America's Island Hopping Strategy Depended On The Fight At Tinian:

America's Island Hopping Strategy Depended On The Fight At Tinian:

A squabble between a general and an admiral led to “the most perfect amphibious operation of the Pacific War.”

Captain Silverthorn selected 20 swimmers from Company A and eight from Lieutenant Richard F. Burke’s UDT-7 to make the Yellow Beach reconnaissance. At 10:45 pm, under a cloudy sky that obscured the moon, the teams started for the beach. 

“When the rubber boats were approximately 500 yards off shore, two sharp reports resembling rifle fire and showing flashes were heard off the south end of the main Yellow Beach,” Major Jones said. “These were followed by two dull reports resembling the noise of mortars.” Under orders to remain covert, Jones ordered the boats to move north “and attempt to obtain hydrographic information from the reef.”

UDT-7 found floating mines in the approaches to the beach and a number of underwater boulders and potholes. On the flanks of the 125-yard-wide beach, swimmers observed almost insurmountable cliffs that were 20 to 25 feet high.

On the beach itself, Marines led by 2nd Lt. Donald F. Neff discovered that the Japanese had strung double-aproned barbed wire. Neff left his men at the high-water mark and, armed only with a knife, he worked his way through the wire to 30 yards inland to locate exit routes. As he crawled along, he could hear nearby Japanese work crews.

At one point, he saw three Japanese sentries peering down from a cliff overlooking the beach. They occasionally shined flashlights onto the beach but failed to spot the Marine officer. Neff found that the Japanese were preparing defenses sited directly at the proposed landing site. After a harrowing time ashore, he returned to his men and swam back to the rubber boat.  Neff was later awarded the Silver Star for leading Company A’s recon team that night.

Based on the reconnaissance, the commander of Task Force 52 stated: “Yellow Beach was found to have fairly heavy surf, and [was] unsuitable for a large body of troops because of the steep cliffs and narrow exits.” The landing, it was decided, would come only at White Beaches 1 and 2. Shinn split his company into two teams, one for White Beach 1 (the northernmost beach) and the other team for White Beach 2. 

“The beaches were about 60 yards and 160 yards,” recalled Brig. Gen. Russell E. Corey, who was a lieutenant at the time. The two were separated by 1,000 yards of rocky coast. At 11:30 pm, the two Marine teams disembarked from Gilmer.

“Debarkation went well until the LCRs were cast off from their tows,” Shinn said. A strong tidal current carried both teams north. The White Beach 1 team landed on a coral outcropping about 800 yards north of Tinian and never got ashore. If not for the coral outcrop, they would have been carried even farther into the Saipan Channel. 

The White Beach 2 team landed on White Beach 1 and made a hasty reconnaissance of the beach and its approaches. Meanwhile, the UDT swimmers scanned the water offshore, but did not find anything that would interfere with a landing. 

One group of frogmen, led by Lieutenant (j.g.) George Suhrland, crawled onto the beach above the high-water mark to check out a report that mines had been planted, but he found no explosives.

During the recovery, the northerly current, plus low scudding clouds and a light fog, made it extremely difficult to locate the rubber boats. Gunnery Sergeant Sam Lanford, Pfc. John Sebern, and Lt. Cmdr. Kauffman, the UDT commander, missed the recovery and were swept into the channel that separated Tinian from Saipan. They had to tread water for several hours before finally being rescued by USS Dickerson (APD-21), a picket boat patrolling the channel.  Fortunately, the men had stuffed flotation bladders in their jackets, which helped keep them afloat.

   With only half the mission accomplished, Jones assigned Silverthorn’s Company A to recon White Beach 2 the next night. “Arrangements were made to use the USS Stringham to land the troops and to use the USS Gilmer to pick them up,” Jones explained. “Five rubber boats with swimmers and paddlers and one drone rubber boat carrying a mounted tripod wrapped with wire mesh were towed to a point 1,900 yards off White Beach 2.” 

Jones blamed “the failure on the first night to a lack of surface radar on the Gilmer to guide the boats to the beach,” thus the improvised radar reflector. Company B furnished and manned the boats while Silverthorn supplied six two-man swimmer teams of one officer and one senior staff NCO. Twelve UDT swimmers also accompanied the recon team.

