Japanese Auxiliary Gunboats

KOKAI HOKAN!

(CHOJUSAN MARU, prewar)

IJN CHOJUSAN MARU:
Tabular Record of Movement

© 2020 Gilbert Casse, Berend van der Wal and Peter Cundall

1 August 1928:
Uraga. Laid down by Uraga Senkyo K.K. shipyard for Chosen Yusen K.K. as a 2,131-tons cargo ship.
27 November 1928:
Launched and named CHOJUSAN MARU.
28 February 1929:
Completed and registered at Jinsen, Chosen (now Inchon, South Korea) with a Gross Registered Tonnage (GRT) of 2,131-tons and a Net Registered Tonnage (NRT) of 1,239 tons. Her call sign is PHLC. [1]
1 December 1932:
Her call sign is changed to JRKB.
In service on the Hanshin, Busan (Fuzan), Chosen (now Pusan, South Korea), Chosen (now North Korea) E coast and Urajio (Vladivostok), Soviet Union route.
7 September 1937:
Requisitioned by the IJN.
11 September 1937:
Tama. Registered as an auxiliary gunboat attached to the Yokosuka Naval district under instruction No. 594. Navy Capt Miyamoto Sadachika (39) is appointed CO. Conversion to military duty begins at Tama K.K. shipyard.
17 September 1937:
Attached to the First Gunboat Division under instruction No. 604.
4 October 1937:
Conversion is completed.
5 October 1937:
Departs Tama.
6 October 1937:
Arrives at Kure.
9 October 1937:
Departs Kure and arrives at Sasebo. Departs later for Karatsu (Oshima).
20 October 1937:
Arrives at Karatsu. Departs later
29 October 1937:
Departs Sasebo.
8 November 1937:
Departs Wusong (Woosung), Shanghai, China and returns there later this day.
13 November 1937:
Departs Wusong.
18 November 1937:
Departs Xu Pukou, China.
1 December 1937:
Attached to Vice Admiral (later Admiral) Hasegawa Kiyoshi’s (31) Third Fleet, First Gunboat Division.
6 December 1937:
Arrives at Kirun, Formosa (now Keelung, Taiwan).
7 December 1937:
Departs Kirun.
10 December 1937:
Arrives at Tong Ao Island, Wanshan Archipelago, China.
1025 ~ 1340: lies alongside light cruiser NAGARA. Departs Tong Ao Island later that day.
13 December 1937:
Arrives at Tong Ao Island.
At 1634, lies alongside to port of seaplane tender KAMOI.
1645 ~ 1725: loads boiler water. At 1755, separates from KAMOI . Departs Tong Ao Island later this day.
2 January 1938:
Arrives at Kirun.
6 January 1938:
Departs Kirun for southern China waters.
9 January 1938:
Arrives at Kirun.
1 February 1938:
Attached to Vice Admiral (later Admiral) Shiozawa Koichi’s (32) Fifth Fleet, First Gunboat Division.
11 February 1938:
Departs Kirun for Kinmen (Quemoy) Island, China.
19 March 1938:
Departs Kinmen Island.
20 March 1938:
Arrives at Mako, Pescadores.
20 March ~ 5 April 1938:
In drydock.
6 April 1938:
Departs Mako.
4 May 1938:
Departs Kinmen Island.
15 May 1938:
Anchors in Amoy (Xiamen) inner harbor, China.
17 May 1938:
Anchors at Amoy.
23 May 1938:
Departs Amoy.
2 June 1938:
Arrives at Mako.
5 June 1938:
Departs Mako.
6 June 1938:
Arrives at Amoy. Departs later.
26 June 1938:
Arrives at Mako.
29 June 1938:
Departs Mako.
30 June 1938:
Arrives at Nanao Island, China and subsequently anchors.
1 July 1938:
Departs Nanao Island.
7 July 1938:
Arrives at Mako. Departs there later this day.
10 July 1938:
Arrives at Foochow (now Fuzhou), China. Departs later.
20 July 1938:
Arrives at Nanao Island. Departs there and arrives at Hou Ao, China later that same day.
22 July 1938:
Anchors twice.
26 July 1938:
Departs Hou Ao.
13 August 1938:
Arrives at Mako.
15 August 1938:
Departs Mako for southern China waters.
31 August 1938:
Arrives at Kirun.
4 September 1938:
Departs Kirun for southern China waters.
9 September 1938:
Arrives at Mako.
12 September 1938:
Departs Mako for Nanao Island.
15 September 1938:
Attached to the First Gunboat Division under instruction No. 785.
5 October 1938:
Anchors.
5 ~ 15 October 1938:
Departs Nanao Island for Changshan berth, China.
15 October 1938:
Departs Changshan berth.
7 November 1938:
Departs Kirun.
10 November 1938:
Ship CO is missing.
12 November 1938:
Arrives at Kure.
13 November 1938:
Released from the First Gunboat Division under instruction No. 934.
29 November 1938:
Removed from the Navy’s list under instruction No. 990 and released to her owners.
20 November 1941:
Requisitioned again by the IJN.
10 December 1941:
Registered as an auxiliary gunboat attached to Sasebo Naval District. Navy (Resv) LtCdr Ito Toshihide is appointed CO.
12 December 1941:
Tama. Conversion to military duty begins at Tama K.K. shipyard.
25 December 1941:
Conversion is completed.
31 December 1941:
Tactically assigned to Mako Guard District.
E1 ~ 13 January 1942:
Arrives at Mako.
