Japanese Auxiliary Gunboats

KOKAI HOKAN!

(CHOSA MARU, prewar)

IJN CHOSA MARU:
Tabular Record of Movement

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

1921:
Sakurajima. Laid down by Osaka Tekkosho Shipyard as a 2,540-tons passenger ship for Osaka Shosen K.K.
18 June 1921:
Launched and named CHOSA MARU.
29 August 1921:
Completed and registered at Osaka. Her gross registered (GRT) tonnage and net registered tonnage (NRT) respectively are 2,540-tons and 1,564-tons. Her call sign is JHYA. [1]
24 October 1921:
In service on the Osaka ~ Tianjin (Tientsin), China route.
1922:
Her NRT is changed to 1,558-tons. [1]
September 1923:
Temporarily in service on the Keihin ~ Hanshin route due to the Great Kanto earthquake.
20 October 1923:
In service on the Osaka ~ Tianjin route.
E October ~ December 1923:
Her NRT is changed to 1,557-tons. [1]
1927:
Her GRT and NRT are changed respectively to 2,538-tons and 1,555-tons. [1]
21 February 1927:
In service on the Osaka ~ Tianjin route.
19 December 1933:
A fire accident occurs on the Foochow (now Fuzhou), China ~ Kirun, Formosa (now Keelung, Taiwan) route.
April 1935:
In service on the Takao (now Kaoshiung), Formosa ~ Shanghai, China route.
17 August 1937:
In service on the Foochow ~ Kirun route.
18 July 1938:
Arrives at Amoy (now Xiamen), China.
3 August 1939:
Arrives at Shanghai.
1 September 1939:
Her owners and registry port are respectively changed to Toa Kaiun K.K. and Tokyo.
8 October 1940:
Requisitioned by the IJN.
(CHOSA MARU as an auxiliary gunboat – Berend Van der Wal collection)

