IJN Subchaser CH-20:
Tabular Record of Movement

© 2005-2018 Bob Hackett, Sander Kingsepp and Peter Cundall

Revision 10

Okajima. Laid down at Tama Shipbuilding's yard.

15 May 1941:
Nimbered CH-20. Tentatively attached to Kure Naval District.

29 May 1941:

20 August 1941:
Completed and registered in the Kure Naval District.

8 December 1941:
Assigned to the Kure Guard Unit. Conducts patrols in the Bungo Straits.

February 1942:
Reassigned to the 1st Base Force. Conducts patrols from Staring Bay, Celebes.

7 February 1942:
At 1100 CH-19, CH-20 and CH-21 depart Kure.

8 February 1942:
At 1725 arrives at Amami Oshima.

9 February 1942:
At 1642 all three escorts depart Amami Oshima.

13 February 1942:
At 1500 all three ships arrive at Davao.

15 February 1942:
At 1700 CH-19, CH-20 and CH-21 depart Davao.

19 February 1942:
Arrives at Staring Bay.

23 February 1942:
At 1200 departs Staring Bay.

26 February 1942:
At 1000 arrives at Davao.

27 February 1942:
At 1200 departs Davao.

10 March 1942:
Macassar, Celebes (now Sulawasei). Reassigned to the 2nd Southern Expeditionary Fleet in Captain (later Vice Admiral)(40) (former XO of ATAGO) Mori Kunizo's 23rd Special Base Force with CH-19 and CH-21. Escorts convoys.

8-16 May 1942: Operation "S" – The Seizure of the Lesser Sunda's:
CH-20 departs Surabaya escorting seaplane tender SANYO MARU that begins air support of a combined Army/Navy Operation to "sanitize" an area that includes Lombok, Sumbawa, Flores and the Bali Islands. No resistance by the Dutch is encountered.

9 May 1942:
At 1200 arrives in the Alas Strait.

10 May 1942:
At 1200 departs the Alas Straits.

11 May 1942:
Arrives at Teluk Sape.

21 May 1942:
At 1900 departs Teluk Sape still escorting SANYO MARU.

23 May 1942:
At 1328 arrives at Surabaya.

13 June 1942:
At 1429 11 Ri West of San Pedro Point, Luzon, CH-20 sights and launches a depth charge attack on an enemy submarine. At 1944 17 Ri 269 degrees off Corregidor lighthouse, CH-20 launches a further depth charge attack on an enemy submarine. [presumably USS SEAWOLF]

22 June 1942:
Off Lingayen Gulf meets auxiliary transports RAKUTO and NICHIYU MARUs escorted by auxiliary netlayer KOREI MARU and auxiliary gunboat KISO MARU.

23 June 1942:
At 0000 at 16-05N 119-26E auxiliary netlayer KOREI MARU and auxiliary gunboat KISO MARU are detached.

24 June 1942:
Arrives at Manila.

1 November 1942:
Departs Manila escorting Y convoy consisting of BOSTON, SANKO, HOKKO and FUSHIMI MARUs.

5 November 1942:
Arrives at Guam.

12 November 1942:
Arrives at Palau.

8 December 1942:
CH-2 departs Surabaya with minesweeper W-11 and auxiliary gunboat OKUYO MARU escorting the Oki convoy consisting of an unidentified number of merchant ships.

13 December 1942:
Minesweeper W-11 is detached.

14 December 1942:
Subchaser CH-2 is detached.

15 December 1942:
Subchaser CH-20 joins convoy in the Palau area.

18 December 1942:
Subchaser CH-18 joins convoy and CH-20 is detached.

22 December 1942:
An unknown submarine attacks the convoy. OKUYO MARU drops three depth charges. Later that day the convoy arrives at Rabaul.

13 January 1943:
CH-20 departs Palau with auxiliary subchasers SHOWA MARU and GANJITSU MARU No. 1 escorting a convoy consisting of SHIRAHA, KENZAN, HOEISAN and GENOA MARUs.