14 January 1942:
After conducting anti-submarine sweeping S Sabo (Three) Islets, Formosa (now Chamuyu Island, Taiwan) enters port.
15 January 1942:
Attached to Mako Base Defense Unit under Mako Guard Force Order No. 7.
28 January 1942:
CHOJUSAN MARU and minelayer HOKO (BOKO) took over escort of an Army transport convoy consisting of KITANO, TOYOHASHI, NAGATO, BENGAL, RYOGA, RYUYO MARUs and TAMON MARU No. 5.
1 February 1942:
Mako Guard District instruction No. 12:
1. Secret wireless message No. 995. IJA transport KOFUKU MARU departs Mako, on 2 Feb ‘42 at 0700 and passes through Nanpeng Islands, China to FC on the CAI route.
2. Minelayer HOKO and auxiliary gunboat CHOJUSAN MARUs take over the escort in the home area. Minelayer HOKO CO will be in command. Air Force should cooperate.
3 February 1942:
Arrives at Haiphong, French Indochina (now Vietnam).
17 February 1942:
Mako Guard District wireless instruction No. 18:
1. Auxiliary gunboats SENYO and CHOJUSAN MARUs and minelayer HOKO under command of SENYO MARU CO are escorts for IJA transport ship mentioned in secret message No. 680.
A. Minelayer HOKO escorts convoy No. 1 consisting of six vessels and 14 sections. Auxiliary gunboats SENYO and CHOJUSAN MARUs escort convoy No. 2 consisting of seven vessels and 10 sections.
B. Departure date and time: Convoy No. 1, 21 Feb ‘42 at 0800 and convoy No. 2, 23 Feb ‘42 at 0800.
C. Escort area: from Mako to FEF.
D. Route goes straight to FEF.
2. Air Force should cooperate with escorts.
E 17 ~ 20 February 1942:
Installation of shield board at Mako Navy Engineering Department.
20 February 1942:
Mako Guard Office instruction No 12:
As soon as ready depart Mako to assist small IJA transport SHUKI MARU drifting after mechanical failure at 23-45N, 120-00E.
Departs Mako on a rescue mission for IJA transport SHUKI MARU.
25 February 1942:
Departs Mako with auxiliary gunboat SENYO MARU escorting a convoy consisting of KINRYUZAN, TAISHO and HIBURI MARUs and six unidentified ships. Arrives at Takao, Formosa (now Kaoshiung, Taiwan) later this day due to HIBURI MARU ’s rudder failure. Departs later that day on escort mission, presumably escorting HIBURI MARU.
2 March 1942:
Arrives at Cam Ranh Bay, French Indochina (now Vinh Cam Ranh, Vietnam).
6 March 1942:
Departs Cam Ranh Bay.
12 March 1942:
Arrives at Mako.
20 March 1942:
Mako Guard Office instruction No 29:
1 Minelayer SOKUTEN and auxiliary gunboat CHOJUSAN MARU under command of Minelayer CO are escorts of IJA transports convoy.
A Convoy consists of: FUKKAI, KOCHI, RYUZAN, TAIKAI MARUs and YOSHIDA MARU No. 1 bound for Cam Ranh.
TETSUYO MARU bound for Bangkok.
MONTREAL, SAMARANG, PENANG and TEIKAI (ex-German FULDA) MARUs bound for Singapore.
B Departure date and time: 28 Mar ‘42 at 0800.
C Escort area: from Mako to Cam Ranh.
D Direct route to Cam Ranh, speed 9 knots.
E Other: set by CO.
This message is apparently in error as CHOHAKUSAN MARU, not CHOJUSAN MARU was the escort.
30 March 1942:
After returning to Mako, depart on 4 Apr ‘42 and enter Kirun drydock on 5 Apr ‘42 under Mako Security Instruction No. 377.
4 April 1942:
Departs Mako for Kirun.
5 ~ 22 April 1942:
Enters drydock at Kirun. Undergoes construction work for 200 items including left anchor storage on front deck.
10 April 1942:
Released from Mako Guard Unit under Mako Security Service instruction No. 27. Attached to Vice Admiral Takahashi Ibo’s (36) Southwestern Area Fleet, First Surface Escort Squadron. Rated as the 2nd Escort Unit.
22 April 1942:
Departs Kirun.
23 April 1942:
Arrives at Mako.
25 April 1942:
Scheduled to have one 9m cutter in storage at Yokosuka Navy Yard.
28 April 1942:
Released from Mako Guard Unit under Mako Security Service instruction No. 34.
8 May 1942:
Departs Mako escorting convoy No. 304 consisting of NOTO MARU and one unidentified merchant ships.
10 May 1942:
Arrived at Lingayen.
11 May 1942:
Departed Lingayen.
14 May 1942:
Arrives at Cape St. Jacques, French Indochina (now Vung Tau, Vietnam).
18 May 1942:
At 1400, departs Cape St. Jacques escorting convoy No. 403 consisting of IJA transport IIDA MARU and nine unidentified merchant ships.
25 May 1942:
At 1500, arrives at Mako.
June 1942:
Rated as Second Escort Squadron, 2nd Unit.
1 June 1942:
At 1200, departs Mako escorting convoy No. 310 consisting of Government requisitioned YULIN MARU (ex-Norwegian HERLEIK) and one unidentified merchant ship.
4 June 1942:
YULIN MARU (ex-Norwegian HERLEIK) is detached to Hainan Island.
9 June 1942:
At 1200, arrives at Cape St. Jacques.
11 June 1942:
At 1400, departs Cape St. Jacques escorting convoy No. 411 consisting of MAEBASHI MARU and two unidentified merchant ships.