1 November 1940:
Registered as an auxiliary gunboat with minelaying capabilities attached to the Sasebo Naval District under order No. 770. Navy LtCdr Morimoto Shinichi (40) is temporarily appointed CO that same day.
5 November 1940:
Navy LtCdr Morimoto is confirmed as CO.
15 November 1940:
Conversion to military duty begins at Osaka Iron Works K.K. Shipyard. Designated as an auxiliary gunboat under instruction No. 830. Attached to the First Gunboat Division under instruction No. 837.
1 December 1940:
Conversion is completed.
27 December 1940:
Rated as gunboat No. 14 under 1st Base Force instruction No. 47.
15 January 1941:
Designated as an auxiliary gunboat engaged in minelaying operations under instruction No. 56.
23 March 1941:
Departs Tokuyama for mid Chinese waters.
4 April 1941:
Arrives at Karatsu.
10 June 1941:
Departs Sasebo for southern Chinese waters.
8 July 1941:
Arrives at Mako, Pescadores.
12 July 1941:
Departs Takao for southern Chinese waters.
7 September 1941:
Arrives at Sasebo.
15 October 1941:
Attached to the First Gunboat Division under instruction No. 1250.
31 October 1941:
Detached from the First Gunboat Division under instruction No. 1310. Attached to the 9th Base Force.
10 November 1941:
Departs Sasebo for southern Chinese waters and then French Indochina (now Vietnam).
1 December 1941:
Attached to Vice Admiral Ozawa Jisaburo (37) Southern Expeditionary Fleet in Rear Admiral (later Vice Admiral) Hiraoka Kumeichi (39), 9th Base Force. Rated as ship No. 3. Rated as Malaya Reserve Unit, Mine Unit, Base Force Unit. At 1715, departs Samah (Sanya) Hainan Island, China with auxiliary minesweeper tender EIKO MARU and three minesweepers for NW tip of Borneo, Netherlands Indies (now Indonesia). Lays mines in the Api Passage.
9 December 1941:
Arrives at Camranh, French Indochina.
10 December 1941:
Assigned to stay at Cam Ranh Bay (now Vinh Cam Ranh) from 11 till 13 Dec ‘41 and remain vigilant. (Unit, commanders, troops, procedures) Commander Third Minesweeper Division, 1st Patrol Team: SHIMUSHU, TATSUYAMA MARU, CHOSA MARU, EIFUKU MARU. Patrol outside the bay with one ship all the times under Malaya Force Order No. 30.
3 January 1942:
Attached to Southern Expeditionary Fleet, 9th Base Force. Departs Cam Ranh Bay.
4 January 1942:
Arrives at Poulau Condore, French Indochina.
8 January 1942:
Departs Poulau Condore.
10 January 1942:
Arrives at Cam Ranh Bay.
11 January 1942:
Attached to Anambas, Netherlands East Indies (now Indonesia) Base Force, Base Unit under Malaya Command Order No. 15.
12 January 1942:
Departs Cam Ranh Bay.
13 January 1942:
Arrives at Poulau Condore.
24 January 1942:
At 1005, departs Poulau Condore with minelayer HATSUTAKA and auxiliary minesweeper tender EIKO MARU.
27 January 1942:
Arrives at Anambas.
10 February 1942:
Attached to Vice Admiral Ozawa Jisaburo (37) First Southern Expeditionary Fleet, 10th Special Base Force.
17 February 1942:
Receives Malay Force wireless command No. 136:
Implement operations to open the Singapore and Malacca Strait waterways: 9th Base Force CO is in command of (1st Minesweeper Division, CHOSA MARU, 91st Subchaser Division missing), 20th Destroyer Division (AMAGIRI and ASAGIRI missing) 41st Minesweeper Division, 44th Minesweeper Division, auxiliary minesweeper (2 auxiliary patrol boats, 4 fishing boats missing. Conduct quickly, gather at anchorage S Mapor Island (East Bintan Island), Singapore main waterway and Malacca Strait. Open the waterway. The assault force, SHIMUSHU, CHOSA MARU and fishing vessel No. 2 will be under command of 3rd Minesweeper Division CO.
Order No. 6 of the First Guard letter:
1 - 20th Destroyer Division (AMAGIRI and ASAGIRI missing), 11th Destroyer Division and 41st Minesweeper Division (2nd Team missing) are placed under 9th Base Force command. 2 - After completing mission, the area should be guarded. CHOSA MARU anchors near Muntok. 3 - CHOSA MARU CO is in charge of the captured ships.
