Upon commissioning, I-372 was attached to the Sasebo Naval District and was assigned to Submarine Squadron 11 for workups.[2] She was reassigned to Submarine Squadron 7 on 8 January 1945.[2]
The Japanese next considered sending I-372toIwo Jima with a cargo of artilleryshells, but abandoned the idea.[2] Instead, on 16 February 1945 I-372 began conversion at the Kure Naval Arsenal into a tanker submarine capable of carrying 90 metric tonsofaviation 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 Alliedsignals 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-372onradar 7 nautical miles (13 km; 8.1 mi) northwest of Wake.[2]I-372′sradar detector failed to detect Sea Owl′s radar signal, and I-372anchored 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]
Hostilities between Japan and the Allies came to an end on 15 August 1945, and in September 1945 U.S. Navy divers from the submarine tenderUSS Proteus (AS-19) inspected I-372′s wreck.[2] The Japanese struck her from the Navy list on 15 September 1945.[2] In August 1946 the wreck was refloated, towed into deep water, and scuttled.[2]
Japan