17 June 1942:
At 1000, arrives at Mako.
21 June 1942:
At 1200, departs Mako escorting convoy No. 315 consisting of IJA transport KINKASAN MARU.
28 June 1942:
At 1000, arrives at Cape St. Jacques.
2 July 1942:
At 0800, departs Cape St. Jacques escorting convoy No. 510 consisting of KYOKUSEI MARU and one unidentified merchant ship.
5 July 1942:
At 1800, arrives at Singapore.
7 July 1942:
At 1000, departs Singapore escorting convoy No. 614 consisting of auxiliary oiler KIYO MARU, IJA transport TOKO MARU and three unidentified merchant ships.
10 July 1942:
At 1000, arrives at Cape St. Jacques.
14 July 1942:
At 1600, departs Cape St. Jacques escorting convoy No. 420 consisting of IJA TOKO MARU and one unidentified merchant ship.
20 July 1942:
At 1800, arrives at Mako.
23 July 1942:
At 1200, departs Mako escorting convoy No. 322 consisting of CHIKUZEN, KINE and NITTAI MARUs.
29 July 1942:
At 1200, arrives at Cape St. Jacques.
3 August 1942:
At 1500, departs Cape St. Jacques escorting convoy No. 425 consisting of ATAGO, DENMARK, OHIO and TOYAMA MARUs and TOKIWA MARU No. 1.
5 August 1942:
OHIO MARU detaches at 11-35N, 112-46E and heads towards Haiphong, French Indochina. The ship is torpedoed and sunk later that day by LtCdr Joseph H. Willingham’s (USNA ’26) USS TAUTOG (SS-199) with the loss of 72 crewmen, two gunners and 38 passengers.
10 August 1942:
At 0800, arrives at Mako.
28 August 1942:
At 1400, departs Mako escorting convoy No. 255 consisting of four unidentified merchant ships.
2 September 1942:
Arrives at Sasebo. Enters drydock.
17 September 1942:
Undocked. Departs Sasebo. At 128° and about 3.8 nautical miles off Ainoshima, fires on a floating mine.
18 September 1942:
Arrives at Mutsure.
19 September 1942:
At 1700, departs escorting convoy No. 165 consisting of HITERU, TACOMA, GENOA and RAIKO MARUs and one unidentified merchant ship.
23 September 1942:
At 1400, arrives at Mako.
1 October 1942:
At 1300, departs Mako escorting No. 339 consisting of IJA transport CHINA MARU.
8 October 1942:
At 1600, arrives at Cape St. Jacques.
9 October 1942:
At 0500, departs Cape St. Jacques escorting convoy No. 531 consisting of two unidentified merchant ships.
12 October 1942:
At 1600, arrives at Singapore.
18 October 1942:
At 1000, departs Singapore escorting convoy No. 638 consisting of COLOMBIA MARU and one unidentified merchant ship.
20 October 1942:
At 1600, arrives at Cape St. Jacques.
27 October 1942:
At 1200, departs Cape St. Jacques escorting convoy No. 446 consisting of three unidentified merchant ships.
4 November 1942:
Arrives at Mako.
7 November 1942:
Departs Mako escorting convoy No. 346 consisting of TAITO, KOYU, TAISHO, SHOTO, NITTAI and TAIRYU MARUs and two unidentified merchant ships. Returns to Mako because of engine failure.
11 November 1942:
Rated as the 3rd Escort Unit.
19 November 1942:
At 1200, departs Mako escorting convoy No. 727 consisting of IJA transport ROKKO MARU and civilian tanker TONAN MARU.
23 November 1942:
At 1200, arrives at Manila, Philippines.
28 November 1942:
At 1500, departs Manila escorting convoy No. 909 consisting of one unidentified merchant ship.
1 December 1942:
Rated as eastern escort.
2 December 1942:
Arrives at Tarakan, Borneo, Netherlands East Indies.
3 December 1942:
Departs Tarakan escorting an Army convoy.
8 December 1942:
Arrives at Manila.
13 December 1942:
At 1425, departs Manila escorting convoy No. 826 consisting of civilian tanker TONAN MARU and one unidentified merchant ship.
17 December 1942:
At 1147, arrives at Mako.
19 December 1942:
Departs Mako.
20 December 1942:
Arrives at Takao.
22 December 1942:
At 1330, departs Takao escorting convoy No. 731 consisting of IJA transport TAMISHIMA MARU.
25 December 1942:
At 1325, arrives at Manila.
31 December 1942:
At 1500, departs Manila escorting convoy No. 829 consisting of IJA transport NIKKI and ERIE MARUs and one unidentified merchant ship.
1 January 1943:
At 0820, attacked by LtCdr (later Captain) Philip D. Quirk’s (USNA ’32) USS GAR (SS-206) at 14-29N, 118-59E but sustains no damage. Carries out an anti-submarine sweep and drops depth charges.
5 January 1943:
At 1145, arrives at Takao.
15 January 1943:
Departs Takao escorting convoy No. 734 consisting of IJA transport CHOJO MARU.
18 January 1943:
At 1550, arrives at Manila.
24 January 1943:
At 1400, departs Manila escorting convoy No. 832 consisting of KURAMASAN, GENMEI, CHOJO, and SORACHI MARUs and two unidentified merchant ships.
28 January 1943:
At 1130, arrives at Takao.
30 January 1943:
Departs Takao and arrives at Mako later this day.
