One of the kaiten’s few achievements against a US warship came on July 24, 1945. USS Underhill (DE-682) had been commissioned in Boston in 1943, one of the vast number of Buckley-class destroyer escorts completed during the war. She had served out most of the conflict as a member of Escort Division 56 in the Atlantic, Caribbean, and Mediterranean.

In January, 1945, she was transferred to the Pacific and assigned to the Seventh Fleet (also known as ‘MacArthur’s Navy’). On July 24, she was escorting a convoy of LSTs loaded with troops of the Army’s 96th Infantry Division. Having seen heavy combat on Okinawa, these troops were on their way to a rear area in the Philippines for R&R. However, in the early afternoon, while still some 150 miles northeast of Luzon, the convoy was sighted by Commander Saichi Oba, commanding the Japanese submarine I-53.The I-53 was a wartime design, having been launched from Kure Naval Dockyard in 1943, and commissioned in February 1944. She was a member of the C(3)-Class of long-range cruising submarines. During her brief conventional career,I-53 participated in operation "A-Go", being assigned a patrol area north of the Admiralty Islands, in May 1944.She was assigned sentry duty east of the Marianas, in mid-June 1944, and did not contribute to the Philippine Sea Battle. She was then modified as a kaiten carrier. Her war load then comprised 6 kaitens, as well as her normal complement of torpedoes.

Commander Oba (Etajima class of 1935), had previously commanded RO-105, RO-49, I-162, and latest of all, I-53.Under his command, I-53 took part in the second Kaiten mission, "Kongo." She was unable to launch any of the four kaitens she carried and was forced to return to Japan with her disappointed crew. "Tamon", her second and last Kaiten mission, was a different story. According to conflicting accounts, I-53 is credited having either damaged one transport, or sunk three transports and a destroyer through conventional torpedo attacks. When she sighted Underhill’s convoy, two of I-53’s kaiten’s had been rendered inoperable due to mechanical failure. Most reports indicate that she then launched her four remaining kaitens (although some say that only two were launched). These craft were probably manned by Sub-lieutenant Jun Katsuyama, Ensign Toyooki Seki and Flight Petty Officers 1st Class Tsutoma Kawajiri and Masahiro Arakawa.

During the ensuing battle, Underhill conducted a depth-charge attack which seems to have accounted for one of the attacking craft. The Underhill also apparently rammed and sank at least one other of the attacking kaitens However, shortly thereafter, at 1515 hours her luck ran out and she was struck by a third suicide craft, which rammed home on the starboard bow just forward of Engine Room #1.The results were catastrophic. The destruction caused by the kaiten’s 3000+ lb. warhead was amplified by the simultaneous explosion of the forward boilers, as well as (it is suspected) the ready ammunition for the forward 3"and 20mm guns. The resulting explosion blew the ship completely in two. The forward portion sank almost instantly, with no survivors.
The rear section remained afloat, although there were casualties aft as well, including one sailor crushed by the SL radar antennae, which was blown off the top of the mainmast and landed on him near the stern.

Many of the dazed survivors spent several hours in the water nearby, as the other escorts continued to fire on suspected kaitens (and perhaps the I-53 as well). Eventually, all the survivors were brought aboard by PC-803 and PC-804, and the Underhill’s remaining half was taken under fire by U.S. warships and sunk. In all, 112 of Underhill’s crew of 238 lost their lives in the attack. Commander Oba brought the I-53 back to Hikari(Scanned from Fukui, "Japanese Naval Vessels at the End of World War II") exactly a month after the attack on the Underhill, and well after the Armistice. I-53 was subsequently scuttled by the U.S. Navy off of Goto, Japan, on April 1, 1946. Commander Oba served with the Japanese Maritime Self-Defense Force as a Captain until his retirement. The survivors of the USS Underhill gather at the US Naval Academy on an annual basis to memorialize their ship and their lost shipmates. The wooden organ case located in the Main Chapel at the Academy was a gift from the survivors of the Underhill in memorial to those who died during the attack.

Compiled by Rodger Crum and Jon Parshal