14 January 1943:
At 1150, auxiliary subchaser GANJITSU MARU No. 1 and cargo ship SHIRAHA MARU are torpedoed and sunk by LtCdr (later Rear Admiral-Ret) Hiram Cassedy's (USNA ’31) USS SEARAVEN (SS-196) at 09-32N, 130-42E. When sunk the ship was carrying 137 passengers of whom 16, as well as three gunners and eight of the crew – a total of 27 were killed.

18 January 1943:
Arrives at Manila.

2 February 1943:
Arrives at Palau.

3 February 1943:
Departs Palau.

6 February 1943:
Arrives at Palau.

18 February 1943:
Departs Palau.

22 February 1943:
Arrives at Palau.

23 February 1943:
Departs Palau.

1 April 1943:
At 0600 departs Palau to undertake an escort mission mission.

5 April 1943:
At 1730 arrives back at Palau.

8 April 1943:
At 0835 departs Palau on an escort mission.

11 April 1943:
At 2350 arrives at Truk.

13 April 1943:
At 1800 departs Truk on an anti submarine sweep.

15 April 1943:
At 1515 arrives back at Truk.

17 April 1943:
At 1200, departs Truk via the south channel escorting a convoy.

19 April 1943:
At 0820 arrives at Mereyon.

20 April 1943:
Departs Mereyon.

21 April 1943:
Arrives at Palau.

23 April 1943:
Departs Palau.

27 April 1943:
Arrives at Balikpapan.

5 May 1943:
Arrives at Singapore and drydocked.

17 May 1943:

20 May 1943:
Departs Singapore.

13 July 1943:
Departs Singapore.

16 July 1943:
Arrives at Sabang.

18 July 1943:
Departs Sabang.

17 August 1943:
Malacca Straits. CH-20 joins transport NANKAI MARU that is returning from Car Nicobar Island. [1]

18 August 1943:
Arrives at Singapore's commercial port.

7 November 1943:
At 1200 CH-20 departs Penang Island and arrives in her designated anti-submarine sweep area at 1330.

9 November 1943:
CH-20 conducts an anti-submarine sweep in the vicinity of Penang. At 1516, CH-20 drops seven depth charges on a submarine contact for obscure results.

14 November 1943:
At 0400, CH-20 heads for the Bandan Island, west of Penang. At 0605, CH-20 discovers a surfaced enemy submarine at 56 degrees, 10 miles from Jarak Island. She advances towards it. When the range is down to 4000 metres, British submarine HMS TAURUS submerges. At 0630, CH-20 drops two depth charges. At 0812, after regaining contact, another 8 DCs are dropped.

At about 0852, HMS TAURUS resurfaces. Two minutes later a gun duel breaks out. One of CH-20's 8 cm. main gun shells is alleged to have hits the lower part of the submarine's conning tower, but this is doubtful. HMS TAURUS replies with her 10 cm. gun. One shell strikes CH-20's bridge killing her captain Lt Kobayashi Naokazu, and many others. Her chief engineer, Lt(jg) Okuma Yoshimichi takes command. Other shells cause extensive damage to her hull. HMS TAURUS goes under again. Despite her damage, CH-20 drops three more depth charges. HMS TAURUS escapes, but CH-20 claims a sinking.

Soon after, CH-20 becomes immobile with flooding in her engine room and auxiliary machinery room. Shell damage is suffered to her hull. Her casualties are three officers, nine petty officers, seven other ranks KIA; one petty officer fatally wounded; six petty officers and 11 other ranks wounded. Afterward, CH-20 is towed by CHOKO MARU (889 grt) to the Howard anchorage where temporary repairs are undertaken.

15 November 1943:
An unidentified ship listed as RAITO MARU arrives to assist.

16 November 1943:
RAITO MARU attempts to tow CH-20 with CHOKO MARU (889 grt) providing escort; however, troubles arise.

17 November 1943:
3,712 ton freighter HOKUAN MARU is summoned to assist.

21 November 1943:
At 1130, CH-20 towed by RAITO MARU and escorted by CHOKO MARU (889 grt) departs the Howard anchorage. At 2020, they are joined by HOKUAN MARU, but there are more problems, so they return.

22 November 1943:
At 0800, the group finally departs the Howard anchorage. At 1200, they arrive in the (K) Curan Strait. CH-20 undergoes more temporary repairs.