1 February 1943:
Departs Mako and arrives at Takao later that day. Departs later escorting convoy No. 230 consisting of unidentified ships.
11 February 1943:
Ends escort of convoy No. 230 at some point.
12 February 1943:
Arrives at Takao.
13 February 1943:
At 1300, departs Takao escorting convoy No. 736 consisting of IJA transport ANYO MARU.
16 February 1943:
At 1800, arrives at Manila.
23 February 1943:
At 1500, departs Manila escorting convoy No. 835 consisting of IJA transport ANYO MARU and civilian tanker TONAN MARU.
1 March 1943:
At 1420, arrives at Takao.
5 March 1943:
At 1000, departs Takao escorting convoy No. 739 consisting of CHOKO, KIMKASAN and LIMA MARUs.
8 March 1943:
At 1200, arrives at Manila.
13 March 1943:
At 1500, departs Manila escorting convoy No. 837 consisting of TSUKIKAWA, KOYU and YULIN MARUs.
16 March 1943:
At 1600, arrives at Takao.
20 March 1943:
Rated as northern escort.
25 March 1943:
At 1000, departs Takao escorting No. 244 consisting of ENJU, ISSHIN, KINKASAN, PANAMA, BRAZIL and MACASSAR MARUs and three unidentified merchant ships.
1 April 1943:
Arrives at Sasebo. Assigned to the Northern Force. Enters drydock.
13 April 1943:
Undocked. Departs Sasebo later this day.
14 April 1943:
Arrives at Moji.
16 April 1943:
At 1530, departs Moji escorting convoy G consisting of ZUISHO, KAZAN, HAGURO, SHOHO, PANAMA MARUs and four unidentified merchant ships.
21 April 1943:
At 1430, arrives at Takao. HAGURO MARU has detached for Kirun.
24 April 1943:
At 1000, departs Takao escorting convoy No. 255 consisting of ANYO, URAL, NANREI, NAGATO MARUs and two unidentified ships.
28 April 1943:
Arrives at Sasebo.
2 May 1943:
Departs Sasebo for Moji.
5 May 1943:
At 1500, departs Moji escorting convoy No. 154 consisting of NITTATSU, LIVERPOOL and TOKUWA MARUs and seven unidentified merchant ships.
10 May 1943:
At 1850, arrives at Takao.
14 May 1943:
At 1500, departs Takao escorting convoy No. 262 consisting of IJA transport ARGUN MARU and seven unidentified ships.
20 May 1943:
At 0655, arrives at Moji.
24 May 1943:
At 1600, departs Moji escorting convoy No. 159 consisting of government owned cargo ships (C-AK) ROZAN (ex-British ANALOCK) and BOKO (ex-British SAGRES) MARUs and HIROTA, MIIKE, TACOMA, MYOGI MARUs and three unidentified merchant ships. The convoy sails at 9 knots.
29 May 1943:
At 1700, arrives at Mako.
1 June 1943:
Attached to Western Force under First Escort Squadron Command instruction No. 81.
2 June 1943:
At 1500, departs Mako escorting convoy No. 396 consisting of auxiliary oiler SHOYO MARU, transports TEIBI, MYOGI, HAVRE and MANSHU MARUs and two unidentified merchant ships.
9 June 1943:
At 0745, arrives at St. Jacques.
15 June 1943:
At 1300, departs St. Jacques escorting convoy No. 586 consisting of auxiliary oilers ATAGO, MURORAN, NICHINAN (5,175 GRT) and EIYO MARUs.
18 June 1943:
At 1126, arrives at Singapore.
26 June 1943:
At 0900, departs Singapore escorting convoy No. 699 consisting of IJA tanker RIKKO MARU, IJA transports HOKUSHO MARU and KONAN MARU No. 1 and one unidentified merchant ship.
28 June 1943:
At 1100, KONAN MARU No. 1 breaks down with engine trouble and eventually returns to Singapore.
29 June 1943:
At 1930, arrives at St. Jacques.
1 July 1943:
Navy (Resv) LtCdr Ito Toshihide is confirmed as CO.
At 1000, departs St. Jacques escorting convoy No. 407 consisting of auxiliary transport HOKUSHO MARU and two unidentified merchant ships.
2 July 1943:
Auxiliary transport KOSEI MARU (2,205 GRT) joins the convoy.
6 July 1943:
At 1200, arrives at Mako.
12 July 1943:
At 1330, departs Mako escorting convoy No. 307 consisting of TSUYAMA, PANAMA MARUs and five unidentified merchant ships.
21 July 1943:
At 0900, arrives at St. Jacques.
25 July 1943:
First Escort Squadron instruction No. 203:
Escort schedule:
From Moji to Takao.
28 Jul ’43: convoy No. 181, destroyer SANAE and patrol boat PB-36.
30 Jul ’43: high speed convoy O, part way, destroyer KARUKAYA.
11 Aug ‘43: high speed convoy Q, part way, patrol boat PB-2.
12 Aug ‘43: convoy No. 186, destroyer KARUKAYA and two groups.
Takao area.
28 ~ 29 July and 1 ~ 7 August: convoy No. 288, two groups, auxiliary gunboat CHOJUSAN MARU and destroyer SANAE.
5 Aug ‘43: high speed convoy T, part way, destroyer KARUKAYA.
26 July 1943:
At 0800, departs St. Jacques escorting convoy No. 413 consisting of two unidentified merchant ships.
31 July 1943:
At 2100, arrives at Takao.