First Guard Order No. 4:
CHOSA MARU CO is to handle the ships seizure at Muntok.
18 February 1942:
At 0900, subchaser CH-7 hands over a captured Dutch S.S. At 2000, under First Guard command.
23 February 1942:
Departs off Muntok with 18 captured vessels. At 2000, anchors at 180°, 38’ of Saya Island.
24 February 1942:
At 0800, anchors. Disposes of one floating mine near Saya Island later this day. At 2000, anchors at 235°, 3’ of Jan Horn lighthouse.
25 February 1942:
Placed under 10th Special Base Force command under Malaya Unit wireless order No. 151.
At 0900, departs anchorage. Disposes of one floating mine 30°, 6’ of Jan Horn lighthouse later that day. At 1900, anchors at 00-36N, 104-56E. At 2100, destroyer ASAGIRI ends escort.
26 February 1942:
At 0800, departs anchorage. At 1400, inner fireboat No. 262 flooded and sank. At 1700, anchors at 15°, 5.5’ of Bellaton Square lighthouse.
27 February 1942:
At 0830, anchors. At 0855, during round trip sinks a small motor boat. Arrives at Singapore later this day.
5 March 1942:
Operation T. The invasion of Northern Sumatra. Malaya Second Troop escort.
5 ~ 22 March 1942:
Performs Singapore Area Base Escort Unit T, D and U operations.
14 March 1942:
Departs Labuhanruku, (now Laboehanroekoe) Sumatra.
17 March 1942:
Arrives at Belawan, Sumatra.
22 March 1942:
Departs Singapore for Belawan escorting a convoy with auxiliary minesweepers RUMOE and OTOWA MARUs consisting of 13 unidentified merchant ships
26 March 1942:
Arrives at Singapore.
10 April 1942:
Attached to Vice Admiral Takahashi Ibo’s (36) Southwestern Area Fleet in Vice Admiral Ozawa Jisaburo (37) First Southern Expeditionary Fleet, 10th Special Base Force.
13 April 1942:
Operation U, third convoy escort. Departs Singapore’s commercial port for Penang, British Malaya (now Malaysia) with the convoy consisting of TAIKAI, HAMBURG, TEIKAI, HOKURYU, ANYO, GINYO, KUWAYAMA, KOCHI, KENKOKU, SAMARANG, SUEZ, TAIZAN, BUYO, HAVRE, BRAZIL, PENANG, MONTREAL, YAWATA, YONEYAMA, HOKUROKU, ENGLAND, ARGUN, MEIGEN MARUs, SHINTO MARU No. 1 and four unidentified merchant ship also escorted by minelayer HATSUTAKA and other unidentified escorts.
7 June 1942:
Departs Singapore for Penang escorting a convoy consisting of URAJIO and YOSHINO MARUs. CHOSA MARU is detached en-route.
8 June 1942:
Departs Singapore escorting transports KENKOKU and UMEKAWA MARU’s until 00-45N, 107-10E. Then, escorts IJN transport SHOHEI MARU from Dungun, British Malaya (now Malaysia) to Singapore .
16 June 1942:
Navy LtCdr Shinkai Tsuneo (41) is appointed CO.
12 July 1942:
Departs Singapore with subchaser CH-9 and kaibokan SHIMUSHU escorting convoy S-2 consisting of SHINYU and SHINRYU MARUs and SUGI MARU No. 5 and three unidentified merchant ships of which SHINYU and SHINRYU MARUs and SUGI MARU No. 5 are en route to Rangoon and the others to Belawan and Sabang.
31 July 1942:
Departs Singapore escorting convoy S-5 consisting of IJA transports TAKUNAN and ZENYO MARU’s bound for Belawan, and three unidentified merchant ships bound for Rangoon.
2 August 1942:
Arrives at Belawan and is detached from convoy.
4 August 1942:
Arrives at Singapore.
8 August 1942:
Escorts convoy S-6 consisting of IJA transports TEIYO (Ex-SAARLAND), SHINYU and SUMATRA MARUs from Singapore to 07-20N, 97-48E. Then escorts convoy R-6 consisting of TAIHEI MARU that departed Rangoon 10 Aug ‘42.
14 August 1942:
Arrives at Singapore.
18 August 1942:
Departs Singapore to take over escort at two ‘MA’ locations. Arrives at Singapore later this day.
25 August 1942:
Departs Singapore escorting an Army convoy. Then takes over escort of another convoy in the Balabac Strait, Philippines.
4 September 1942:
Arrives at Seletar (Singapore Naval port).
11 September 1942:
Departs Singapore.
12 September 1942:
Arrives at Kuching, Sarawak, Borneo, Britsih Malaya (now Malaysia).
15 September 1942:
Departs Kuching escorting IJA transport AMAGIRI MARU.
17 September 1942:
Arrives at Seletar.
20 September 1942:
Departs Singapore.
22 September 1942:
Arrives at Great Natuna Island, Natuna Islands, Riau Archipelago, Netherlands East Indies (now Pulau Natuna Besar,Indonesia). Departs there later that day.
25 September 1942:
Arrives at Seletar.
27 October 1942:
Departs Seletar. Returns there later this day.
30 October 1942:
At 1800, departs Singapore escorting convoy S-18 bound for Rangoon consisting of NICHIMEI, TOYOKAWA, TACOMA, TAGA MARUs and one unidentified merchant ship also escorted by auxiliary subchasers SHONAN MARU No. 11 and SHONAN MARU No. 12 and auxiliary minesweeper CHOUN MARU No. 6 and CHOUN MARU No. 7. At some point over the next two days CHOSA MARU is detached.
1 November 1942:
Rated as an escort unit. At 1030, departs Singapore to meet up with and escort inbound fleet oiler HAYATOMO.
5 November 1942:
At 1715, arrives with fleet oiler HAYATOMO at Seletar.
8 November 1942:
Departs Singapore on a mine disposal mission.
11 November 1942:
Arrives at Seletar.
16 November 1942:
Departs Singapore for Natuna Island.
30 November 1942:
Arrives at Seletar.
2 December 1942:
Departs Keppel (Singapore Commercial port) and arrives at Seletar later that day.
13 December 1942:
Departs Seletar and arrives at Keppel later that day.
31 December 1942:
Departs Keppel and arrives at Seletar later that day.
3 January 1943:
Departs Singapore on an anti-submarine sweep and then escorting auxiliary oiler SAN DIEGO MARU.
5 January 1943:
At 2200, meets up at sea with auxiliary oiler SAN DIEGO MARU and begins escorting her.
8 January 1943:
Arrives at Seletar.
12 January 1943:
Departs Singapore.
16 January 1943:
Arrives at Miri, Borneo, British Malaya, (now Malaysia).
19 January 1943:
Departs Miri escorting auxiliary oiler KYOKUYO MARU.
23 January 1943:
Arrives at Seletar.
26 January 1943:
Departs Singapore.
27 January 1943:
Escorts Fleet oiler NOTORO.
31 January 1943:
At 1540, arrives with Fleet oiler NOTORO at Seletar.
4 February 1943:
Departs Singapore and arrives at Seletar later this day.
2 March 1943:
Departs Keppel.
5 March 1943:
Arrives at Miri.
6 March 1943:
Departs Miri and returns there later that day.
7 March 1943:
Departs Miri and arrives at Victoria Island, Borneo, British Malaya (now Labuan, Malaysia) later this day.
9 March 1943:
Departs Victory Island and arrives at Miri later that day.
10 March 1943:
Departs Miri and returns there later this day.
12 March 1943:
Departs Miri and returns there later this day.
18 March 1943:
Departs Miri.
21 March 1943:
Arrives at Saigon, French Indochina (Now Ho Chi Minh City, Vietnam).
30 March 1943:
Departs Saigon.
2 April 1943:
Arrives off Miri.
3 April 1943:
Departs Miri waters.
4 April 1943:
Hit by a dud torpedo at 04-50N, 114-00E off Baram lighthouse, Borneo, British Malaya, (now Malaysia). Performs Anti-Submarine Warfare. Fires 4 rounds with her guns and drops 2 depth charges.
5 April 1943:
Hit by a dud torpedo at 03-25N, 110-15E off Kuching. Performs Anti-Submarine Warfare. Fires 8 rounds with her guns and drops 6 depth charges.
6 April 1943:
Arrives at Kuching.
7 April 1943:
Departs Kuching.
9 April 1943:
Arrives at Seletar.
14 April 1943:
Departs Singapore and arrives at Berhala Strait, Netherlands Indies.
15 April 1943:
Departs Berhala Strait and arrives at Ponkoni later that day.
16 April 1943:
Departs Ponkoni and arrives at Seletar later this day.
17 April 1943:
Departs Singapore and arrives at Keppel later that day. Enters drydock No. 5.
25 April 1943:
Undocked.
29 April 1943:
Departs Singapore.
30 April 1943:
Arrives at Seletar.
5 May 1943:
Departs Singapore.
6 May 1943:
Arrives at Malacca. Departs there later this day.
7 May 1943:
Arrives at Biai . Departs there later that day.
