IJN Patrol Boat No. 31:
Tabular Record of Movement

© 2007-2018 Bob Hackett, Sander Kingsepp and Peter Cundall
Revision 8

A MOMI-class destroyer is ordered from Kawasaki Heavy Industies Ltd.

24 May 1919:
The destroyer is designated KIKU.

Kobe. Laid down.

13 October 1920:

10 December 1920:
Completed and registered in the IJN. Assigned to DesRon 14.

1 November 1926:
LtCdr (later Vice Admiral) Nishimura Shoji (39) assumes command.

1 November 1927:
An unknown officer assumes command.

30 November 1929:
LtCdr (later Vice Admiral) Nakagawa Ko (42) assumes command.

1 November 1930:
Lt (later Rear Admiral) Shimizu Toshio (46) assumes command.

1 December 1930:
Lt Shimizu is promoted LtCdr.

24 October 1931:
An unknown officer assumes command.

7 July 1937: The Marco Polo Bridge (The"First China Incident") Incident:
Hun River, Lukuokiao, China. After night maneuvers at the bridge, the Japanese discover a soldier missing and assume the Chinese captured him. They demand entry to a suburb of Peking (Beijing) to look for him, but the Chinese refuse. The Japanese shell the city and an undeclared war begins. Soon thereafter, KIKU and sister destroyer AOI are dispatched to northern China.

10 December 1939:
KIKU is transferred from DesRon 14 to the Reserve.

December 1939:
Kure Naval Arsenal. One of three Kampon boilers is removed reducing speed to 18 knots. Additionally, her torpedo tubes, aft 4.7-inch/45 cal main gun and minesweeping gear are removed. 25mm AA guns and depth charge racks and throwers are fitted. Extra ballast is added to compensate for the loss of topside weight and to increase stability. The changes increase her displacement to 935-tons.

1 April 1940:
Reclassified as a patrol boat and renumbered PB-31.

5 September 1942:
PB-46 and PB-31 escort tanker NISSHIN MARU No. 2 north through the Bungo Straits.

E 6 September 1942:
The escorts are detached.

19 October 1942:
Patrol boat PB-31 meets up and starts escorting oiler NOTORO through the Bungo Straits. PB-31 ends the escort off Fukushima.

3 January 1943:
Cable layer escort TSURUSHIMA and patrol boat PB-31 depart Saeki escorting convoy "S" (No. 8 Military Movement) consisting of KOSHU MARU No. 2, ASAKA, NISHIYAMA (SEIZAN), IWATE, IKOMA, HOKO MARUs.

E 4 January 1943:
The escorts are detached at 29N.

6 January 1943:
At 0315 arrives to assist cable layer escort TSURUSHIMA 175 degrees 50 miles from Okinoshima Lighthouse which has sighted an enemy submarine. At 0650 ceases the hunt.

17 January 1943:
Departs Saeki escorting convoy "U "consisting of YAMATO, MEIKAI, MOMOHA, INDUS, NAGANO and KIRIHA MARUs escorted by patrol boat PB-31 and subchaser CH-36.

E 19 January 1943:
At 29 degrees N, the two escorts are detached from the convoy.

22 January 1943:
Departs Yokosuka escorting auxiliary oiler NISSHIN MARU. At 1600 off the coast of Sunosaki subchaser CH-33 joins the escort. Near the 33 degree north latitude PB-31 ends the escort.

3 February 1943:
Departs Saiki and patrols the Bungo Suido.

7 February 1943:
Arrives at Kure.

9 February 1943:
Departs Kure and patrols the Bungo Suido.

15 February 1943:
Arrives at Saiki.

17 February 1943:
Departs Saiki but returns later that day.

18 February 1943:
Departs Saiki.

19 February 1943:
Returns to Saiki and later that day departs and patrols the Bungo Suido.

21 February 1943:
Departs Saiki in C-2 Convoy, No.8 Military Movement consisting of MIYAURA, ADEN, ROKKOSAN, HAKUSAN and TATEISHI MARUs escorted by PB-31 and minelayer NASAMI. (The convoy left Moji on 18 February)

E 22 February 1943:
At 28.50N the escorts detach.

