KUSENTEI!

© 2008-2018 Bob Hackett, Sander Kingsepp and Peter Cundall

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8 April 1942:
Nigata. Laid down at the Nigata Iron Works yard as subchaser No. 443.

25 September 1942:
Numbered CH-43. Tentatively attached to Yokosuka Naval District.

11 November 1942:
Launched and renumbered CH-43

7 April 1943:
Completed and registered in the IJN.

1 May 1943:
Reattached to the newly-established 52nd Base Force (Ominato) with the minelayer TOKIWA, CH-41 and others.

3 May 1943:
W-23, W-24, Submarine chaser CH-43 and the minelayer TOKIWA all anchor in Mutsu Wan.

5 May 1943:
All the ships return to Ominato.

15 May 1943:
Departs Ominato and off Kamo Misaki undertakes an anti submarine patrol.

17 May 1943:
Arrives at Otaru.

19 May 1943:
Departs Otaru escorting a Navy convoy to Matsuwa.

22 May 1943:
Arrives off Matsuwa Jima.

27 May 1943:
Departs Matsuwa Jima escorting a Navy convoy back to Otaru.

29 May 1943:
Arrives at Otaru.

30 May 1943:
Departs Otaru for Ominato.

31 July 1943:
At 0800 CH-43 arrivces at Ominato.

14 August 1943:
At 0800 departs Ominato after CH-41, that has departed at 0720.

1 September 1943:
Departs Ominato and anchors outside the port.

2 September 1943:
Returns to Ominato.Departs later that day to nearby Mutsu Wan.

3 September 1943:
Returns to Ominato.

6 September 1943:
Minesweepers W-23 and W-24, submarine chasers CH-41 and CH-43 and minelayer TOKIWA transfer to Mutsu Wan and undertakes training exercises.

11 September 1943:
All ships return to Ominato.

13 September 1943:
Departs Ominato and later that day arrives at Muroran.

14 September 1943:
Departs Muroran escorting a convoy to Nagaura, Tokyo Bay.

17 September 1943:
Arrives at Nagaura.

19 September 1943:
Transfers from Nagaura to Yokosuka. Docked.

25 September 1943:
Undocked. Transfer to Nagaura.

26 September 1943:
Transfers from Nagaura to Tokyo Bay.

27 September 1943:
Transfers from Tokyo bay to Nagaura.

29 September 1943:
Departs Nagaura for Ominato escorting a convoy.

2 October 1943:
Arrives at Ominato.

4 October 1943:
Departs Ominato.

5 October 1943:
Arrives at Otaru.

7 October 1943:
Departs Otaru on an anti submarine sweep.

11 October 1943:
La Pérouse/Soya Strait, Northern Japan. At about 0830, the spotter for a 6-inch coast artillery battery on Soya Misaki promontory sights Cdr Dudley W. Morton’s (USNA ’30) USS WAHOO (SS-238) is exiting the Sea of Japan on the surface. The battery opens fire. USS WAHOO submerges and continues on course, but leaves a trail of oil from a previous encounter. The battery commander calls for air support.

About an hour later, an E13A1 Jake" anti-submarine floatplane No. 19 from Wakkanai arrives. At 0920, the Jake detects the widening oil slick and sees the conning tower of the submarine. The E13A1's pilot drops two bombs on USS WAHOO. Two more E13A1s of the same unit arrive and drop a total of six depth-charges. At 1145, the first floatplane directs CH-15 to the scene. At 1203, the submarine is located and CH-15 drops two series of nine and seven depth-charges. At 1218, CH-15 drops a single depth-charge and is relieved by CH-43.