24 November 1943:
In the morning, departs the anchorage.

25 November 1943:
At 1950, CH-20 drops anchor outside Singapore Harbour.

26 November 1943:
At 1755, CH-20 enters the anchorage at Seletar Naval Base. Singapore and begins extensive battle-damage repairs by the IJN’s 101st Repair Unit.

Mid-May 1944:
The repairs are completed.

16 and 19 May 1944:
CH-20 carries out running trials and returns to Singapore each day.

5 June 1944:
CH-20 left Singapore, carried out calibration tests, then returns.

7 June 1944:
CH-20 departs Singapore arriving at Batbhat the same day.

1 August 1944:
Reassigned to the Southwest Area Fleet’s Third Southern Expeditionary Fleet's 21st Subchaser Division with CH-19 and CH-21. Thereafter, escorts convoys to Palau.

17 August 1944 :
CH-20 departs Singapore with kaibokan CD-14 escorting convoy SHIMI-09 consisting of JUZAN MARU and three unidentified merchant ships.

21 August 1944:
Arrives at Kuching to shelter after a torpedo attack on convoy MISHI-07.

24 August 1944:
Departs Kuching.

25 August 1944:
Arrives at Miri.

29 August 1944:
At 0830, CH-20 departs Miri, Borneo with CD-14 and patrol boat PB-38 escorting convoy MI-14 consisting of KENSEI, IIDA, JUZAN, CHUKA and SURAKARUTA MARUs and oilers ATAGAO, OGURA MARU No. 2 and TOKUWA MARUs.

5 September 1944:
Arrives at Manila. The convoy is reformed to consist of TOKUSHIMA, ENOSHIMA, MIHO, KENSEI, KEISHU MARUs and oilers ATAGO, OGURA MARU No. 2, and TOKUWA MARU with the same escorts.

9 September 1944:
At 1600, departs Manila. En route north joins minesweepers W-38 and W-39.

10 September 1944:
Manila. CH-20 is reassigned to the Southwest Area Fleet’s Third Southern Expeditionary Fleet's 31st Special Base Force.

16 September 1944:
At 0440, departs Basco Bay, Batan Island, Philippines. At 1355, TOKUSHIMA MARU is torpedoed and sunk at 21-57N, 121-35E. The ship was loaded with 5400 tons chrome ore, 112 passengers and 20 urns of the war dead. 82 passengers, one communications officer, 44 gunners and 52 of crewmen are KIA. The explosion damages nearby oiler OGURA MARU No. 2. She stops for repairs, but at 1515, OGURA MARU No. 2 is torpedoed and sunk by LtCdr (later Rear Admiral-Ret) Louis D. McGregor's (USNA ’30) USS REDFISH (SS-395) at 21-42N, 121-41E. The ship is loaded with 12220 tons of fuel oil and about 150 crew and soldiers. 23 passengers, 3 Armed Guards and 15 crew are killed.

17 September 1944:
Arrives at Takao, Formosa. CH-20 is detached from the convoy.

18 September 1944:
At 0630, CH-20 departs Takao for Manila with CH-41 and CH-63 and minesweepers W-17 and W-20 escorting convoy TAMA-26 consisting of MIZUHO, SHIRANESAN, EIMAN, ARABIA, TOSHIKAWA, HOTEN, AWAJI and NICHINAN (1945 grt) MARUs and TOYO MARU No. 3.

21 September 1944:
At 0300, the convoy departs Musa Bay. HOTEN MARU has engine trouble and remains at Musa Bay. At 0700, a Japanese aircraft flies to a position forward of the convoy from which it dive-bombs a submarine. At 0705, Cdr (later Vice Admiral) Glynn R. Donaho's (USNA ’27) USS PICUDA (SS-382) torpedoes and sinks AWAJI MARU carrying 500 tons of ammunition, 600 passengers in addition of her 67 crew, at 18-43N, 120-53E. 284 passengers, 3 escort troops and 40 crewmen, a total of 327 people are killed. NICHINAN MARU rescues 82 survivors. At 0835, Cdr Louis D. McGregor's USS REDFISH (SS-395) torpedoes and sinks MIZUHO MARU at 18-37N, 120-41E. 81 crewmen, three gunners and 1,313 passengers of the 5,415 persons she was carrying are lost with her. Also lost are horses, baggage, equipment and ammunition. W-17 counterattacks while the other vessels pick up survivors. CH-20 rescues 622 survivors, CH-63 rescues 150 men, W-20 rescues 370 men, TOYO MARU No. 3 rescues 980, tug/rescue vessel KEISHU MARU (ex British HENRY KESWICK) rescues 1630 men and motorized sailboats BANGI and SAROMAGE rescue 268 survivors. At 2215, the convoy arrives at Lapoc Bay.