8 August 1943:
At 1100, departs Takao escorting convoy No. 314 and Rinji Toku combined convoy consisting of tankers KONSAN and NITTETSU MARUs, civilian cargo ship FUKUJU MARU, cargo ship KENSEI (ex-British HINSANG) MARU, auxiliary transport KOTO MARU No. 2 GO, IJA transport HAMBURG, TAIAN, YULIN, HOREI, LONDON and RYUYO MARUs.
10 August 1943:
Navy (Resv) Lt Kawamoto Kazuo is appointed CO.
11 August 1943:
KOTO MARU No. 2 GO and YULIN MARU detach from the convoy for Yulin.
14 August 1943:
Arrives at St. Jacques.
15 August 1943:
Rating as ship No. 27 abolished under First Escort Squadron instruction No. 20.
18 August 1943:
Departs St. Jacques escorting convoy No. 419 consisting of tanker KYOKUYO MARU and cargo ships SHOTO, KINMON, SAINAN, GYOYU MARUs and one unidentified merchant ship.
25 August 1943:
At 0900, arrives at Mako.
31 August 1943:
At 1300, departs Mako escorting convoy No. 298 consisting of TAKETOYO and RONSAN MARUs and seven unidentified merchant ships.
5 September 1943:
At 1000, arrives at Moji.
13 September 1943:
At 1445, departs Moji with torpedo boat MANAZURU escorting convoy No. 197 consisting of HONAN, TAKETOYO, KYOKUYO, SAINEI, RIKKO, SHOGEN, KINREI, KOSO and TANGO MARUs.
15 September 1943:
The convoy calls at Kagoshima.
17 September 1943:
The convoy departs Kagoshima. Thereafter, steering gear breaks down in worsening weather.
18 September 1943:
Arrives at Naze, Amami Oshima. A huge typhoon strikes anchorage. KYOKUYO, TAKETOYO, KOSO, KINREI and TANGO MARUs are all driven ashore, as is TOMITSU MARU, that is also sheltering at Naze. KYOKUYO, KOSO and TANGO MARUs are eventually lost.
19 September 1943:
At 2215, dragging anchor due to typhoon.
20 September 1943:
At 0028, most of the manually operated gears are missing. Unable to steer. At 0045, runs aground S Tategami lighthouse. At 2335, crew refloats ship.
25 September 1943:
Departs Naze.
26 September 1943:
At 1400, arrives at Sasebo. Enters Sasebo Navy Yard drydock for steering gear and engine repairs.
4 November 1943:
Repairs are completed. Undocked. Departs Sasebo later this day.
5 November 1943:
Arrives at Moji.
7 November 1943:
At 1400, departs Moji escorting convoy No. 112 consisting of ADEN, CHIHAYA, KINE MARUs and three unidentified ships.
12 November 1943:
At 1400, arrives at Takao.
15 November 1943:
Attached to General Escort Command in Vice Admiral Kishi Fukuji’s, (40) First Escort Fleet.
17 November 1943:
Departs Takao and arrives at Mako later that day.
21 November 1943:
At 1540, departs Mako escorting convoy No. 339 consisting of USSURI, ARABIA, ANYO and YUHO MARUs and three unidentified merchant ships.
26 November 1943:
At 1000, arrives at St. Jacques. Departs there and calls at Saigon, French Indochina (now Ho Chi Minh City, Vietnam). Arrives back at St Jacques later that day.
3 December 1943:
At 1200, departs St. Jacques escorting convoy No. 446.
10 December 1943:
Receives instructions for installing two Type 93 13.2mm single MGs under Secretary Cabinet instruction No. 6162.
11 December 1943:
At 1200, arrives at Yulin, Hainan Island, China.
13 December 1943:
At 1800, departs Yulin.
18 December 1943:
At 0200, arrives at Mako.
24 December 1943:
Departs Mako and arrives at Takao later this day.
25 December 1943:
At 1200, departs Takao escorting convoy No. 348 consisting of SHOBU, NICHIREI, SARAWAK, PEKING MARUs and five unidentified merchant ships. En route NICHIREI MARU is detached for Basuo, Hainan Island.
31 December 1943:
At 0800, arrives at St. Jacques.
1 January 1944:
Departs St. Jacques and arrives at Saigon later that day.
5 January 1944:
Departs Saigon on an anti-submarine sweep.
8 January 1944:
Arrives at St. Jacques.
9 January 1944:
Departs St. Jacques and arrives at Saigon later this day.
14 January 1944:
Departs Saigon and arrives at St. Jacques later that day.
16 January 1944:
At 1000, departs St. Jacques escorting convoy No. 457 consisting of KIKUSUI, TAIRYU, KONSAN MARUs and six unidentified ships.
17 January 1944:
Arrives at Cam Ranh.
18 January 1944:
Departs Cam Ranh.
26 January 1944:
At 1500, arrives at Takao.
1 February 1944:
At 1000, departs Takao escorting convoy TAMA-01 consisting of SAN DIEGO, KACHOSAN, KANTO MARUs and four unidentified merchant ships.
5 February 1944:
At 1300, arrives at Manila.
7 February 1944:
Departs Manila on an anti-submarine sweep.
8 February 1944:
At 0800, meets at sea and begins escorting convoy TAMA-02 consisting of NAGATA, TACHIBANA, KIKUSUI MARUs and OGURA MARU No. 1.
9 February 1944:
At 1230, arrives at Manila.
12 February 1944:
At 1500, departs Manila escorting convoy MATA-04 consisting of SHINSEI MARU No. 5 and KACHOSAN MARU.
15 February 1944:
At 1830, arrives at Takao.
