SHOKAITEI!

(MOMI-class)

IJN Patrol Boat No. 31:
Tabular Record of Movement

© 2007-2018 Bob Hackett, Sander Kingsepp, Berend van der Wal and Peter Cundall
Revision 9


1917:
A MOMI-class destroyer is ordered from Kawasaki Heavy Industies Ltd.

24 May 1919:
The destroyer is designated KIKU.

1920:
Kobe. Laid down.

10 September 1920:
Her call sign is GQXB.

13 October 1920:
Launched.

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.

18 October 1933:
Her call sign changes to JZEA.

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.

11 June 1940:
Her call sign changes to JZCA.

1 August 1940:
Attached to the Saeki Defense Forces and based at Kure.

15 November 1940:
Attached to the Kure Defense Forces Kure Guard unit Saeki Defense unit.

1 December 1941:
Her call sign changes to JJCQ.

2 ~ 7 December 1941:
Reclassified a minelayer patrol boat.

8 December 1941:
Departs Saeki on a mine laying mission. Lays type 92 mines in the diection of Shimonoseki.

14 December 1941:
At 1130, anti submarine sweeping in Iyo Nada.

15 December 1941:
Begins an anti submarine sweep in Iyo Nada.

16 December 1941:
Arrives at Saeki.

17 December 1941:
Departs Saeki on anti submarine sweeping mission in Iyo Nada.

21 December 1941:
Arrives Saeki.

22 December 1941:
Departs Saeki on anti submarine sweeping mission in Iyo Nada.

21 December 1941:
Arrives Saeki.

25 December 1941:
Departs Saeki on anti submarine sweeping mission in Iyo Nada.

30 December 1941:
Arrives Saeki.

1 January 1942:
Departs Saeki on a patrol. Arrives off the coast of Mitajiri later that day.

2 January 1942:
Departs off the coast of Mitajiri on a patrol and returns later this day.

3 January 1942:
Departs off the coast of Mitajiri on a patrol. Arrives at Saeki later this day.

7 January 1942:
Departs Saeki on a patrol. Arrives at Fukuura later that day.

8 January 1942:
Departs Fuukura on a patrol. Arrives at Sukumo later this day.

9 January 1942:
Departs Sukumo on a patrol.

10 January 1942:
Arrives at Sukump.

12 January 1942:
Departs Sukumo on a patrol. Arrives at Fukuura later that day.

13 January 1942:
Arrives at Saeki.

14 January 1942:
Anchors.

18 January 1942:
Departs Saeki on a patrol.

19 January 1942:
Arrives at Sukumo.

20 January 1942:
Departs Sukumo on a patrol.

22 January 1942:
Arrives at Saeki.

24 January 1942:
Departs Saeki on a patrol.

25 January 1942:
Arrives at Sukumo.

27 January 1942:
Departs Sukumo on a patrol.

28 January 1942:
Arrives at Saeki.

30 January 1942:
Departs Saeki on a patrol.

31 January 1942:
Arrives at Sukumo.

2 February 1942:
Departs Sukumo on a patrol.

3 February 1942:
Arrives at Saeki.

5 February 1942:
Departs Saeki on a patrol.

6 February 1942:
Arrives at Sukumo.

7 February 1942:
Departs Sukumo and arrives at Saeki later this day.

8 February 1942:
Departs Saeki on a patrol and arrives at Sukumo later that day.

9 February 1942:
Departs Sukumo on a patrol and arrives back at Sukumo later this day.

10 February 1942:
Departs Sukumo on a patrol and arrives back at Sukumo later this day.

11 February 1942:
Departs Sukumo and arrives at Saeki later this day.

14 February 1942:
Departs Saeki on a patrol.

15 February 1942:
Arrives at Saeki.

18 February 1942:
Departs Saeki on a patrol.

19 February 1942:
Arrives at Saeki.

22 February 1942:
Departs Saeki on a patrol.

23 February 1942:
Arrives at Kitsuki.

24 February 1942:
Departs Kitsuki on a shooting excercise.

25 February 1942:
Arrives back at Kitsuki.

26 February 1942:
Departs Kitsuki on a towing excercise and arrives at Saeki later that day.