25 February 1943:
Arrives at Saiki.

27 February 1943:
Departs Saiki and patrols the Bungo Suido.

4 March 1943:
Arrives at Kure escorting auxiliary submarine tender YASUKINI MARU.

7 March 1943:
At Ariake Bay (Shibushi Wan), Cable layer TSURUSHIMA and subchaser CH-36, patrol boat PB-31, minelayer NATSUSHIMA and auxiliary minesweeper TAMA MARU No. 7 escort damaged transport CLYDE MARU north.

11 March 1943:
PB-46, PB-31, torpedo boat HATO, minelayer NUWAJIMA and subchaser CH-36 escort battleship HARUNA from Osumi Kaikyo to Okinoshima.

12 March 1943:
Escorts the auxiliary seaplane carrier KIYOKAWA MARU north through the Bungo Suido.

18 March 1943:
Switches to patrolling the southern entrance to the Bungo Suido.

23 March 1943:
Arrives at Kure.

29 March 1943:
Meets up with Navy oiler ASHIZURI and escorts the ship north to Fukajima, where PB-31 is detached.

1 April 1943:
Departs Saiki.

2 April 1943:
Arrives back at Saiki.

3 April 1943:
Departs Saiki escorting a convoy.

5 April 1943:
Arrives back at Saiki.

6 April 1943:
Departs Saiki.

7 April 1943:
Arrives back at Saiki.

9 April 1943:
Departs Saiki.

10 April 1943:
Off Fukajima meets up with Navy oiler ASHIZURI which is escorted to 133E.

11 April 1943:
Arrives back at Saiki.

16 April 1943:
Departs Saiki.

18 April 1943:
Arrives back at Saiki.

19 April 1943:
Departs Saiki.

22 April 1943:
Arrives back at Saiki.

24 April 1943:
Departs Saiki and later arrives at Kure. Drydocked.

21 May 1943:

23 May 1943:
Departs Kure and later that day arrives at Saiki.

25 May 1943:
At 0600 departs Saiki with auxiliary minesweeper TAKUNAN MARU No. 8 escorting convoy K-525 consisting of TAGA, NICHIRYO, TOYOOKA, TAGANOURA and DELAGOA MARUs and SHINTO MARU No. 1. The convoy sails at 9 knots.

E 26 May 1943:
At 29N TAKUNAN MARU No. 8 is detached.

2 June 1943:
Arrives at Palau.

8 June 1943:
At 2020, PB-31 departs Palau for Moji with torpedo boat HATO and minelayers NUWAJIMA amd YURISHIMA escorting convoy P-607 consisting of HOFUKU, KAHOKU, HIYOSHI and SAIPAN MARUs. At about 0240, LtCdr (later Vice Admiral) John A. Tyree's USS FINBACK (SS-230) torpedoes and damages KAHOKU MARU, but she does not sink and continues on. USS FINBACK makes two more attacks over the next two hours and gets another hit. At 0950, KAHOKU MARU loses her battle with flooding and goes down. During Tyree's attacks, he also hits SAIPAN MARU, but the Mark-14 torpedo is a dud.

13 June 1943:
The convoy arrives at Moji. PB-31 detaches and arrives at Saiki.

20 June 1943:
PB-31 departs Saiki on patrol.

23 June 1943:
Arrives back at Saiki.

26 June 1943:
At 0800, PB-31 and minesweeper W-31 depart Saeki escorting convoy O-503 consisting of NICHIZUI, TATSUMIYA and HAVRE MARUs.

2 July 1943:
Arrives at Palau.

6 July 1943:
Departs Palau.

8 July 1943:
Returns to Palau.

11 July 1943:
Departs Palau escorting a convoy.

13 July 1943:
Arrives back at Palau.

14 July 1943:
Departs Palau escorting convoy FU-406 consisting of YAMAFUKU, TAGA, YAMAGATA, RYUYO, UMEKAWA and OLYMPIC MARUs.

E 22 July 1943:
Minelayer NUWAJIMA and auxiliary minesweeper TAKUNAN MARU No. 3 join escort at 30-00N 134-00E.

