Service history
Upon commissioning, I-373 was attached formally to the Yokosuka Naval District and was assigned to Submarine Squadron 11 for workups. [2] On 16 June 1945, she departed Yokosuka bound for Sasebo. [2] Arriving at Sasebo on 17 June 1945, she began conversion into a tanker submarine capable of carrying 150 metric tons of aviation gasoline in addition to other cargo. [2] On 20 June 1945, she was reassigned to Submarine Division 15 in the 6th Fleet. [2]
Transport operations
Fleet Radio Unit, Melbourne (FRUMEL), an Allied signals intelligence unit headquartered at Melbourne, Australia, reported that it had intercepted and decrypted signals that indicated that I-373 departed Sasebo on a supply run to Takao on Formosa on 3 July 1945 and returned to Sasebo on 26 July 1945, but post-World War II examination of Japanese records has not corroborated FRUMEL's reporting. [2]
On 5 August 1945, FRUMEL reported that it had intercepted and decrypted a Japanese signal indicating that I-373 would depart Sasebo that day bound for Takao and would return with a cargo of aviation gasoline, rice, and sugar. [2] In fact, I-373 got underway from Sasebo on 9 August 1945 headed for Takao. [2]
Loss
At 20:10 on 13 August 1945, I-373 was on the surface in the East China Sea 200 nautical miles (370 km; 230 mi) southeast of Shanghai, China, making 10 knots (19 km/h; 12 mph) and zigzagging around a base course of 230 degrees true when the United States Navy submarine USS Spikefish (SS-404) detected her on radar. [2] Spikefish′s radar detector also detected the pulse of I-373′s Type 13 air-search radar. [2] Spikefish closed the range, sighted I-373 at a range of 3,500 yards (3,200 m) at 20:18, and tracked her for an hour, but lost visual contact at 21:18 when I-373 feinted to the southeast and then submerged. [2]
At 00:07 on 14 August 1945, Spikefish regained radar contact on I-373 at a range of 8,600 yards (7,900 m) and began tracking her again, finally confirming that I-373 was a Japanese submarine at 04:19. [2] At 04:24, Spikefish fired a spread of six Mark 14 Mod 3A torpedoes at a range of 1,300 yards (1,200 m). [2] Two hit I-373, which sank by the stern at 29°02′N123°53′E / 29.033°N 123.883°E / 29.033; 123.883 (I-373) . [2] Spikefish′s sound operator reported hearing loud sounds of air escaping from the sinking I-373. [2]
Spikefish surfaced, and at 05:40 she passed through a thick slick of diesel fuel and a large amount of floating debris. [2] She found five survivors in the water, all of whom refused rescue. [2] She left four of them to perish in the water but forcibly brought one of them aboard. [2] The sole survivor of I-373, he misidentified her to Spikefish′s crew as the nonexistent submarine "I-382." [2]
Eighty-four men died in the sinking of I-373, the last Japanese submarine lost in World War II, which ended the next day. [2] The Japanese removed her from the Navy list on 15 September 1945. [2]
USS Spikefish (SS/AGSS-404), a Balao-class submarine, was a ship of the United States Navy, named for the spikefish. She was the first United States submarine to record 10,000 dives.
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Japan
