IJN Submarine I-373: Tabular Record of Movement

2001-2014 Bob Hackett & Sander Kingsepp
Revision 3

15 August 1944:
Laid down at Yokosuka Navy Yard as a Type D-2 "Tei-Kai-gata" transport submarine No. 2962.

5 October 1944:
Numbered I-373 and provisionally attached to Yokosuka Naval District.

30 November 1944:
) Launched.

14 April 1945:
I-373 is completed, commissioned in the IJN and attached to Yokosuka Naval District. LtCdr (Cdr, posthumously) Inobe Yukio (66)(former torpedo officer RO-115) is the CO. Assigned to SubRon 11 for working-up.

1 May 1945:
Vice Admiral Daigo Tadashige assumes command of the Sixth Fleet (Submarines).

16 June 1945:
Departs Yokosuka.[1]

17 June 1945:
Arrives at Sasebo. I-373 is converted to carry aviation fuel.

20 June 1945:
Reassigned to SubDiv 15, Sixth Fleet.

9 August 1945:
I-373 departs Sasebo on her first tanker run to Formosa.

13 August 1945:
East China Sea. LtCdr Inobu is zigzagging on a SW base course at 10 knots when I-373 is picked up by Cdr R. R. Managhan's USS SPIKEFISH (SS-404) SJ radar. A few minutes later, SPIKEFISH makes visual contact. Managhan begins tracking only to lose contact after about an hour when Inobu submerges.

14 August 1945:
190 miles SE of Shanghai. SPIKEFISH regains radar contact two hours later at 8, 600 yards and tracks the target until morning when it is sighted on the surface. The silhouette identifies the target to be a large I-class submarine. Cdr Managhan fires a full salvo of six bow torpedoes and obtains two hits that sink I-373 by the stern at 29-02N, 123-53E. SPIKEFISH picks up one survivor of I-373's crew of 85. The survivor claims that his submarine was I-382 (no such sub).

I-373 is the last Japanese submarine sunk in World War II.

15 September 1945:
Removed from the Navy List.

Authors' Note:
[1] Several FRUMEL intercepts suggest that I-373 might have made a supply run from Sasebo to Takao and back between the 3rd and the 26th July. This is not confirmed by Japanese sources.

Special thanks go to Hans Mcilveen of the Netherlands for info on FRUMEL intercepts.Thanks also go to Dr. Higuchi Tatsuhiro of Japan.

Bob Hackett and Sander Kingsepp.

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