23 July 1943:
Arrives at Saiki.

30 July 1943:
At 0900, PB-31 departs Saiki for Palau with minelayer YURISHIMA and auxiliary minesweeper TAKUNAN MARU No. 3 escorting convoy No. O-003 consisting of TAISHO, TOYOKAWA and DELAGOA MARUs. At latitude 29N, YURISHIMA and TAKUNAN MARU No. 3 are detached to return to Saiki.

8 August 1943:
Arrives at Palau.

13 August 1943:
Departs Palau with auxiliary minesweeper TAKASAGO MARU escorting convoy FU-207 consisting of KANAYAMASAN, CHINZEI, TONEI, SHOKO, HAKKO, TOKO, MYOGI, TAIKO and UCHIDE MARUs. The convoy sails at 9 knots.

E 15 August 1943:
At 10N TAKASAGO MARU is detached and returns to Palau.

E 20 August 1943:
At 39-20N 133-08E auxiliary minesweepers TAKUNAN MARU No. 8 and TAKUNAN MARU No. 3 meet up with the convoy.

21 August 1943:
Arrives at Saiki.

22 August 1943:
Departs Saiki and later that day arrives at Kure.

31 August 1943:
Departs Kure and later that day arrives at Saiki.

3 September 1943:
PB-31, minesweeper W-33 and auxiliary minesweeper YACHIYO MARU depart Saiki escorting convoy O-302 consisting of CHINZEI and TOYOKAWA MARUs.

E 4 September 1943:
At 30N YACHIYO MARU is detached and later that day at 29N W-33 is detached.

13 September 1943:
Arrives at Palau.

18 September 1943:
Departs Palau escorting convoy FU-807 consisting of KEMBU (ex British EMPIRE BLOSSOM), NICHIAI, ASOSAN, SHICHISEI and KURAMASAN MARUs, SHINSEI MARU No. 1 and SHINSEI MARU No. 17. The convoy sails at 8.5 knots.

E 26 September 1943:
At 30N 134E the convoy is met by auxiliary minesweepers OI and TAMA MARUs and TAMA MARU No. 7. Later the convoy arrives off Fukajima and is dissolved.

8 October 1943:
Departs Kure on an escort mission.

10 October 1943:
Arrives at Saiki.

12 October 1943:
Departs Saiki escorting convoy O-205 consisting of TAISHO, KURAMASAN, NAPLES, TOSHO and SAIHO MARUs.

22 October 1943:
At 0900 arrives at Palau.

26 October 1943:
At 1100, PB-31 departs Palau for Saiki escorting convoy FU-607 consisting of NANMAN, MEXICO, NISSHU, KAYO MARUs and JUISSEI MARUs (the latter often referred to as HOSHI MARU No. 11) and probably KURAMASAN and TOSHO MARUs. [4]

At 30N, minelayers YURIJIMA and NUWAJIMA and auxiliary minesweepers AOI MARU, YACHIYO MARU and TOKUHO MARU No. 10 join the convoy.

27 October 1943:
At about 2200, LtCdr Frank T. Watkins' USS FLYING FISH (SS-229) torpedoes and sinks NANMAN MARU at 12-02N, 134-28E.

28 October 1943:
At 0232, USN codebreakers intercept and decrypt a message from PB-31 that reads: “Torpedo attack at 0232, October 28, in position 12-33N, 134-19E.” [1]

4 November 1943:
The convoy arrives at Saiki at 1200.

5 November 1943:
Departs Saiki and later arrives at Kure.

7 November 1943:
Departs Kure and later that day arrives at Innoshima. Drydocked.

13 November 1943:
Undocked and departs Innoshima and later arrives at Kure.

15 November 1943:
Departs Kure and later that day arrives at Saiki.

17 November 1943:
At 0700, PB-31 departs Saiki for Palau with auxiliary subchasers AOI MARU and TOKUHO MARU No. 10 escorting convoy No. 708 consisting of YAMAZURU MARU towing a tokugata unkato midget supply submarine and TOYOKAWA, ALASKA, PACIFIC, TAIKO, KAYO, KIBI and TAIEI MARUs.