21 February 1944:
At 1800, departs Takao escorting convoy TASA-05 consisting of IJA transport TENSHIN MARU and three unidentified merchant ships bound for Saigon, and TOYO MARU No. 3 (unconfirmed), KYOEI MARU No.5, RAKUYO, OYO and BISAN MARUs. The convoy stops at nearby An Ping for the night.
22 February 1944:
At 0700, departs An Ping.
25 February 1944:
At 1800, arrives at Yulin.
4 March 1944:
At 0800, departs Yulin escorting convoy YUTA-01 consisting of WALES, SAIHO and FUKKO MARUs.
8 March 1944:
At 0830, arrives at Takao.
16 March 1944:
At 1000, departs Takao escorting convoy TASA-10 consisting of NISSHIN, HIOKI, SARAWAK, YASUKUNI, HAKUSHIKA, KENSEI MARUs, HISHI MARU No. 3 and three unidentified merchant ships.
18 March 1944:
At 0100, CHOJUSAN MARU sights an enemy submarine in 20-56N, 116-00E.
20 March 1944:
HIOKI and YASUKUNI MARUs detach for Yulin.
21 March 1944:
At 1630, arrives at Cam Ranh.
22 March 1944:
At 1130, departs Cam Ranh.
23 March 1944:
At 1000, arrives at St. Jacques.
27 March 1944:
At 1000, departs St. Jacques escorting convoy SASHI-14 consisting of NISSHIN, TATEISHI, TSURUSHIMA and ZUISHO MARUs. TATEISHI MARU tows kaibokan TSUSHIMA.
[2] 31 March 1944:
Naval tug KURUSHIMA arrives and takes over tow of TSUSHIMA. At 1330, arrives at Singapore.
3 April 1944:
Departs Singapore.
6 April 1944:
Arrives at St. Jacques.
9 April 1944:
Departs St. Jacques escorting convoy SATA-17 consisting of MANTAI MARU and two unidentified merchant ships.
10 April 1944:
Arrives at Cam Ranh. Convoy SATA-17 merges with SATA-14, consisting of six unidentified merchant ships escorted by subchaser CH-19. TOTTORI MARU also joins the convoy at this point.
11 April 1944:
Departs Cam Ranh. Subchaser CH-41 joins the escort. At 1515, kaibokan CD-8 meets up with the convoy
13 April 1944:
Subchaser CH-41 detaches and returns to Cam Ranh.
16 April 1944:
Second Class destroyer ASAGAO meets up with the convoy and starts escorting. At 1800, torpedo boat HATSUKARI meets up with the convoy and starts escorting.
17 April 1944:
At 0200, torpedo boat HATSUKARI ends escort and heads towards Takao.
18 April 1944:
At 1900, arrives at Takao with the merged convoy.
28 April 1944:
At 1300, departs Takao with destroyer HARUKAZE and minesweeper W-17 escorting TAMA-17 consisting of NITTATSU, TAKEGAWA, WALES, SAN LUIS, TAKETOYO, BELGIUM, PEKING, SHIROGANESAN, YAMAHAGI, KUROGANE, SHIROTAE, KENNICHI, and TSUSHIMA MARUs. Convoy TAMA-17A consisting of NANSHIN MARU No. 6 and two unidentified merchant ships sailed close to convoy part of the way and were afforded escort protection.
29 April 1944:
Destroyer ASAKAZE joins the escort. At 2155, LtCdr Anton R. Gallaher's (USNA ’33) USS BANG (SS-385) torpedoes and sinks IJA transport TAKEGAWA MARU at 19-20N, 118-50E. Seven crewmen are KIA. Also lost are 17 Daihatsu barges and two lighters.
30 April 1944:
At 0430, Gallaher torpedoes and sinks civilian tanker NITTATSU MARU, carrying 250 tons coal at 19-22N, 118-45E. Four crewmen are killed.
2 May 1944:
At 1300, arrives at Manila with convoy TAMA-17.
2 ~ 6 May 1944:
Undergoes repairs.
7 May 1944:
Departs Manila.
8 May 1944:
At 1830, at or near Ulugan Bay, Palawan, Philippines joins escort of convoy MI-02 consisting of auxiliary oiler MATSUMOTO, TACHIBANA, NITTETSU, HAKUBASAN, SANKO (YAMAKO), SHINCHO, TAKETSU (BUTSU) and TENSHIN MARUs, and OGURA MARU No. 1 and YAMAMIZU MARU No. 2, cargo KENSEI, TAIHEI, AKAGISAN and TAIYU MARUs and transport KURENAI MARU and escorted by kaibokan AWAJI, torpedo boat SAGI and patrol boat PB-38.
10 May 1944:
At 1300, arrives at Manila.
13 May 1944:
At 0552, departs Manila with kaibokan AWAJI, torpedo boat SAGI and auxiliary gunboat PEKING MARU, escorting convoy MI-02 now also containing tankers MATSUMOTO, TACHIBANA, NITTETSU, HAKUBASAN, SANKO (YAMAKO), SHINCHO, and TAKETSU (BUTSUMARUs and OGURA MARU No. 1 and YAMAMIZU MARU No. 2 and cargo ship SEISHO MARU. At 0815, patrol boat PB-38 joins the escort.
15 May 1944:
At 1515, an unidentified auxiliary subchaser joins the escort.
16 May 1944:
At 1530, patrol boat PB-38 detaches. Arrives at Takao at 1705. CHOJUSAN MARU is detached.