26 September 1944:
At 1645, arrives at North San Fernando.

1 October 1944:
At 2056, arrives at Manila. 20 October 1944:
At 2340, CH-20 departs Manila for Takao with destroyers HARUKAZE, TAKE and KURETAKE and fleet supply ship KURASAKI escorting convoy MATA-30 consisting of KOKURYU, KIMIKAWA, KIKUSUI, FUYUKAWA, TENSHIN, SHIKISAN, EIKO, ARISAN, RYOFU and DAITEN MARUs and SHINSEI MARU No. 1.

23 October 1944:
South China Sea, WNW of Cape Bojeador, Luzon, Philippines. About 1730 (JST), Cdr Alan B. Banister’s (USNA ’28) USS SAWFISH (SS-276) attacks ex-seaplane tender KIMIKAWA MARU. She is hit by four of five torpedoes and sinks at 18-58N, 118-46E. Loaded with 300 passengers, bauxite, fuel oil, aviation gasoline and other similar items, the ship takes down 24 crewmen and 81 passengers.

24 October 1944:
The convoy comes under a combined wolfpack attack by five submarines. At 0050, SHINSEI MARU No. 1 is damaged by a dud torpedo at 19-32N, 118-37E. At 0100, KOKURYU MARU is torpedoed and sunk at 19-42N, 118-38E, likely by LtCdr George H. Browne's (USNA ’34) USS SNOOK (SS-279) or LtCdr Richard W. Peterson's (USNA ’31) USS ICEFISH (SS-367). Of 1357 passengers on board 357 of them together with five gunners and 63 crewmen are killed. At 0315, KIKUSUI MARU (ex Dutxh tanker IRIS) is torpedoed and sunk by USS SNOOK at 19-46N, 118-30E. 12 crewmen are KIA.

At 0605 TENSHIN MARU is torpedoed twice and sunk by either USS SNOOK or LtCdr Edward N. Blakely's (USNA ’34) (later KIA) USS SHARK (SS-314) or both, at 19-54N 119-00E. The ship was loaded with 6250 tons of bauxite and five escort troops and 47 crewmen are KIA.

At 0758, SHIKISAN MARU is torpedoed by LtCdr (later Rear Admiral) Maurice H. Rindskopf's (USNA ’38) USS DRUM (SS-228) and sinks in 90 seconds at 20-27N, 118-31E. The ship is time loaded with 1500 tons mixed goods, 3000 tons crude rubber and 3300 tons of manganese. 11 crew and four others die in the sinking. Soon after, DAITEN MARU, sailing in ballast, is also torpedoed and sunk by LtCdr James H. Ashley's (USNA ’34) USS SEADRAGON (SS-194) at 20-12N, 119-01E. Five crewmen are killed.

At 1225, straggling SHINSEI MARU No. 1, loaded with bauxite, is torpedoed by USS SNOOK and sinks in three minutes at 20-31N, 118-42E. Three gunners and 10 of crewmen are killed in the sinking. At 1405, EIKO MARU is torpedoed by SEADRAGON and sinks at 20-35N 118-32E. The ship had rescued about 100 survivors from SHINSEI MARU No.1 and many of these men die, with one crewman from EIKO MARU being killed.

Finally, at 1730, ARISAN MARU is torpedoed and sunk, probably by Blakely's USS SHARK (sunk soon after by HARUKAZE and TAKE) at 20-00N, 118-44E. This IJA transport is carrying 1782 POWs. Only nine of them survive the sinking. 2 crewmen, 13 gunners and 27 other passengers are KIA.

