killed and six wounded, about half from UDT 15. 

Lt. Cmdr. Kauffman compiled all the charts and by midnight on the 17th had made enough copies that, in his words, "As a result, every Marine commanding officer had in his hands on D-1 morning the charts of the beaches–what we'd found in the way of gun emplacements and the types of land behind the beaches.  I was told by quite a few Marines that you're always very apprehensive before a landing," Kauffman recalled, "and it gave the young Marines a little bit more comfortable feeling to know that other people had been in there a couple of days before and had come out alive.  It was a confidence factor."

USS New York (BB 34). Bombarding Japanese defenses on Iwo Jima, February 16, 1945. She has just fired the left-hand 14"/45 gun of Number Four turret. View looks aft, on the starboard side. Having served for over thirty years by that time, New York was present at the surrender of the German High Seas Fleet in November 1918, and provided gunfire support for Operation Torch off Morocco 24 years later.  (U.S. Navy Photograph 80-G-308952, National Archives and Records Administration via NHHC Photo Curator/Flickr)

The reconnaissance mission undertaken by Navy UDT and Marine observers might have given confidence to the Marines as a core part of their mission, but a side effect was to spread confusion amongst Iwo Jima's defenders.  Although D-Day was actually two days distant, to the Japanese soldiers peering out from their caves, from Private Shioiri at the southern end of the island to Lt. Gen Kuribayshi to the north, the American invasion expected for well over a year had begun. The UDT and Marine reconnaissance missions of the 17th convinced the Japanese on Iwo that D-Day had come, so the most powerful of their guns came out of hiding and were duly targeted the following day by the venerable 14-inch guns of some of the oldest, toughest battlewagons afloat. 

The rugged cliff above made this mighty Japanese emplacement at the foot of Mount Suribachi almost completely impregnable. This photograph of the wrecked gun was taken on the fifth day of the Iwo Jima struggle. Photograph released February 24, 1945. (U.S. Navy Photograph 80-G-304846, National Archives and Records Administration via NHHC Photo Curator/Flickr)

"Without this error by the Japanese," wrote Jeter A. Isley and Philip A. Crowl in The U.S. Marines and Amphibious War, Its Theory and Its Practice in the Pacific (1951), "it is probable that many threatening coast defense weapons would have remained to take a very heavy toll of men and supplies from the outset of the ship-to-shore movement.  This was unquestionably the most significant role ever played by the bold underwater swimmers and their close support gunboats in the course of the Pacific War."