27 February 1942:
Anchors.

28 February 1942:
Departs Saeki and arrives at Kure later this day.

4 March 1942:
Auxiliary boiler running trials.

17 March 1942:
Auxiliary boiler running trials.

19 March 1942:
Departs Saeki on a patrol.

20 March 1942:
Arrives at Uratsu. Departs later that day on a patrol.

21 March 1942:
Arrives at Suzaki.

22 March 1942:
Departs Suzaki and arrives at Saeki later this day.

26 March 1942:
Departs Saeki on a machine gun shooting excercise and arrives at Kitsuki kater that day.

27 March 1942:
Departs Kitsuki on an excercise and arrives at Saeki later this day.

29 March 1942:
Departs Saeki on a patrol and arrives at Sukumo later that day.

1 April 1942:
Departs Sukumo on a combined minesweeping excercise and patrol. Arrives back at Sukumo later this day.

2 April 1942:
Departs Sukumo and arrives at Saeki later that day.

4 April 1942:
Departs Saeki on a patol and arrives at Sukumo later this day.

5 April 1942:
Departs Sukumo and arrives at Saeki later that day.

7 April 1942:
Departs Saeki on a patrol.

8 April 1942:
Arrives at Sukumo.

9 April 1942:
Departs Sukumo and arrives at Saeki later this day.

10 April 1942:
Departs Saeki on a patrol and arrives off Nagoya later that day.

11 April 1942:
Anti submarine sweeping off the coast of Nagoya.

13 April 1942:
Arrives at Tanabe.

14 April 1942:
Departs Tanabe on a combined anti submarine sweep and patrol.

16 April 1942:
Arrives at Sukumo.

18 April 1942:
Departs Sukumo an a patrol.

20 April 1942:
Auxiliary cruiser BANGKOK MARU receives the order to rendezvous with the Soviet 4,761-ton cargo steamer ANGARSTROI (ex-GRANTLEY HALL), en route to Kushimoto for inspection, carrying a boarding party from PB-31.

21 April 1942:
In heavy seas and limited visibility BANGKOK MARU misses the rendezvous point and proceeds directly to Kushimoto.

22 April 1942:
BANGKOK MARU arrives at Kushimoto. Inspects ANGARSTROI and another Soviet steamer, the 2,363-ton timber carrier VANZETTI, detained around the same time. Meanwhile PB-31 arrives at Saeki.

28 April 1942:
Departs Saeki on a patrol.

30 April 1942:
Arrives at the Bungo Strait.

1 May 1942:
Departs the Bungo Strait on a patrol and arrives at Saeki later this day.

3 May 1942:
Departs Saeki on a patrol.

4 May 1942:
Arrives at Sukumo.

5 May 1942:
Departs Sukumo on a patrol.

6 May 1942:
Arrives at Sukumo.

8 May 1942:
Departs Sukumo on a minesweeping exercise and arrives back at Sukumo later that day.

9 May 1942:
Departs Sukumo on a sweeping mission.

10 May 1942:
Arrives at Saeki.

15 May 1942:
Departs Saeki on a gunfire practice and sweeping excercise.

16 May 1942:
Arrives at Sukumo. Departs later this day on a shooting and sweeping excercise.

17 May 1942:
Arrives at Saeki.

19 May 1942:
Departs Saeki on a shooting and sweeping excercise.

20 May 1942:
Arrives at Sukumo.

21 May 1942:
Departs Sukumo on a shooting and sweeping excercise.

22 May 1942:
Arrives at Sukumo.

23 May 1942:
Departs Sukumo on a shooting and sweeping excercise.

24 May 1942:
Arrives at Saeki.

27 May 1942:
Departs Saeki and arrives at Beppu later this day.

28 May 1942:
Departs Beppu escorting aircraft carrier UNYO during her trial runs. Arrives at Tokuyama later that day.

29 May 1942:
Departs Tokuyama on a sweeping mission.

31 May 1942:
Arrives at Saeki.

3 June 1942:
Departs Saeki on a rescue mission for auxiliary patrol boat SHUNZEI MARU NO. 5. SHUNZEI MARU No. 5 sank after being shelled by Lt.Cdr. Stanley P. Moseley’s USS submarine POLLACK (SS-180) on 31 May 1942.