26 October 1944:
At 0715, arrives at Takao.

12 November 1944:
Arrives at Santa Cruz harbor.

15 November 1944:
Departs Santa Cruz for Manila.

28 November 1944: Operation "TA No. 7" - The Reinforcement of Leyte, Philippines:
At 1350, the first of the movement's three echelons, consisting of IJA landing ships SS-5, SS-11 and SS-12, escorted by CH-20, departs Manila.

29 November 1944:
Masbate Island, Philippines. The first echelon lays over, but landing ship SS-5 goes hard aground and is lost to the operation.

30 November 1944:
S of Ormoc, Philippines. Arrives at Ipil at 2300. The SS-landing ships unload food, ammunition, medical supplies and about 200 men. CH-20 picks up 72 survivors of destroyer NAGANAMI bombed and sunk during TA No. 3. That afternoon, while sheltering at Cebu, 30 planes attack the small convoy, but are driven off by IJN fighters and anti-aircraft fire. None of the SS ships is damaged.

1 December 1944:
At 0140, the unloading is completed. The convoy departs in the early morning covered by bad weather.

2 December 1944:
Arrives at Manila at 1530.

January 1945:
Saigon, Indochina. Reassigned to the 11th Base Force for a second time. Escorts convoys to Saigon.

22 January 1945:
At 0700, CH-20 departs Singapore with CH-35, and patrol boat PB-104 escorting convoy HI-88-B consisting of DAIETSU, ENKI and TATSUTAMA MARUs.

27 January 1945:
At 2230 arrives at St Jacques, Indochina. TATSUTAMA MARU and CH-35 are detached. Kaibokan NOMI and CD-60 joins.

28 January 1945:
At 2110, departs St Jacques.

29 January 1945:
At 2230, arrives Van Phong, Indochina.

30 January 1945:
At 0700, departs Van Phong.

31 January 1945:
After two submarine sightings, at 0551, DAIETSU MARU and one minute later, ENKI MARU are torpedoed by Cdr Royce L. Gross' (USNA ’30) USS BOARFISH (SS-327) at 14-56N, 109-00E. ENKI MARU, loaded with 7000 tons of fuel oil, and 1600 tons crude rubber, tin, mail and other goods together with 21 passengers goes down with one escort trooper KIA. DAIETSU MARU, carrying about 8000 tons fuel oil, 570 tons tin and 1200 tons rubber is run aground on the coast to prevent sinking. Two escort troops and seven crewmen are killed. Later, the wreck is bombed.

7 February 1945:
At 0800 departs Cana, Padaran Bay escorting tanker KYOEI MARU No. 3 to Qui Nhon.

8 February 1945:
Arrives at Qui Nhon.

14 February 1945:
At 0800, CH-20 departs Singapore with CH-34, CH-35 and kaibokan CD-31 escorting convoy HI-88-G consisting of YAEI (IYASAKA) MARU No. 1, TAKASAGO MARU No. 2 and NANSHIN MARU No. 30.

21 February 1945:
At 0900, arrives St Jacques, Indochina. NANSHIN MARU No. 30 is detached and probably CH-34.

22 February 1945:
The convoy departs St Jacques.

23 February 1945:
Off Cape Padaran, Indochina. Fifth Air Force B-25 "Mitchell" medium-bombers of the 345th Bomb Group's 500th Bomb Squadron attack convoy HI-88-G. The B-25's come under attack by covering IJA and IJN fighters, including a "Rufe" float fighter. At 1714, the B-25's strafe, bomb and sink CH-35 and damage CH-20 and small oiler NANSHIN MARU No. 30 at 10-15N, 107-31E. One of the B-25's is shot down by a subchaser.

25 February 1945:
Convoy HI-88-G arrives at Tourane, Indochina and merges with convoy HI-88-H. The convoy now consists of HONAN MARU and oilers EISHO MARU, YAEI MARU No. 1 and TAKASAGO MARU No. 2 escorted by CH-20, and CH-57, kaibokans CD-13 and CD-31. Later that day CD-31 departs on a submarine sweep.

27 February 1945:
Early that morning CD-31 arrives at Tourane. At 0800, departs Tourane.

28 February 1945:
At 1600, arrives at Yulin, Hainan Island, China.

1 March 1945:
At 1100, departs Yulin. At 2300, the convoy is attacked by a single large bomber. At 2314, EISHO MARU is bombed and sunk at 18-32N, 108-16E. 99 passengers. Seven crew and 29 others on board are killed and the 4500 ton petroleum cargo is lost.

