In response to the “unacceptable” numbers of Marines killed in November 1943’s Battle of Tarawa, Navy leaders ordered the creation of nine underwater demolition teams to clear the path for future amphibious landings in the Pacific Theater
By the time they had targeted Iwo Jima in their island-hopping campaign toward Tokyo, Navy leaders had decided that “frogmen” would lead the way in amphibious landings. These volunteer sailors were specially trained and possessed “physical strength, endurance, swimming ability, courage, coolness and good judgment.”
They began probing the Iwo Jima beaches on Feb. 17, 1945 — two days before the main invasion. Four underwater demolition teams (UDTs) — 12, 13, 14 and 15 — comprising about 100 swimmers were dropped off by small boats called Landing Craft, Personnel Ramped (LCPRs) within 700 yards of the beach.
The frogmen swam to the shore to gather intelligence about beach and surf conditions, clear all mines and obstacles, gather sand samples in small tobacco sacks and take note of Japanese defenses.
A group of 22 Marines from the 5th Reconnaissance Detachment were assigned to accompany the teams to take photographs of the beach.
Team 12 was responsible for Red Beach One and Two; Team 13, Green Beach One; Team 14, Yellow Beach One and Two; and Team 15, Blue Beach One and Two.
The teams had an hour to complete their mission before being picked up and returned to their High-Speed Transport ships, or APDs.
The second part of the mission was to reconnoiter the western beaches in the late afternoon.
‘Synchronize Watches. Muster on the Fantail.’
On the morning of Feb. 17, the swimmers prepared for the mission.
They coated their faces, shoulders and arms with grey-blue paint as camouflage and cocoa butter or heavy grease to ward off the chilly 59-degree water temperature. They traveled light — swim trunks, face masks, fins and Ka-Bar combat knives. Other equipment included Tetryl (explosives) demolition packs, mine detectors, markers to record observations and devices for determining water depth.
A member of Team 15 recalled exactly how their mission began with orders over the loud speaker: “Synchronize watches. Muster on the fantail,” according to A History of UDT 15.
Then the LCPRs were lowered from the APDs, the teams boarded and they headed for the beach. A total of 12 LCI (infantry landing craft) gunboats were assigned to cover the UDTs by bombarding the beaches with gunfire and rockets.
The LCIs came under withering fire, according to unidentified participants in A History of UDT 15.
“Gunfire splashed all around us, mortars and heavy shells, which doused us,” a frogman later reported. “The noise even underwater was deafening, and the metal falling around was terrifying. The idea was to run a chart of the beach to determine its slope. We were also looking for obstacles and mines.”
Several men crept up on the beach to get samples of the coarse sand.
“We took a little fire doing that, but we got our samples and swam back out,” another frogman noted.
The samples were needed to determine if the beach would support vehicles. As later discovered, it did not and caused congestion when many vehicles bogged down in the coarse sand.
At 11:55 a.m., as LCPRs raced along the beach line at 16 knots, the pickup started. The “catchers” snagged the tired swimmers with a rubber ring.
“We hooked their arms and swung them aboard,” recalled one sailor. The frogmen suffered only one fatality. Motor Machinist’s Mate 3rd Class Frank W. Sumpter was shot in the head and died later of his wounds.
Relaxation Turns to Tragedy
Because the LCIs had taken such a severe beating suffering 30 percent casualties to their crews with one craft sunk and 11 damaged, U.S. commanders decided that the afternoon mission would be supported by battleships and air. The mission went smoothly, unlike the morning session.
The swimmers were able to accomplish their afternoon tasks without casualties. As the swimmers reached the dropoff point, one of the support planes laid a smoke screen the length of the beach.
“We could see the gun emplacements on the beach,” said Arthur D. Hettema, a Seabee and member of Team 15. “After several surface dives to look for possible electric cables connected to mines, we swam to the breaker line.”
At the end of their mission, the UDTs returned to their respective ships. For Team 15 that was USS Blessman (APD48), a former destroyer escort.
On the evening of Feb. 17, the mess hall of the Blessman was filled with crewmen and frogmen relaxing after their stressful encounter with Japanese artillery. Some were playing cards, while others were drinking coffee or writing letters.
Suddenly around 9:21 p.m., a prowling Japanese aircraft spotted the luminescent wake of the Blessman and released a bomb, which penetrated through the deck, destroying the mess hall, galley and number one engine room. It left a 40-by60-foot hole in the main deck.
Disoriented by the resulting fire and smoke, the men struggled to escape from below deck. About 11 p.m., the USS Gilmer (APD-11) arrived to prevent the fire from detonating the tons of explosives on board and to assist with the casualties.
A total of 40 troops were killed, including 15 frogmen, and at least 34 were wounded. The dead were buried at sea as the captain read the burial rites.
Three officers received Bronze Stars for their courageous evacuation of the wounded in spite of imminent danger of fire reaching the explosives.
According to the after-action report written by H. F. Brooks, the frogmen at Iwo Jima “were gallant under the mortar and small-arms fire as they made their reconnaissance right up to the water’s edge. All exhibited an eagerness to carry out their mission.”
This article is featured in the February 2020 issue of VFW magazine, and was written by Dick Camp and Suzanne Pool Camp. Richard "Dick" Camp and his wife, Suzanne, reside in Fredericksburg, Virginia. Richard, a former Marine who served in Vietnam, is the author of 16 books.