6 June 1942:
Arrives at Saeki.

9 June 1942:
Departs Saeki on a patrol in the Bungo Strait.

13 June 1942:
Arrives at Saeki.

14 June 1942:
Departs Saeki and arrives at Kure later this day. Departs later that day.

15 June 1944:
Arrives at Saeki.

19 June 1942:
Departs Saeki on a patrol in the Bungo Strait.

25 June 1942:
Arrives at Saeki.

27 June 1942:
Departs Saeki on a patrol in the Bungo Strait and arrives back at Saeki later this day.

29 June 1942:
Departs Saeki to meet up with and escort fast speed (14 knots) convoy ‘D ‘ bound for Kure consisting of KANSAI, KINUGAWA, NAKO, TAIFUKU and KIYOSUMI MARUs escorted by destroyer NAGATSUKI and torpedo boat HATSUKARI. Patrol boat PB-46 aslo arrives and joins the escort. Convoy ‘ D’ departed Manila on 26 May 1942.

30 June 1942:
Around 1400 convoy ‘D’ passes point E (29-00N, 132-00E).

1 July 1942:
Arrives at Saeki.

5 July 1942:
Departs Saeki to meet up with and escort fast speed (13 knots) convoy ‘E' bound for Ujina consisting of SHOHO, YAMAZUKI, YAMAZATO, ASAKASAN, BUENOS AIRES, HIROKAWA, SADO and SAGAMI MARUs escorted by destroyer MINAZUKI. PB-46 also arrives and joins the escort. Convoy ‘E’ departed Manila on 2 July 1942.

6 July 1942:
Convoy ‘E’ passes point E (29-00N, 132-00E).

7 July 1942:
Arrives at Saeki.

10 July 1942:
Departs Saeki and arrives at Kure later that day.

13 July 1942:
Arrives at Agenosho.

14 July 1942:
Departs Agenosho and arrives at Kure later this day.

1 ~ 8 August 1942:
Departs Kure.

9 August 1942:
Arrives at Saeki.

10 Auguat 1942:
Departs Saeki on an anti submarine sweep.

12 August 1942:
Arrives at Saeki.

14 Auguat 1942:
Departs Saeki on an anti submarine sweep.

15 August 1942:
Arrives at Saeki.

18 Auguat 1942:
Departs Saeki on an anti submarine sweep and arrives back at Saeki later that day.

19 Auguat 1942:
Departs Saeki on an anti submarine sweep.

21 August 1942:
Arrives at Saeki.

22 August 1942:
Departs Saeki to meet up with and escort auxiliary transport NOSHIRO MARU bound for Kure.

23 August 1942:
Arrives at Saeki.

24 August 1942:
Departs Saeki to take part in an Y equipment experiment and arrives back at Saeki later this day.

29 August 1942:
Departs Saeki on a patrol at the Bungo Strait.

30 August 1942:
Arrives at Saeki.

1 September 1942:
Departs Saeki.

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

E 6 September 1942:
The escorts are detached.

8 September 1942:
Departs Saeki on a transport mission.

13 September 1943:
Arrives at Saeki.

14 September 1942:
Departs Saeki to act as a warning ship off the coast of Oita and to cooperate with the training of the Second Air Squadron.

19 September 1942:
Arrives at Oita.

20 September 1942:
Departs Saeki.

21 September 1942:
Arrives at Saeki.

22 September 1942:
Departs Saeki.

26 September 1942:
Arrives at Saeki.

29 September 1942:
Departs Saeki to meet up with and escort Oki transport convoy No. 1 echelon 4, bound for Rabaul, consisting of CHOKO, HAMBURG and IKUSHIMA MARUs escorted by destroyers HATAKAZE and MINEKAZE and torpedo boat HATO.

6 October 1942:
Arrives at Saipan, Marianas and detaches.

8 October 1942:
Departs Saipan.

12 October 1942:
Arrives at Saeki.

17 October 1942:
At 0500 HOLLAND MARU sank by an enemy submarine (USS TRIGGER (SS-237)) 10 nautical miles off the coast of Oshima. Departs Saeki on an anti submarine sweep of this area. PB-46 also arrives to hunt for the enemy submarine.