23 May 1944:
At 1200, departs Takao with kaibokan ETOROFU, CD-2 and CD-17 escorting convoy TAMA-19 consisting of tankers MATSUMOTO, MEDAN, RIKKO, IKUTA, KONSAN MARUs, cargo ships DAIRIN, SHIRAMINE and TATSUYASU, KANKYO, NISSHU, MIIKESAN, KOAN, YUKI, ATSUTA, GENKAI, TAMAHOKO and CHINZEI MARUs and five unidentified merchant ships..
26 May 1944:
At 1100, arrives at Manila. Then, enters dock for maintenance and repairs.
14 June 1944:
Undocked. Departs Manila escorting convoy MAYU-03 consisting of MIYAJIMA MARU and four unidentified merchant ships. Later at some point, loses contact with the convoy .
E 15 June 1944:
SHIMUSHU and kaibokan FUKUE meet up and begin escorting convoy MAYU-03.
19 June 1944:
Arrives at St. Jacques.
23 June 1944:
Departs St. Jacques escorting convoy SAMA-07. Boiler fan malfunctions. Loses contact with the convoy.
27 June 1944:
Arrives at Saigon.
27 ~ 8 July 1944:
Undergoes faulty boiler fan repairs.
11 July 1944:
At 1600, departs St. Jacques with subchaser CH-21 escorting convoy SAMA-09 consisting of ROKKO, MIKASA and YUKI MARUs.
17 July 1944:
At 2100, arrives at Manila.
21 July 1944:
While escorting convoy YUTA-09, auxiliary gunboat PEKING MARU runs aground at 17-31N 120-22E, around 3.8 nautical miles SSW Vigan, Luzon, Philippines.
23 July 1944:
Departs Manila on auxiliary gunboat PEKING MARU rescue mission. Arrives on stranding location later this day
27 July 1944:
Ends PEKING MARU assistance and departs on a rescue mission for a ship (likely IJA transport TOSAN MARU) of convoy HI-68. Thereafter (likely after sinking of TOSAN MARU) joins escort of convoy MI-10 consisting of tankers HAKUBASAN, MATSUMOTO, SHUNTEN, CHIYODA, KOSHIN, KOTOKU, NICHINAN (1945 GRT), OEI MARU and KYOEI MARU No. 6 and SHIMOTSU MARUs and DAIZEN, HIDA, HINAGA, KENZUI, TEIFU (ex-French BOUGAINVILLE), KAKOGAWA, TSUKUBASAN, ROKKO, RASHIN, KUROGANE, FRANCE, MYOGI and FUYUKAWA MARUs, WAKO GO and UNYO MARU No.7 and eleven unidentified ships, escorted by destroyer ASAKAZE, kaibokan YASHIRO and CD-3, minelayer MAEJIMA and auxiliary gunboat KAZAN (HUASHAN) MARU. Later CD-20 also joins the escort.
[3] 28 July 1944:
At 1040, LtCdr Francis D. Walker's (USNA ’35) USS CREVALLE (SS-291) torpedoes and sinks HAKUBASAN MARU with 7351-tons of oil and 710-tons of rubber at 16-28N 119-38E. Three crewmen are KIA.
2 August 1944:
Arrives at Takao. NICHINAN (1,945 GRT) and MATSUMOTO MARUs, ASAKAZE and YASHIRO detach. SEIGA and HAKOZAKI MARUs join.
4 August 1944:
At 1300, departs Takao with second class destroyer KURETAKE, Minelayer MAESHIMA, CD-3, CD-17 and CD-20 and auxiliary gunboat HUASHAN (KAZAN, unconfirmed) escorting convoy MI-10 now consisting of SHUNTEN, CHIYODA, SHIMOTSU, DAIZEN, HIDA, FUYUKAWA, SEIGA, HAKOZAKI, KENZUI, TEIFU (ex-BOUGAINVILLE), KOSHIN MARUs and WAKO GO ( ex-HOHSING) and seven others, names unknown but possibly including OEI, KAKOGAWA, TSUKUBASAN and ROKKO MARUs and KYOEI MARU No. 6 (’42, 1,178 GRT) and UNYO MARU No. 7.
10 August 1944:
At 0200, CD-20 detaches and heads for Sasebo. At 0730, KURETAKE detaches and heads for Sasebo. At 1130, arrives at Moji with the convoy.
E8 ~ 12 August 1944:
Departs Moji.
12 August 1944:
Under command of the Fourth Escort Squadron. Arrives at Sasebo. Later attached to the Fourth Escort Squadron, Supply Unit.
1 September 1944:
Under repairs.
7 September 1944:
Scheduled to escort SOSHU and HAGIKAWA MARUs departing Sasebo on 9 Sep ‘44 for Koniya, Amami-Oshima and Naha, Okinawa under Fourth Escort Squadron instruction No. 77.
9 September 1944:
Departs Sasebo escorting convoy KANA-402 consisting of SOSHU and HAGIKAWA MARUs.
10 September 1944:
Arrives at Kagoshima.
13 September 1944:
Departs Kagoshima still in same convoy with minelayers NUWAJIMA and TSUBAME, auxiliary minesweeper TAKUNAN MARU No.1 and auxiliary subchaser NAGATO MARU as additional escorts.
14 September 1944:
Arrives at Koniya. SOSHU MARU detaches as do minelayer NUWAJIMA and auxiliary subchaser NAGATO MARU.
15 September 1944:
Arrives at Seso.
19 September 1944:
At 0100 (ETD), the convoy departs Koniya. At 1900 (ETA), arrives at Sesoko, Seseko Island.