 “At 1,900 yards,” Jones said, “the rubber boats cast off and the ship guided them by radio. All the men in the LCRs had steel helmets and, together with the wire-mesh tripod, enabled the ship to guide the boats to a point 400 yards to seaward and 100 yards south of White Beach 2.” 

At that point, all the swimmer teams slipped into the water and made their way toward the beach, using either the sidestroke or the breaststroke to keep from splashing or making noise. They were almost invisible; only their heads were above water, and they had darkened their faces and necks with camouflage paint. The water over the reef was deep enough for the men to traverse without exposing themselves to observation, although several swimmers were cut by the sharp coral.

Once ashore, the recon Marines quickly determined that there were no obstacles on the beach, nor any evidence of Japanese activity. While the Marines worked the beach, the UDT scanned the water and the reef fronting the shoreline. At one point, a Japanese sentry almost stepped on two team members as they lay exposed on the sand, but they were not discovered. 

Silverthorn noted, “A very thorough reconnaissance of the surf conditions, reef, beach, and flanks was done.” The teams completed their assignments and returned to the recovery ships on time. Silverthorn then briefed Rear Admiral Hill on the results of the reconnaissance: “Admiral, the beaches are narrow [but] there are no mines, no coral heads, no boulders, no wire, no boat obstacles, and no offshore reefs. The beaches are as flat as a billiard table!” 

That sold Hill.  He acknowledged, “You have convinced me.” For his leadership, Silverthorn was also awarded the Silver Star.

The landing force operations officer summarized the work and results of the amphibious reconnaissance: “This was an extremely difficult operation that was almost perfectly executed, and the perfection of the execution is due both to the high competence of the reconnaissance battalion and the underwater demolition team….”

Rear Admiral Hill, having been forcefully rebuffed by Vice Admiral Turner, kicked the beach decision up to Admiral Spruance, who called a meeting of the primary commanders on the afternoon of July 12. Lt. Gen. Smith and Rear Admiral Hill strongly argued the case for the White Beaches. At the conclusion of the presentation, Turner calmly and nonchalantly announced that he would accept the plan. 

A participant later wrote, “We were all surprised at the unexpected rapidity and ease with which the plan was presented and accepted.” Hill noted, “What a great relief that was for us all.”  Turner remarked, “Before the reconnaissance … I had tentatively decided to accept the White Beaches unless the reconnaissance reports were decidedly unfavorable.”

Turner shrugged off criticism of his early intransigence. “I merely insisted that full study and consideration be given, before decision, to all possible landing places … all of them difficult for more than one reason. And, in accordance with an invariable custom, I refused to give a decision until such studies had been made, and also until the main features of the landing plan had been developed.”

On July 24, the assault elements of Maj. Gen. Clifton Cates’ 4th Marine Division landed successfully across the White Beaches with minimum casualties by mid-afternoon. The next day, the 2nd Marine Division came ashore over the same beaches. Both divisions had suffered heavy casualties during the Saipan operation and were not eager for another slugging match.

The 2nd Marine Division had been especially hard hit over the last 18 months, beginning with Guadalcanal where it had suffered 1,000 casualties, while an additional 12,000 men had come down with malaria. Nine months later, the division had gone through hell at Tarawa, where it had lost 3,200 men, including nearly 1,000 dead. A third island invasion—at Saipan in June and July 1944—ended in victory but also with another 1,300 Marines killed and 5,000 wounded. About 29,000 Japanese troops died.

The 4th Marine Division was relatively new but had been blooded at Roi-Namur in the Marshall Islands in January and February 1944, where it suffered moderate casualties—fewer than 800 men. During the Battle of Saipan, it lost 6,000, including about 1,000 dead. The Tinian landing would be its third in a little over six months and would be the first under a new divisional commander—Maj. Gen. Cates.

The 4th Division’s battalions were seriously understrength; they had been depleted at Saipan, and their average strength was now down from 880 men to just 565 men—a drop of more than 35 percent.