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.

20 October 1942:
Anti submarine sweeping at the Fukushima area.

21 October 1942:
Arrives at Saeki.

24 October 1942:
Departs Saeki with auxiliary cruiser SAIGON MARU to assist with the rescue operation of the auxiliary oiler NISSHO MARU. Submarine tender CHOGEI, minelayer NASAMI and subchaser CH-36 are also sent to take part in the rescue operation.

25 October 1942:
CHOGEI starts towing NISSHO MARU. PB-31 continues to escort and act in lifesaving capacity.

26 October 1942:
Arrives at Saeki. Departs later that day with torpedoboat HATO escorting IJA landing craft depot ship AKITSU MARU.

27 October 1942:
Arrives at Saeki. Loads type 95 depth charges.

28 October 1942:
Departs Osaka.

29 October 1942:
Arrives at Osaka.

30 October 1942:
Departs Osaka escorting a convoy.

2 November 1942:
Arrives at Yokosuka.

10 November 1942:
Departs Yokosuka on a Radar test and arrives at Tateyama later this day.

11 November 1942:
Departs Tateyama on a Radar test and arrives back at Tateyama later that day.

12 November 1942:
Departs Tateyama on Radar test and arrives back at Tateyama later this day.

15 November 1942:
Departs Yokosuka escorting East Convoy No. 11 consisting of two unidentified ships.

17 November 1942:
Arrives at Yuranai and departs later that day still on the escort mission. Arrives at Kobe later that day.

19 November 1942:
Departs Kobe.

20 November 1942:
Arrives at Saeki.

22 November 1942:
Arrives at Sukumo. At 1200 leaves for second deployment patrol. Various ships are transiting the Bingo Suido. At 1530 light cruiser AGANO and subchaser unit No.17 are due at southern tip of eastern channel from Truk. Meanwhile from night before torpedo boats HATO and MANAZURU and minelayer NASAMI together with PB-31 patrol patrol areas F3, J2, K1 and E2 respectively. Later that day PB-31 undertakes minesweeping near the seventh buoy of the east channel.

23 November 1942:
Departs Sukumo on an anti submarine sweep and arrives at Furue later this day. Departs Furue on a patrol later that day. At 0830 begins escorting Landing craft depot ship AKITSU MARU with destroyers ARASHI and NOWAKI (bound from Kure to Truk). Then joins with minelayers NUWAJIMA and NASAMI and torpedo boat MANAZURU and patrols patrol areas (PB-31) D0 (NUWAJIMA), E2 (NASAMI) and EI (MANAZURU).

24 November 1942:
Arrives at Saeki.

2 December 1942:
Departs Saeki with minelayer NUWAJIMA escorting the "E" convoy (No. 8 Military Movement) consisting of BANDOENG, CHIFUKU, SUMATRA and NICHIRYU MARUs.

3 December 1942:
About 1 hour after sunset, at 28 degrees north ends the escort and heads towards auxiliary transport NOSHIRO MARU.

4 December 1942:
Around sunset meets up with IJN auxiliary transport NOSHIRO MARU and starts escorting her.

5 December 1942:
Arrives at Saeki.

6 December 1942:
Anchors.

7 December 1942:
Departs Saeki with minelayer YURIJIMA escorting "F" convoy (No. 8 Military Movement) consisting of SHINSEI MARU No.17, KENZAN, FUKOKU, SHIRAHA, AKAGISAN MARUs.

9 December 1942:
The escorts are detached at 27N. Arrives at Saeki later that day.

10 December 1942:
Anchors.

11 December 1942:
Departs Saeki.

12 December 1942:
Meets up with and starts escorting IJN auxilary transports NOSHIRO MARU and TOA MARU NO. 2 GO bound for Rabaul sailing at 11.5 knots.

E 13 December 1942:
At 29N, detaches.

14 December 1942:
Arrives at Saeki.

16 December 1942:
Departs Saeki. At 2020 torpedo boat HATO detects an enemy submarine 147 degrees 56 Ri off Okinoshima and lauches an attack.