2 March 1945:
Arrives at Linkao Bay, Hainan Island.

3 March 1945:
At 0115, while still in Linkao Bay preparing to leave, three aircraft attack. YAEI MARU No. 1 is bombed and sunk at 20-10N, 109-31E. Two of 21 passengers, two gunners and 27 crewmen are killed.

5 March 1945:
CH-20 is reassigned to the General Escort Command’s First Escort Fleet’s 31st Subchaser Division with CH-19, CH-21, CH-26 and CH-60.

At an unknown point CH-20 is later detached from HI-88H.

17 March 1945:
Arrives at St Jacques.

19 March 1945:
CH-20 departs Cape St. Jacques with CH-33, cable-layer TATEISHI, auxiliary subchaser KAINAN MARU and subchaser CH-9 escorting convoy HI-88-I now consisting of HOSEN MARU, FUSHIMI MARU No. 2, GENZAN (MOTOYAMA) MARU No. 1, NANSHIN MARU No. 21 and TAKASAGO MARU No. 6.

20 March 1945:
50 miles S of Camranh Bay, Indochina. At about 0100, convoy HI-88J is attacked by LtCdr Benjamin C Jarvis' (USNA ’39) USS BAYA (SS-318). Jarvis torpedoes and sinks KAINAN MARU with unknown casualties. CH-9 counterattacks BAYA and drops 21 DCs .

That same afternoon, at about 1720, the convoy is attacked by LtCdr (later Cdr) William H. Hazzard's (USNA ’35) USS BLENNY (SS-324). Hazzard torpedoes and sinks small oilers NANSHIN MARU No. 21 carrying 140 tons oil products with the loss of 14 crewmen, and HOSEN MARU, loaded with gasoline with the loss of 170 passengers, eight Gunners and 18 crewmen.

21 March 1945:
Off Nha Trang, Indochina. At about 1120, convoy HI-88-I is attacked by Fifth Air Force B-25 "Mitchell" medium-bombers of the 345th Bomb Group that sink CH-33, cargo vessels MOTOYAMA MARU No. 1 and FUSHIMI MARU No. 2. MOTOYAMA MARU No. 1, also sometimes called GENZAN MARU No. 1 sinks with the loss of four crewmen; FUSHIMI MARU No. 2 carrying an estimated 1200 tons of petroleum sinks with three crewmen and 11 others KIA. The B-25's also damage CH-9, small oiler TAKASAGO MARU NO. 6 and cable-layer TATEISHI. Damaged CH-9 and CH-20 take refuge at Nha Trang.

One B-25 is lost. Four crewmembers are captured. One dies of injuries. Later, the Japanese decapitate the other three crewmen.

At 1120 ,USN codebreakers intercept and decrypt a message from CH-33 that reads: “Engaging 15 B-25s. CH-33 and No. 2 FUSHIMI MARU sank.”

Codebreakers decrypt another message that reads: “At 1100 in position 12-03N, 109-00E convoy HI-88I . . .” CH-33 sunk and “CH-9 is to ---anchor off Natoran at 1200----. Killed in battle: Captain and 7 others. Wounded: 222 men.” A later Japanese report amends the location of this attack to 12-30.7N., 109-14.3E.

25 March 1945:
At 2200 CH-20 arrives at St Jacques.

26 March 1945:
CH-20 departs St Jacques escorting HI-88J consisting of HONAN, KAIKO, ASOKAWA, SARAWAK MARUs escorted by destroyer AMATSUKAZE and kaibokan CD-18, CD-84, CD-130 and CD-134. During the day CD-26 meets up with the convoy from Yulin.

27 March 1945:
At 2000 arrives at Nha Trang Bay. Convoy HI-88I is absorbed into a new convoy called HI-88J. Additional escorts are added. HI-88J now consists of tankers HONAN, ASOKAWA, KAIKO MARUs and probably NANSHIN MARU No. 30 escorted by kaibokan MANJU, CD-18, CD-26, CD-84, CD-130, CD-134, CD-1, destroyer AMATSUKAZE (with a temporary bow fitted) and subchasers CH-20 and probably CH-9.