At 1221, CH-43 drops six depth-charges. At 1330, auxiliary minesweeper Wa-18 arrives. As a result of these attacks, USS WAHOO is sunk with all hands at 45-13N, 141-56E. [1]

12 October 1943:
Arrives at Wakkanai.

13 October 1943:
Departs Wakkanai and conducts an anti submarine sweep in the Soya Straits.

15 October 1943:
Off Wakkanai meets up with a convoy.

16 October 1943:
CH-43 and the convoy arrives at Odomari.

19 October 1943:
CH-43 departs Odomari on an anti submarine sweep.

20 October 1943:
Arrives at Wakkanai.

22 October 1943:
Departs Wakkanai and escorts a convoy to Otaru, then immediately returns escorting another convoy.

24 October 1943:
Arrives back at Wakkanai.

25 October 1943:
Departs Wakkanai on an anti submarine sweep of the Soya Straits.

26 October 1943:
Arrives back at Wakkanai.

29 October 1943:
Departs Wakkanai on an anti submarine sweep of the Soya Straits.

31 October 1943:
Arrives back at Wakkanai.

2 November 1943:
Departs Wakkanai on an anti submarine sweep of the Soya Straits.

3 November 1943:
Arrives back at Wakkanai.

5 November 1943:
Departs Wakkanai on an anti submarine sweep.

6 November 1943:
Arrives back at Wakkanai.

8 November 1943:
Departs Wakkanai on an anti submarine sweep and patrol.

9 November 1943:
Arrives at Odomari.

13 November 1943:
Departs Odomari on an anti submarine sweep and patrol.

14 November 1943:
Arrives back at Wakkanai.

16 November 1943:
Departs Wakkanai on an anti submarine sweep and patrol.

17 November 1943:
Arrives back at Wakkanai.

19 November 1943:
Departs Wakkanai on an anti submarine sweep and patrol.

20 November 1943:
Arrives back at Wakkanai.

21 November 1943:
Departs Wakkanai.

22 November 1943:
Arrives at Otaru.

25 November 1943:
Departs Otaru for Ominato on an anti submarine training exercise.

26 November 1943:
Arrives at Ominato.

1 December 1943:
The minelayer TOKIWA, submarine chasers CH-41 and CH-43 and and minesweepers W-23 and W-24 undertake training exercises at sea.

4 December 1943:
All transfer to Mutsu Wan and undertake further training.

6 December 1943:
CH-41 and CH-43 arrive back at Ominato. CH-43 undergoes hull and engine repairs.

23 December 1943:
Departs Ominato on an anti submarine sweep.

26 December 1943:
Arrives at Muroran.

27 December 1943:
Departs Muroran on an anti submarine sweep.

28 December 1943:
Arrives at Muroran.

29 December 1943:
Departs Muroran on an anti submarine sweep.

31 December 1943:
Arrives back at Muroran.

17 January 1944:
Departs Yokohama escorting a convoy.

19 January 1944:
Arrives at Kobe.

20 January 1944:
Departs Kobe.

21 January 1944:
Arrives at Moji.

23 January 1944:
At 1000 CH-43 departs Moji with subchaser CH-41 escorting convoy No. 131 consisting of TOTTORI, NORFOLK, ARABIA, AKAGISAN, USSURI, HAWAII, CHOJO MARUs and two unidentified merchant ships. Later that day tanker TONAN MARU No. 2 joins from Sasebo.

28 January 1944:
At 2400 arrives at Takao.

31 January 1944:
At 1200 CH-43 departs Takao for Cap St Jacques, Indochina with subchaser CH-41 and auxilary gunboat HUASHAN (KAZAN) MARU escorting convoy No. 357 consisting of TSUKUBA, TOTTORI, NORFOLK, ARABIA, AKAGISAN, USSURI, HAWAII MARUs, ANKO GO (ex AN SHING) and four unidentified merchant ships.

4 February 1944:
The convoy arrives at Yulin and CH-43 and HUASHAN (KAZAN) MARU are detached. CH-41 had previously detached and arrived this day at Nha Trang.

8 February 1944:
CH-43 arrives at Camranh Bay.

9 February 1944:
S China Sea, off Southern Indochina. At about noon, while TONAN MARU No. 2 is enroute to Nagasaki, LtCdr (later Cdr) Thomas W. Hogan’s (USNA ’31) USS BONEFISH (SS-223) torpedoes and damages her at 11-30N, 109-08E. Hogan claims four hits out of five torpedoes he fires.

Later that day, USN codebreakers intercept and decrypt a message that reads: "Order to Subchasers No. 21, 41, and 43 to attack the submarine that attacked TONAN MARU No. 2."

CH-41 and CH-43 both depart Camranh Bay later that day on an anti submarine hunt.