17 December 1942:
At 0755, joins torpedoboat HATO and takes the first position in the anti submarine sweeping formation. PB-31 then submarine chaser CH-37 takes second position and minelayer NUWAJIMA takes third position. Later PB-46 takes over from NUWAJIMA. PB-36 arrives and assumes command in first position, relieving HATO.

19 December 1942:
At first light at 0900 the sweep ends. PB-31 and PB-46 begin patrolling the E1, E2, J1 and J2 patrol zones.

20 December 1942:
At 1730 the ship is relieved by minelayer NUWAJIMA, PB-36 and submarine chaser CH-37. Arrives at Saeki.

21 December 1942:
Departs Saeki on an anti submarine sweep.

22 December 1942:
Arrives with torpedoboat HATO at Saeki.

24 December 1942:
Departs Saeki on an escort mission.

26 December 1942:
Arrives at Saeki.

28 December 1942:
Departs Saeki.

28 December 1942:
Arrives at Agenosho.

29 December 1942:
Departs Agenosho and arrives at Kure later this day.

31 December 1942:
Departs Kure and arrives at Saeki later that day.

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 0255 begins an anti submarine sweep. 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. At 0700, at 166 degrees and 57 nautical miles of the Okinoshima lighthouse joins minelayer NASAMI and takes the first position in the sweeping formation. At 0840, cable-minelayer TSURUSHIMA detaches. At 1125, PB-36 is congruent. At 1132 minelayer NATSUSHIMA joins. At 1220, takes the first position in the sweeping formation followed by NATSUSHIMA, NASAMI and PB-36. At 1415, cable-minelayer TSURUSHIMA rejoins the sweeping formation. At 1949, cable-minelayer TSURUSHIMA drops depth charges. At 2035, cable-minelayer TSURUSHIMA detaches. At 2115, torpedoed at 176 degrees and 59 nautical miles of the Ogijima lighthouse. At 2117, drops 8 type 95 depthcharges.

7 January 1943:
At 0130, minelayers NASAMI and NATSUSHIMA detach. At 1130, heads toward Fukuura for resupplying. Arrives at Fuukura later that day and is resupplied by cable-minelayer TSURUSHIMA. Thereafter departs Fukuura. At 2135 starts searching for the enemy with her listening device.

8 January 1943:
At 0155, discovers an enemy submarine at 170 degrees and 53 nautical miles off the Okinoshima lighthouse. At 0200, drops 10 type 95 depthcharges. At 0234 discovers an enemy submarine. At 0236, drops 8 type 95 dethcharges. At 0304, discovers an enemy submarine. At 0306, drops 5 type 95 depthcharges. At 1015, cable-minelayer TSURUSHIMA joins the sweep. At 1625, minelayer NASAMI joins the sweep. At 1800, PB-31 takes the first position in the sweeping formation followed by the NASAMI and TSURUSHIMA.

9 January 1943:
Arrives at Sukumo. Departs later this day and arrives at Saeki later that day.

10 January 1943:
Anchors.

11 January 1943:
Departs Saeki, meets up with and starts escorting MIIKE MARU.

13 January 1943:
Arrives at Saeki.

14 January 1943:
Departs Saeki.

17 January 1943:
Departs Saeki with subchaser CH-36 escorting convoy "U" consisting of YAMATO, MEIKAI, MOMOHA, INDUS, NAGANO and KIRIHA MARUs.

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

21 January 1943:
Departs Saeki. At an unknown point meets up with IJN auxilary transport KUNISHIMA MARU bound for Truk and starts ecorting her.

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. Detaches at an unknown point and heads towards IJA landing craft depot schip MAYASAN MARU bound for Ujina. Unable however to find the MAYASAN MARU.

23 January 1943:
Arrives at Saeki.

24 January 1943:
Anchors.

3 February 1943:
Departs Saiki and patrols the Bungo Suido. Arrives at Kure later that day.

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.