8 May 1943:
Arrives at Durian Strait. Departs there and arrives at Pinang, Bintan Island later this day.
9 May 1943:
Departs Pinang.
10 May 1943:
Arrives at Seletar.
14 May 1943:
Departs Singapore and arrives at Durian Strait later that day.
15 May 1943:
Departs Durian Strait.
16 May 1943:
Arrives at Seletar.
18 May 1943:
Departs Singapore.
21 May 1943:
Arrives off Victoria Island.
22 May 1943:
Transfers to Victoria pier later this day.
23 May 1943:
Departs Victoria and arrives off Victoria Island later that day.
24 May 1943:
Departs Victoria Island waters.
26 May 1943:
Arrives at Seletar.
28 May 1943:
Departs Singapore.
29 May 1943:
Arrives at Durian Strait.
30 May 1943:
Departs Durian Strait.
31 May 1943:
Arrives at Seletar.
4 June 1943:
Departs Singapore and arrives at Durian Strait later this day.
6 June 1943:
Departs Durian Strait and arrives at Seletar later that day.
10 June 1943:
Departs Singapore and arrives at Linga anchorage later this day.
11 June 1943:
Departs Linga anchorage and arrives at Riau Channel later that day.
12 June 1943:
Departs Riau Channel and arrives at Berhala later this day.
13 June 1943:
Departs Berhala and arrives at Muntok later that day.
14 June 1943:
Departs Muntok and arrives at Palembang later this day.
16 June 1943:
Departs Palembang and arrives at Muntok later that day.
17 June 1943:
Departs Muntok and arrives at Singkep later this day.
18 June 1943:
Departs Singkep and arrives at Riau Channel later that day.
19 June 1943:
Departs Riau Channel and arrives at Seletar later this day.
2 July 1943:
Under command of 9th Base Force. Assigned to convoy escort until 20 Jul ‘43.
19 July 1943:
Departs Rangoon escorting a convoy consisting of GENKAI, TAMATSU and YAMABUKI MARUs.
27 July 1943:
Arrives at Prai, near Penang.
29 July 1943:
Under command of 9th Base Force. Assigned to convoy escort.
4 August 1943:
Departs Penang.
9 August 1943:
Arrives at Penang.
11 August 1943:
Departs Penang for Rangoon escorting convoy P-6 consisting of YAMAGIKU, GLASGOW, GENKAI, TAMATSU MARUs and two unidentified merchant ships also escorted by minelayer HATSUTAKA.
14 August 1943:
Detaches to assist the auxiliary submarine tender TEIJU MARU (ex-German V Schiff QUITO). Carries out an anti-submarine sweep.
18 August 1943:
Arrives at Penang.
19 August 1943:
Ltz II (LtCdr) Wopke J. de Vries' HNMS submarine O-24 (P-24) attacks a Japanese ship with 4 torpedoes W Sembilan Islands in position 04-01N, 100-25E. The ship is able to evade them. This ship is the IJN submarine tender TEIJU MARU (ex-German V Schiff QUITO) en-route from Singapore to Penang.
20 August 1943:
Departs Penang on an anti-submarine sweep at the position where TEIJU MARU (ex-German V Schiff QUITO) was attacked. HMNS O-24 sights CHOSA MARU and fires four torpedoes at her of which one hits. Sinks with stern first at 05-09N, 100-10E, about 8.6 nautical miles SSW Penang island near Keng Phu Island. Five crewmen are KIA.
Early October 1943:
Auxiliary salvage ship KAMISHIMA MARU is ordered to salvage guns from CHOSA MARU’s wreck and return to Penang. It is unclear if this actually occurred.
1 November 1943:
Removed from the Navy’s list under instruction No. 2288.
23 May 2014:
Cambodian registered but likely Chinese owned HAI WEI GONG 889 is detained and impounded at Lumut by the Malaysian northern region Marine Department after illegally salvaging CHOSA MARU’s wreck. Besides CHOSA MARU, HAI WEI GONG 889 also illegally salvaged at least four other wrecks: heavy cruiser HAGURO, light cruiser KUMA, KAPAL TAIWAN and KAPAL SIMEN. Of these five wrecks, CHOSA MARU and KUMA’s are completely removed from the seabed.

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.
Thanks go to Gengoro S. Toda of Japan.

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

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