11 February 1944:
Both CH-41 and CH-43 arrive at Saigon.

15 February 1944:
CH-41 and CH-43 depart Saigon. CH-43 escorts an unknown convoy then carries out an anti submarine sweep.

27 February 1944:
Arrives at Saigon.

1 March 1944:
CH-21, CH-41 and CH-43 depart Camranh Bay (CH-21 and CH-41) and Saigon (CH-43) escorting combined convoy SATA-06 and SATA-07 from Camranh Bay consisting of MANKO, KENZUI, SAINEI, KOAN MARUs, UNKAI MARU No. 12, and seven unidentified merchant ships.

3 March 1944:
The convoy with all three escorts arrive at Van Phong Bay.

4 March 1944:
The convoy with all three escorts depart Van Phong Bay.

6 March 1944:
Convoy TASA-08 departs Takao for Cap St Jacques, Indochina via Yulin, China auxiliary gunboat PEKING MARU escorting convoy TASA-08 consisting of NICHIREI, LONDON, ISHIKARI, CHEFOO, SAINAN, SHINGU and TOYOKUNI MARUs and one unidentified merchant ship. That same day SATA-06/SATA-07 arrives at Yulin.

7 March 1944:
CH-21 and CH-43 (and possibly CH-41) meet up with TASA-08 convoy.

8 March 1944:
SE of Hong Kong. At 1455, LtCdr (later Cdr) Lowell T. Stone’s (USNA ’29) USS LAPON (SS-260) torpedoes and damages TOYOKUNI MARU carrying Army stores and general cargo. She loses power and goes dead in the water. NICHIREI MARU takes her in tow.

9 March 1944:
At 0150, while NICHIREI MARU is still towing TOYOKUNI MARU, USS LAPON torpedoes NICHIREI MARU. LtCdr Stone also torpedoes and hits TOYOKUNI MARU again. She floods and sinks. 15 crewmen are KIA. At about 0500, NICHIREI MARU sinks. Six escort troopers and 46 crewmen are killed. The escorts, including an aircraft, counterattack, but fail to damage USS LAPON.

10 March 1944:
Arrives at Qui Nhon, French Indochina.

12 March 1944:
Departs Qui Nhon.

14 March 1944:
Arrives at St Jacques, Indochina.

16 March 1944:
CH-43 arrives at Camranh Bay.

21 March 1944:
CH-43 departs Camranh Bay and escorts a convoy.

28 March 1944:
Arrives back at Camranh Bay.

31 March 1944:
Departs Camranh Bay.

1 April 1944:
Arrives at Saigon.

5 April 1944:
Enters drydock at Saigon.

10 April 1944:
Undocked.

17 April 1944:
Departs Saigon on a convoy escort mission.

21 April 1944:
Arrives at Qui Nhon.

23 April 1944:
Departs Qui Nhon on a convoy escort mission with CH-41.

25 April 1944:
Off Nha Trang with CH-41 meets up with minesweeper W-18 escorting an convoy TASA-17, consisting of oiler TENSHIN MARU and cargo ships FRANCE MARU, and likely HOKKA MARU and WAKO GO.

27 April 1944:
At 0934 arrives at St Jacques. At some point very late in the month arrives at Saigon.

1 May 1944:
CH-41 and CH-43 depart Saigon briefly, before returning to port later that day.

6 May 1944:
CH-41 and CH-43 depart Saigon escorting a convoy consisting of NORWAY, TEIYU (ex Italian CARIGNANO) and MURORAN MARUs.

7 May 1943:
At 1300 departs St Jacques.

13 May 1944:
Arrives at Manila.

17 May 1944:
CH-43 and CH-41 depart Manila escorting a convoy consisting of WALES, BIZEN and TOYO MARUs.

20 May 1944:
Arrives at Victoria, Labuan Island.

22 May 1944:
At 0600, departs Victoria.

23 May 1944:
At about 2300, LtCdr (later Cdr) Lowell T. Stone's (USNA ’29) USS LAPON (SS-260) torpedoes and sinks WALES MARU at 07-20N, 109-03E. At the time the ship was carrying Unit 234 of Independent Flight Corps of 1000 men and 50 of them as well as 13 crewmen are killed.