28 February 1943:
Escorts MIIKE MARU. Minelayer YURIJIMA joins the escort.

1 March 1943:
Arrives at Saeki.

4 March 1943:
Arrives at Kure escorting auxiliary submarine tender YASUKUNI MARU. Departs later this day and arrives at Saeki later that day.

5 March 1943:
Departs Saeki.

6 March 1943:
Arrives at Sukumo and departs later this day.

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.

9 March 1943:
Unable to find auxilairy repairship YAMASHIMO MARU bound for Yokohama.

11 March 1943:
PB-46, PB-31 (from Sukumo), 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.

16 March 1943:
Arrives at Saeki.

17 March 1943:
Departs Saeki with minelayer YURIJIMA escorting the Military Movement No. 8’s convoy "H2" consisting of NIKKI, HANKOW and MEIZAN MARUs.

18 March 1943:
At 29N, with YURIJIMA detaches. Switches to patrolling the southern entrance to the Bungo Suido.

20 March 1943:
Arrives at Saeki.

23 March 1943:
Arrives at Kure.

27 March 1943:
Departs Saeki with minelayer NASAMI and auxiliary minesweeper TAKUNAN MARU No. 3 escorting the Military Movement No. 8’s convoy “J2” consisting of KACHOSAN, JINZAN, KOSO, SHICHISEI and UGO MARUs.

E 28 March 1943:
At 29N, with NASAMI and TAKUNAN MARU No. 3 detaches.

29 March 1943:
At 1200 neets up with Navy oiler ASHIZURI and escorts the ship north to Fukajima, where PB-31 is detached.

1 April 1943:
Departs Saiki with CH-36 and minelayer NUWAJIMA and joins destroyers AKIKAZE and URAKAZE heading north.

2 April 1943:
Arrives back at Saiki.

3 April 1943:
The escorts are detached off Fukajima and arrive back at Saiki. Later that day departs Saeki with subchaser CH-36 and auxiliary minesweeper TAKUNAN MARU No. 3 escorting the Military Movement No. 8‘s convoy ‘L2’ of HEIAN, HOFUKU, KONAN, MYOGI and YUBAE MARUs and SHINSEI MARU No. 17.

4 April 1943:
At 29N, at 1800 with CH-36 and TAKUNAN MARU No. 3 detaches. Arrives at Saeki later this day.

5 April 1943:
Arrives back at Saiki. Departs Saeki.

6 April 1943:
At 27-17N, 130-42 meets up with landing depot schip AKITSU MARU and escorts her north.

7 April 1943:
Off Fukajima detaches and arrives at Saeki later this day.

9 April 1943:
Departs Saiki on an anti submarine patrol.

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 on an anti submarine patrol.

17 April 1943:
Meets cruiser OYODO. Arrives back at Saiki.

19 April 1943:
Departs Saiki and escorts Army landing craft depot ship NIGITSU MARU heading south.

20 April 1943:
Departs Saeki.

21 April 1943:
At 2100, at 230 degrees and 30 minutes north and 132 degrees and 30 minutes east off Muroto Zaki meets up with auxiliary cruiser KIYOSUMI MARU and starts escorting her.

22 April 1943:
East of Tanega Shima detaches and later arrives back at Saiki.

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

21 May 1943:
Undocked.

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.

5 June 1943:
Arrives at Palau.

7 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.

8 June 1943:
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. PB-31 takes her survivors on board. 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.

14 June 1943:
Arrives at Saeki.

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

23 June 1943:
Arrives back at Saiki.

25 June 1943:
At 0800, PB-31 and minesweeper W-31 depart Saeki escorting convoy O-503 consisting of NICHIZUI, TATSUMIYA and HAVRE MARUs. The ships sail at 9 knots.

2 July 1943:
Arrives at Palau.

6 July 1943:
Departs Palau.

8 July 1943:
Returns to Palau.

11 July 1943:
Departs Palau and meets up with and joins the escort of incoming convoy O-404 consisting of HOZUKAWA, KAYO, MEXICO and TAIKO MARUs escorted by minesweepers W-17 and W-18. The convoy carries troops and equipment of the 51st Army Division.