26 November 1943:
At 1338, convoy No. 708 arrives at Palau.

30 November 1943:
At 0700, PB-31 departs Palau for Saiki escorting convoy No. FU-008 consisting of IKOMA, MAYA, HAVRE, SHINRYU, YASUKUNI, TESHIO, HOZUGAWA MARUs and DAIGEN MARU No. 3.

4 December 1943:
At 1640 high seas force TESHIO MARU to detach for Manila.

9 December 1943:
Auxiliary subchaser TAKUNAN MARU No. 8 joins the escort.

11 December 1943:
At 0100, arrives at Saiki.

21 December 1943:
At 0600, PB-31 departs Saiki for Palau with auxiliary minesweeper TAMA MARU and auxiliary subchaser TAMA MARU No. 6 escorting convoy No. O-106 consisting of IKOMA, YASUKUNI, UYO, NICHIAI, CHIBURI and KOSEI MARUs.

Bungo Straits. At 1134, LtCdr Robert E. M. Ward‘s USS SAILFISH (SS-192) torpedoes and sinks UYO MARU. Aboard UYO MARU were 950 men of the 202nd Naval Construction Unit. 192 of those men are killed. The escorts counter-attack, dropping 40 depth charges that slightly damage USS SAILFISH. The convoy returns to Saeki at about 2200 that same day.

23 December 1943:
At 0600, the convoy now renamed O-305 again sails from Saiki.

31 December 1943:
At 1730, arrives at Palau. Auxiliary minesweeper TAMAZONO MARU No. 3 and auxiliary submarine chaser CHa-32 join the convoy immediately prior to arrival.

5 January 1944:
At 0740, PB-31 departs Palau for Saiki with auxiliary subchaser CHa-32 escorting convoy No. FU-502 (sometimes called FU-503) consisting of TEIYU and SHOHO MARUs. At 2000, auxiliary subchaser CHa-32 is detached to return to Palau.

13 January 1944:
At 1330, auxiliary minesweeper TAMA MARU No. 6 joins the escort.

14 January 1944:
At 0520 arrives at Saiki.

15 January 1944:
At 0005 departs Saiki and at 0900 arrives at Kure.

23 January 1944:
At 0830 departs Kure and at 1540 arrives at Saiki.

24 January 1944:
At 0830 departs Saiki.

25 January 1944:
Arrives at Fukajima and departs at 1010 and at 1445 arrives at Saiki.

27 January 1944:
At 2300 departs Saiki.

28 January 1944:
At 0845 arrives at Moji.

31 January 1944:
At 0920, PB-31 departs Moji for Takao with auxiliary minesweeper TAKUNAN MARU No. 3 escorting convoy No. 133 consisting of tankers TAKETSU (BUTSU), SANKO (YAMAKO), NITTETSU and SHINCHO MARUs and YOZAN, SHOHO, CLYDE, OSAKA, MATSUEI (SHOEI) (1877 gt), ASAHISAN, YAMAGATA, SORACHI, FUKKO, SHINYU, and TOYO MARUs and DAIGEN MARU No. 3.

6 February 1944:
At 1500, arrives safely at Takao.

8 February 1944:
At 1100, departs Takao together with auxiliary minesweeper TAKUNAN MARU No. 3 escorting convoy TAPA-01 consisting of CLYDE, ASAHISAN, OSAKA and MATSUEI (SHOEI) (1877 gt) MARUs and DAIGEN MARU No. 3. The convoy sails at 9 knots.

9 February 1944:
TAKUNAN MARU No. 3 is detached from the convoy.

E 14 February 1944:
Minesweeper W-18 meets up with the convoy.

16 February 1944:
At 0845, arrives at Palau.

18 February 1944:
At 1100, PB-31 and W-18 join convoy PATA-02 that departed Palau for Takao consisting of KANKYO, MAKASSAR, MEXICO, SHOUN and two unidentified ships also escorted by two unidentified warships.

20 February 1944:
At 1100 PB-31 arrives back at Palau.

27 February 1944:
At 0550 PB-31 departs Palau alone and later joins up with destroyer HARUKAZE and torpedo boat SAGI escorting convoy TAPA-02 consisting of UCHIDE, NANREI and TESHIO MARUs that departed Takao on 20 February (DAIKEI and TOSHIN MARUs having being sunk en route).

