Japanese submarine I-372

On 8 February 1945, I-372 departed Yokosuka bound for Takao on Formosa.[2] She was then to rescue Imperial Japanese Army Air Force pilots stranded at Batulinao in the Aparri area of northern Luzon in the Philippine Islands as a result of Japanese setbacks in the Philippines campaign, but after the submarines Ro-112 and Ro-113 were lost attempting to pick up the pilots, she received orders to abort the mission and return to Japan.[2] She arrived at Kure on 14 February 1945.[2]

The Japanese next considered sending I-372 to Iwo Jima with a cargo of artillery shells, but abandoned the idea.[2] Instead, on 16 February 1945 I-372 began conversion at Kure Navy Yard into a tanker submarine capable of carrying 90 metric tons of aviation gasoline.[2] During her conversion, she probably also had a submarine snorkel installed.[2] In mid-March 1945 she moved to Yokosuka, and on 20 March 1945 Submarine Squadron 7 was deactivated and she was reassigned to Submarine Division 16 along with the submarines I-369, Ha-101, Ha-102, and Ha-104.[2]

On 1 April 1945, I-372 departed Yokosuka on a supply voyage to Wake Island.[2] On 4 April 1945, Fleet Radio Unit, Melbourne (FRUMEL), an Allied signals intelligence unit headquartered at Melbourne, Australia, reported that it had intercepted and decrypted Japanese signal traffic indicating that a Japanese submarine would arrive at Wake Island on 17 April 1945 and begin several nights of unloading and loading operations there.[2] The United States Navy submarine USS Sea Owl (SS-405) was alerted to this at 04:00 on 16 April 1945 via an Ultra intelligence signal from Guam and moved to intercept the Japanese submarine.[2]

On 18 April 1945, Sea Owl detected I-372 on radar 7 nautical miles (13 km; 8.1 mi) northwest of Wake.[2] I-372′s radar detector failed to detect Sea Owl′s radar signal, and I-372 anchored at Wake without her crew realizing that any Allied forces were in the area.[2] Sea Owl approached the anchorage and fired three torpedoes at I-372 at a range of 1,600 yards (1,500 m).[2] Two of them failed to detonate, and the third missed I-372 but destroyed Wake Island's pier.[2] I-372 crash-dived, and after World War II the U.S. Joint Army-Navy Assessment Committee erroneously credited Sea Owl with sinking the submarine Ro-56 that day.[2]

I-372 did not surface again until 19 April 1945, when she finished unloading her cargo — which included enough rice to feed Wake Island's garrison for ten days — and embarked 29 passengers.[2] She then got underway for Yokosuka, which she reached on 29 April 1945.[2]

I-372′s next supply run also was to Wake Island. She departed Yokosuka on 15 June 1945,[2] and FRUMEL again detected her movements, reporting that day that "A Japanese submarine left Tokyo Bay at 09:00 on 15th [June 1944] to pass 5 nautical miles (9.3 km; 5.8 mi) south of Nojima Saki at 20:00 on passage to Wake Island."[2] She avoided interception by Allied forces, however, and arrived at Wake on 28 June 1945, unloaded her cargo, and headed back to Yokosuka, where she arrived on 10 July 1945.[2]

During an air raid on Yokosuka by U.S. Navy Task Force 38 aircraft on 18 July 1945, I-372 came under attack by TBM Avenger torpedo bombers and F6F Hellcat fighters from the aircraft carriers USS Essex (CV-9), USS Randolph (CV-15), USS Shangri-La (CV-38), and USS Belleau Wood (CVL-24).[2] The attack killed one member of her crew, and a bomb that landed close aboard ruptured her starboard cargo hold.[2] She slowly sank.[2] Deemed beyond salvage, she was abandoned.[2]