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 YURIJIMA and auxiliary minesweeper TAKUNAN MARU No. 3 escorting convoy No. O-003 consisting of TAISHO, TOYOKAWA and DELAGOA MARUs. At latitude 29N, YURIJIMA and TAKUNAN MARU No. 3 are detached to return to Saiki.

8 August 1943:
Arrives at Palau.

12 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.

27 September 1943:
The convoy arrives off Fukajima and is dissolved.

28 September 1943:
Arrives at Saeki.

29 ~ 30 September 1943:
Departs Saeki for Kure.

9 October 1943:
Departs Kure escorting convoy O-905 consisting of TAISHO, KURAMASAN, NAPLES, TOSHO and SAIHO MARUs. At 1130, the convoy returns to Kure.

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:
At Fuka Jima ends the escort. Arrives at Saeki later this day. 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 O-708 consisting of YAMAZURU MARU towing a tokugata unkato midget supply submarine and TOYOKAWA, ALASKA, PACIFIC, TAIKO, KAYO, KIBI and TAIEI MARUs.

21 November 1943:
At 1550, at 21.17N-136.30E a fire breaks out in the rear boiler room of TAIKO MARU. Around 1830 the whole ship is on fire. The crew abondes the ship. KIBI MARU starts towing her. Provides assistance and escorts the two ships. At 1905 TAIKO MARU sinks. PB-31 escorts KIBI MARU back to the convoy.

26 November 1943:
At 1338, convoy O-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. At 2400 the convoy loses sight of the TESHIO MARU.

5 December 1943:
At 0630 the convoy reverses it course in order to seach for the TESHIO MARU. At 0800 PB-31 reports that the TESHIO MARU cann’t be found.

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

10 December 1943:
At 2130 passes Fuka Jima. At 2155, ends the escort and detaches. At 2200 heads towards Saeki.

11 December 1943:
At 0100, arrives at Saiki.

12 December 1943:
Loads heavy oil.

18 December 1943:
Loads heavy oil.

20 December 1943:
Loads various goods.

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. At 1413, detaches and heads towards Fukujima. Arrives there later that day and departs again at 1830. Later this day arrives at 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 1530 arrives at the Nishi (northwest passage) channel entrance, Ngarchelong, Palau. 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.

6 January 1944:
At 0825, TEIYU MARU falls behind because of a mechanical problem. At 0855, her mechanical problem is solved and she rejoins the convoy.

11 January 1944:
At 0700, SHOHO MARU falls behind because of a mechanical problem. At 0715, her mechanical problem is solved and she rejoins the convoy. At 0840, TEIYU MARU falls behind because of a mechanical problem. At 0910, her mechanical problem is solved and she rejoins the convoy.

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

14 January 1944:
At 0230 arrives at Fukujima. At 0420 ends the escort and heads towards Saeki. At 0520 arrives at Saiki.

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

20 January 1944:
Loads food and drinks.

22 January 1944:
Loads heavy oil.

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

24 January 1944:
At 0830, departs Fukujima. At 0900, begins an anti submarine sweep.

25 January 1944:
Arrives at Fukajima and departs at 1010 and At 1020, the anti submarine sweep is cancelled. At 1150, arrives at Fukujima. Arrives at Saeki at 1445. Loads heavy oil.

27 January 1944:
At 2300 departs Saiki.

28 January 1944:
At 0845 arrives at Moji. Loads heavy oil.

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. Loads 130t heavy oil.

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.

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

16 February 1944:
At 0845, arrives at Palau. Loads 167t heavy oil.

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

19 February 1944:
At 1200, detaches and while returning to Palau carries out an anti submarine sweep.

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

25 February 1944:
Anchors.

27 February 1944:
At 0550 PB-31 departs Palau alone.

28 February 1944:
At 1503, 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.

E 5 March 1944:
Loads heavy oil and food.

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 and submarine chaser CH-6 join as additional escorts. 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.

29 March 1944:
Departs Palau. At 2000, returns because of the harbor departure postponement of convoy PATA-07. Anchors near the port entrance. At 2200, a PATA-07 convoy meeting takes place on the GOSHU MARU.

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 with several hits to the port side of the ship 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-November 1941. Readers with access to such data are requested to post the information on the Discussion and Questions board or j-aircraft.org'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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