20 September 1944:
At 0600 (ETD), departs Sesoko and at 0900 (ETA), arrives at Naha.
21 September 1944:
Scheduled to escort four ‘Kitakami ’ vessels and disperse them in Seso, Kekeromajima on 22 Sep ‘44 under Fourth Escort Squadron instruction No. 10.
22 September 1944:
Vessels bound for Seso under Fourth Escort Squadron instruction No. 10 wait at Sesoko under Fourth Escort Squadron instruction No. 11.
25 September 1944:
Departs Naha.
27 September 1944:
Arrives back at Naha.
12 October 1944:
Arrives at Sasebo.
18 October 1944:
Departs Sasebo.
19 October 1944:
Arrives at Kagoshima.
21 October 1944:
At 1200, departs Kagoshima with torpedo boat MANAZURU, kaibokan CD-30, subchaser CH-49, storeship KINESAKI, minesweeper W-15, auxiliary minesweepers SHONAN MARU No. 16, TOSHI MARU No. 7 and HIMESHIMA MARU escorting convoy KATA-916 consisting of storeship MUROTO and TOMITSU, EDOGAWA, BANSEI, TENSHO, AMAKUSA, SHINTON, SANKA, SANJIN, HAKKA, KAZAN, TORAI, TAIKYU, SAKISHIMA, RYUKYU, KANKYO and AMOY MARUs and HAKUTETSU MARU No. 11. CHOJUSAN MARU is apparently carrying cargo rather than escorting.
22 October 1944:
At 0730, LtCdr (later Vice Admiral) Vernon L. Lowrance’s (USNA ’30) USS SEA DOG (SS-401) torpedoes and sinks Fleet storeship MUROTO at 29-18N, 129-44E with unknown casualties. Lowrance also torpedoes and damages TOMITSU MARU. TORAI MARU takes TOMITSU Maru in tow. The convoy then shelters in Kasari Bay, Amami Oshima.The convoy’s escorts and aircraft then subject USS SEA DOG to a long and heavy counterattack in which 109 depth-charges are dropped, but Lowrance evades and USS SEA DOG escapes. AMOY MARU and RYUKYU MARU detach at Kasari Wan.
25 October 1944:
At 1230, arrives at Naha with the convoy.
E26 October ~ 2 November 1944:
Departs Naha.
3 November 1944:
Departs Kagoshima with torpedo boat MANAZURU, subchaser CH-49, minesweeper W-15, auxiliary minesweepers SEKI and CHITOSE MARUs, TAKUNAN MARU No. 3, BANSHU MARU No. 51, TOSHI MARU No. 7, CHOUN MARU No. 8 and SHONAN MARU No. 16, auxiliary patrol boats TAIAN MARU, auxiliary subchaser RYUSEI MARU escorting convoy KATA-322 consisting of KAIRYU, KINZAN, KEIUN, KENJO, KEIJO, SEIZAN, DAISEI, SOSHU, and MALAY, KEIZAN, NICHIRIN (ex-British MATA HARI), DAISHIN (1,306 GRT), HIKOSAN MARUs, HOEI MARU No. 5 and TAMON MARU No. 12. CHOJUSAN MARU’s inclusion is unconfirmed.
6 November 1944:
Arrives at Naha.
7 November 1944:
Departs Naha in NAKA-713 convoy also consisting of DAISHIN and EDOGAWA MARUs and probably KEIUN, RYUKYU, SEIZAN MARUs, HOEI MARU No. 5 and six unknown merchant ships escorted by auxiliary netlayer SHINTO MARU No. 2, and auxiliary minesweepers BANSHU MARU No. 51, TAKUNAN MARU No. 3 and HIMESHIMA MARU. It appears as if CHOJUSAN MARU was again carrying cargo, some of the ships, notably RYUKYU and SEIZAN MARUs may have detached before the attack on 9 Nov ‘44.
9 November 1944:
Cdr (later Rear Admiral) Charles E. Loughlin's (USNA '33) USS QUEENFISH (SS-393) sights a convoy consisting of 3 ships escorted by 5 escorts at 31-15N, 129-10E, around 13.5 nautical miles WNW Sparrow (Suzume) Island, Uji Islands. Loughlin fires three torpedoes at a transport. All three hit CHOJUSAN MARU and she subsequently sinks. One crewman is KIA.
10 January 1945:
Removed from the Navy’s list under instruction No. 35.

Authors' Notes:
[1] NRT is a ship's cargo volume capacity expressed in "register tons", one of which equals to a volume of 100 cubic feet (2.83 m3). It is calculated by subtracting non-revenue-earning spaces i.e. spaces not available for carrying cargo, for example engine rooms, fuel tanks and crew quarters, from the ship's gross register tonnage (GRT). Net register tonnage (NRT) is not a measure of the weight of the ship or its cargo, and should not be confused with terms such as deadweight tonnage or displacement.
[2] On 1 Mar ’44, TSUSHIMA collided with IJA transport TOKUSHIMA MARU. 26 feet of the ship's stern were cut off and two NCO's and four enlisted men were KIA. Without rudder and propellers TSUSHIMA was immobilized but damage control and emergency repairs were carried out at Nha Be below Saigon.
[3] On 26 Jul ’44, TOSAN MARU was torpedoed by LtCdr Francis D. Walker’s (USNA ’35) CREVALLE (SS-291). She sank the following day with the loss of nine crewmen, eight gunners and 18 passengers.
Thanks go to Gengoro S. Toda of Japan.

- Gilbert Casse, Berend van der Wal and Peter Cundall.

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