29 February 1944:
120 miles W of Palau, LtCdr Phillip W. Garnett’s USS SARGO (SS-188) attacks the convoy and damages UCHIDE MARU at 08-57N, 132-52E.

1 March 1944:
UCHIDE MARU is abandoned. Her crew transfers to PB-31 and torpedo boat SAGI. The next day, UCHIDE MARU sinks.

4 March 1944:
At 1100 arrives at Palau.

6 March 1944:
At 0800, PB-31 departs Palau for Takao, Formosa with destroyers SHIGURE and SHIRANUHI and subchasers CH-38 and CH-37 escorting convoy PATA-04 consisting of TASMANIA, KENNICHI, BRAZIL, HINODE, ASAHISAN, KENZAN, YOZAN, CHINZEI and CLYDE MARUs. Torpedo boat SAGI joins the escort at an unknown point enroute.

13 March 1944:
At 1000, arrives at Takao.

17 March 1944:
At 1700 departs Takao escorting KASHII MARU to join convoy HI-48.

19 March 1944:
At 0900 arrives back at Takao.

20 March 1944:
At 0900 departs Takao with destroyer WAKATAKE and minelayer MAESHIMA escorting convoy combined convoys NISHI MATSU No.2/TAPA-06 consisting of MATSUE, CHUYO and HAMBURG MARUs.

26 March 1944:
At 0740 patrol boat PB-36 joins as an additional escort. In the afternoon during a violent rain squall, LtCdr Charles F. Brindupke's USS TULLIBEE (SS-284) attacks the convoy. The escorts attack without success, then sweep the seas with machine gun fire. To their surprise, a large explosion is heard. Later, a single survivor is rescued by WAKATAKE. [2]

27 March 1944:
At 1500 the convoy arrives at Palau.

30-31 March 1944: American Operation “Desecrate One”:
Palau. The anchorage is attacked by F6F "Hellcats", SBD "Dauntless", TBF "Avenger" and SB2C "Helldiver" carrier aircraft of Task Group 58. 1's USS ENTERPRISE (CV-6), USS BELLEAU WOOD (CVL-24) and USS COWPENS (CVL-25), TG 58. 2's USS BUNKER HILL (CV-17), USS HORNET (CV-12), USS MONTEREY (CV-26) and USS CABOT (CVL-28) and TG 58. 3's USS YORKTOWN (CV-10), USS LEXINGTON (CV-16), USS PRINCETON (CVL-23) and USS LANGLEY (CVL-27). TF 58’s planes attack many ships.

As the attack commences, convoy PATA-07 which formed up at 0500 and is leaving the atoll anchorages is dissolved. This convoy consisted of GOSHU, RAIZAN, KIBI (1941 built), TESHIO, HOKUTAI and RYUKO MARUs and tanker AKEBONO MARU escorted by PB-31, destroyer WAKATAKE and auxiliary subchaser CHa-26. All of these merchant ships were sunk over the following two days. Aircraft from USS ENTERPRISE and USS YORKTOWN sink PB-31 five miles SW of Kossol Passage at 07-30N, 134-30E.

10 May 1944:
Removed from the Navy List.

Author's Notes:
[1] According to COMSUBPAC's SORG Report, the attack was conducted by LtCdr Frank T. Watkins' USS FLYING FISH (SS-229) that sank coastal oiler KORYO MARU at about 0200 in the Philippine Sea at 12-02N, 137-28E.

[2] The Japanese claim a sinking, although USS TULLIBEE is now believed to have been sunk by one of its own torpedoes that made a circular run.

[3] No data were found detailing PB-31's movements during April 1940-May 1943. Readers with access to such data are requested to post the information on the Discussion and Questions board or's IJN Ship Message Board

[4] Convoy FU-607's maru names are according to research by Peter Cundall and Erich Muehlthaler. JUISSEI MARU is commonly shown in most Western texts as HOSHI MARU No.11.

Thanks go to the late John Whitman of Virginia, USA for info on CNO intercepts of Japanese messages; Gilbert Casse of France and Gengoro Toda of Japan.

-Bob Hackett, Sander Kingsepp and Peter Cundall

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