24 May 1944:
At 0244, LtCdr (later Cdr) Lowell T. Stone's (USNA ’29) USS LAPON (SS-260) torpedoes and sinks BIZEN MARU at 07-30N, 109-08E. Three guards and 22 crewmen are killed.

25 May 1944:
Arrives at St Jacques.

28 May 1944:
CH-41 and CH-43 depart St Jacques and later arrives at Saigon.

1 June 1944:
CH-43 departs Saigon escorting a convoy.

6 June 1944:
Arrives at Manila.

9 June 1944:
CH-43 departs Manila with kaibokan SHIMUSHU and FUKUE and subchaser CH-9 escorting convoy MASA-06 consisting of HAKUSHIKA, HAKUBASAN, BEIJU, TENSHIN, TATSUHATO, KAIJUN, KUROGANE, MAYA MARUs and JUNGEN GO.

E 12 June 1944:
SHIMUSHU and FUKUE are detached from the convoy and return to Manila.

13 June 1944:
Arrives at Camranh Bay.

14 June 1944:
Departs Camranh Bay.

E 15 June 1944:
CH-19 is detached from the convoy.

20 June 1944:
Arrives at Singapore. That same day CH-43 that has detached at an unknown point arrives back at Saigon.

25 June 1944:
At 1240, CH-43 departs Saigon with CH-19 escorting convoy SAMA-08 consisting of MAYA, MATSUKAWA and YAMABUKI MARUs.

26 June 1943:
Off Nha Trang Bay. TSURUSHIMA MARU joins the convoy.

30 June 1944:
At 0312, LtCdr (later Captain) Arthur E. Krapf's (USNA ’34) USS JACK (SS-259) torpedoes and sinks TSURUSHIMA MARU. 44 crewmen, 18 gunners and 15 passengers are KIA. The convoy scatters. At 0422, USS JACK torpedoes and sinks MATSUKAWA MARU loaded with brown rice, at 14-25N, 119-45E. Two crewmen, five gunners, 15 troops and 9 passengers are KIA. Later that day, the remaining ships arrive at Manila.

7 July 1944:
CH-19 and CH-43 depart Manila escorting an unidentified convoy.

13 July 1944:
Arrives at St Jacques.

17 July 1944:
Departs Saigon escorting KASAGISAN MARU.

21 July 1944:
Arrives at Singapore.

24 July 1944:
CH-43 departs Singapore escorting convoy SHISA-24 consisting of two unidentified merchant ships.

27 July 1944:
Arrives at St Jacques. Later that day departs St Jacques and arrives at Saigon.

8 August 1944:
CH-43 departs St Jacques escorting convoy SASHI-32 consisting of two unidentified merchant ships.

13 August 1944:
Arrives at Singapore. Docked for repairs.

30 August 1944:
CH-43 departs Singapore escorting convoy SHISA-26 consisting of two unidentified merchant ships.

2 September 1944:
Arrives at St Jacques.

5 September 1944:
Departs Saigon.

6 September 1944:
Arrives at Camranh Bay.

8 September 1944:
Departs Camranh Bay and carries out anti submarine patrols.

10 September 1944:
Returns to Camranh Bay.

12 September 1944:
Departs Camranh Bay escorting a convoy.

15 September 1944:
Arrives at Yulin.

16 September 1944:
Departs Yulin.

19 September 1944:
Arrives at Saigon.

23 September 1944:
Departs Saigon escorting a convoy.

25 September 1944:
Arrives at Camranh Bay.

28 September 1944:
Departs Camranh Bay on an anti submarine sweep.

29 September 1944:
Arrives back at Camranh Bay.

3 October 1944:
Departs Camranh Bay on a further anti submarine sweep.

5 October 1944:
Returns to Camranh Bay.

6 October 1944:
Departs Camranh Bay and escorts a convoy and carries out an anti submarine sweep.

16 October 1944:
Arrives at Qui Sande anchorage.

17 October 1944:
Departs Qui Sande anchorage escorting a convoy.

19 October 1944:
Arrives at Cana anchorage.

22 October 1944:
Departs Cana escorting a convoy.

24 October 1944:
Arrives at Saigon.

28 October 1944:
Departs Saigon and arrives at St Jacques.

29 October 1944:
CH-43 departs St Jacques with kaibokan CD-20 and stores ship KURASAKI escorting convoy SATA-01 consisting of FUKUJU MARU and two unidentified merchant ships.