28 March 1945:
At 0800, departs Nha Trang Bay. At 1040, an air attack begins and ASOKAWA MARU is hit in the engine room and sinks. 92 passengers, eight gunners and 34 crewmen are KIA. MANJU and CD-84 rescue survivors. At 1220, LtCdr (later Captain) Eric L. Barr's (USNA ’34) USS BLUEGILL (SS-242) torpedoes HONAN MARU. Her captain runs her aground and she is lost. Five Gunners and 44 crewmen are KIA. NANSHIN MARU No. 30 probably is detached.

29 March 1945:
At 0710, LtCdr Frank M. Smith's (USNA ’35) USS HAMMERHEAD (SS-364) torpedoes and sinks CD-84 at 14-40N, 109-16E. MANJU rescues some survivors. At 1130, another submarine attack coincides with an air attack and KAIKO MARU is bombed and sunk. 22 passengers, four Gunners and 19 crewmen are KIA. At 2230, a further air attack damages CD-134.

30 March 1945:
At 1000, the escorts, now without a convoy, arrive at Samah. Air attacks persist and at 1045, CD-26 is damaged by a bomb hit. The destruction of this convoy marks the end of the Singapore-Empire convoys.

31 March 1945:
At 1300 departs Samah.

4 April 1945:
At 1700, CH-20 departs Hong Kong with CH-9, destroyer AMATSUKAZE, kaibokan CD-1 and CD-134 en route to Shanghai escorting convoy HOMO-03 consisting of TOKAI MARU No. 2 and KINE MARU.

5 April 1945:
Pinghai Bay, China. USN Martin PBM-5 "Mariner" maritime patrol flying boats attack convoy HOMO-03 and sink TOKAI MARU No. 2 at 22-24N, 116-10E. 16 gunners and 13 crewmen are KIA. Later, 5th Air Force B-24 "Liberators", B-26 "Marauders" and P-38 "Lightnings" attack the convoy and sink KINE MARU at 22-24N, 115-28E. 56 passengers, five gunners and 19 crewmen are killed. The convoy is dissolved. CH-9 and CH-20 return to Hong Kong.

Hong Kong. That same day, Far East Air Force B-24s bomb and damage CH-9, CH-20, fleet oiler KAMOI and kaibokan CD-1 and CD-52 at 22-45N, 116-10E.

6 April 1945:
At 1835, USN codebreakers intercept and decrypt a message from CH-20 that reads: “Because of not being able to proceed northward on account of bad weather and it being inappropriate to remain at this anchorage with survivors aboard, we departed (Nanmangtao ?) at 1800 and headed for Hong Kong. Scheduled to arrive at 1000, 7th.”

7 April 1945:
Arrives at Hong Kong.

26 April 1945:
Coast of China. At 0755, CH-20 departs the Shusan Sea area for Moji with destroyer ASAGAO, kaibokan UKU and CD-25, patrol boat PB-102 (ex-USS STEWART, DD-224) and minesweeper W-29 escorting convoy SHIMO-03 consisting of KASHIMA, BANSHU, ABUKUMAGAWA, SHINTON and TAIKYU MARUs and NANRYU MARU No. 9.

27 April 1945:
Convoy SHIMO-03 is attacked by aircraft and unidentified submarine(s). The planes make many attacks and bomb and strafe the convoy. UKU and patrol boat PB-102 are damaged at 34-52N, 124-23E.

28 April 1945:
At 1200, arrives at Moji.

15 August 1945:
Kure. While CH-20 is undergoing repairs and maintenance, her crew is notified of the termination of hostilities with the Allied Powers.

4 May 1948:
Begins scrapping at the Kawaminami shipyard.

Authors’ Notes:
[1] It is unclear whether kaibokan SHIMUSHU that escorted NANKAI MARU to Car Nicobar is still an escort, but given size and value of ship this appears likely.

Thanks go to John Whitman of the USA for info on CNO intercepts of Japanese messages. Thanks also go to Bill Somerville for info concerning CH-20's encounter with HMS TAURUS and subsequent events, and to Mr. Gilbert Casse of France for reviewing Revision 5.

-Bob Hackett, Sander Kingsepp and Peter Cundall.

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