3 November 1944:
Arrives at Yulin. KURASAKI is detached.

4 November 1944:
CH-43 departs Yulin. Two unidentified merchant ships join the convoy together with kaibokan CD-34, auxiliary netlayer KAINAN MARU and auxiliary subchaser KASUGA MARU.

9 November 1944:
CH-43 arrives at Takao.

12 November 1944:
Some of the convoy arrives at Keelung, Formosa. At 1800, CH-43 departs Takao with minesweeper W-38, patrol boats PB-38 and PB-102, auxiliary subchaser SHOWA MARU No. 2 and an unidentified warship escorting convoy TAMA-31B consisting of MANJU MARU, five Navy LSTs (including T-159) and an Army LST. MANJU MARU is carrying elements of Lt Yamazaki’s 7th Shinyo Squadron.

15 November 1944:
Anchors off west coast of Formosa.

16 November 1944: SHOWA MARU No. 2 and KOCHI MARU are detached. At 1428 arrives at Sabtang Island.

17 November 1944: At 0628 departs Sabtang Island.

18 November 1944: At 0006 arrives at Musa Bay and departs at 0629. At 1623 arrives at Currimao.

19 November 1944:
At 0157 departs Currimao and at 0440, arrives at Santiago Island Strait. Later that evening, TAMA 31B is attacked by 27 Grummans that inflict slight damage.

20 November 1944:
At 1030, departs Santiago Island Strait.

21 November 1944:
At 1500, arrives Manila.

28 November 1944:
LtCdr Carl Tiedeman's (USNA ’33) USS GUAVINA (SS-362) attacks the convoy at 12-54N, 109-21E without success, but eludes counterattacks by CH-43.

At 1549, USN codebreakers intercept a message from CH-43 that says: “Four torpedoes fired at us at 1549 in position 12-54 N., 109-20 E. We attacked immediately --- ---. Dropped 6 depth charges in the vicinity with unknown results. No damage to convoy.”

E 30 November 1944:
CH-43 arrives at Saigon and is docked for repairs during much of December.

23 December 1943:
CH-43 departs Saigon and undertakes an anti submarine sweep and then escorts a convoy.

28 December 1944:
South China Sea, off Cape Varella, Indochina. CH-43 is escorting a convoy from Hainan Island to Saigon consisting of ex-fleet supply ship NOZAKI and CHEFOO MARU when the convoy is attacked by LtCdr Otis R. Cole’s (USNA ’36) USS DACE (SS-247). Cole torpedoes and sinks NOZAKI 50 miles NE of Nha Trang. USS DACE also damages CHEFOO MARU at 12-36N, 109-38E.

Also on that day, FRUMEL provides the following information:
"Subchaser 43 was ordered at 1731 on 28th to locate and sink the submarine which carried out an attack at 1400 in 12.36N, 109.28E."

29 December 1944:
Off Camranh Bay, Indochina. Destroyers KAYA, SUGI and KASHI find and rescue 25 NOZAKI survivors.

12 January 1945:
South China Sea. Off Camranh Bay. Carrier aircraft of Vice Admiral (Admiral posthumously) John S. McCain's (USNA ’06) Task Force 38 attack and sink CH-43.

3 May 1947:
Removed from the Navy List.

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Authors' Note:
[1] In July 2006, the Russian dive team “Iskra” located and photographed wreckage of USS WAHOO lying in about 213 feet (65 meters) of water in the La Perouse (Soya) Strait between the Japanese island of Hokkaido and the Russian island of Sakhalin.

Thanks go to John Whitman for info on USN intercepts of IJN messages and to Mr. Gilbert Casse of France for general assistance. Special thanks go to Hans Mcilveen of the Netherlands for info on FRUMEL intercepts.

-Bob Hackett, Sander Kingsepp and Peter Cundall.

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