© 1999 Anthony P. Tully (revised 2007)
1 July 1942:
Conversion from NITTA MARU to an escort carrier begun at Kure, with Captain Okura Tomasaborou assigned as fitting-out officer.
25 November 1942:
Conversion to an escort carrier completed at Kure, named CHUYO and assigned to Combined Fleet. Captain Tomasaborou remains as commanding officer.
28 November 1942:
Arrive at Yokosuka, and enter drydock.
4 December 1942:
12 December 1942:
Depart Yokosuka for Truk on the first of thirteen voyages ferrying planes, supplies, and passengers. Note: almost invariably the screen was the "workhorses" of Desdiv 7, the AKEBONO, SAZANAMI, and USHIO. When others are present, they are mentioned.
18 December 1942:
Arrive at Truk; Depart 21 December back for Yokosuka.
26 December 1942:
Return to Yokosuka.
2 January 1943:
8 January 1943:
Arrive at Truk, escorted by SHIGURE and ASAGUMO.
10 January 1943:
12 February 1943:
Arrive at Truk; 15th depart.
20 February 1943:
Arrive at Yokosuka.
28 February 1943:
Depart Yokosuka for Truk.
5 March 1943:
Arrive at Truk, departs on the 8th.
13 March 1943:
Returns to Yokosuka and remains there till the end of the month.
4 April 1943:
Depart Yokosuka with TAIYO and CHOKAI for Truk, escorted by HIBIKI, KUROSHIO, and SAZANAMI.
7 April 1943:
Stopover at Saipan; depart same day.
9 April 1943:
Late evening: Approaching Truk, the task force is attacked by USS TUNNY. But her torpedoes malfunction, inflicting merely dents on TAIYO.
10 April 1943:
Arrive with TAIYO and CHOKAI at Truk.
16 April 1943:
Depart Truk with TAIYO escorted by SHIGURE and HIBIKI for Yokosuka.
17 April 1943:
Stopover at Saipan; joined by SAZANAMI, depart the same day.
21 April 1943:
Arrive at Yokosuka, depart again with UNYO and TAIYO, escorted by NAGANAMI and SHIGURE, for Truk on the 25th, arriving there on the 30th.
8 May 1943:
Depart Truk for Yokosuka.
13 May 1943:
Arrive with UNYO at Yokosuka, both carriers turn around and depart again for Truk on 24 May.
29 May 1943:
Arrive with UNYO at Truk.
5 June 1943:
Depart Truk accompanying UNYO for Yokosuka, arriving on the 9th.
16 June 1943:
Depart Yokosuka with RYUHO and UNYO for Truk.
21 June 1943:
Arrive at Truk, depart to Yokosuka on 28 June, arriving with UNYO 2 July at Yokosuka.
10 July 1943:
Depart Yokosuka for Truk; arriving there on 16 July.
19 July 1943:
Depart Truk with RYUHO and UNYO for the homeland, arriving at Yokosuka on 24 July. A rest is now taken, the ship remaining home through the end of the month.
9 August 1943:
Enter drydock at Yokosuka.
18 August 1943:
7 September 1943:
Voyages resume; depart Yokosuka with TAIYO for Truk. Arriving at Truk on 11 September.
21 September 1943:
Depart Truk with TAIYO for Yokosuka, escorted by SHIMAKAZE.
24 September 1943:
South of Yokosuka, TAIYO is hit by torpedo in starboard quarter from USS CABRILLA. Moderate damage and a loss of a shaft is inflicted, and CHUYO has to take her in tow.
26 September 1943:
Return safely to Yokosuka with the damaged TAIYO.
27 September 1943:
Attached to Combined Fleet.
4 October 1943:
Depart Yokosuka for Truk, arriving on the 10th.
15 October 1943:
Depart Truk; returning to Yokosuka on 20 October.
27 October 1943:
1 November 1943:
Arrive at Truk; depart on the 5th with ZUIHO for Japan.
10 November 1943:
Return with ZUIHO to Yokosuka.
15 November 1943:
Attached to Grand Escort Command.
16 November 1943:
Depart Yokosuka with ZUIHO and UNYO for Truk; arriving there on 21 November.
30 November 1943:
Depart Truk for Yokosuka as part of a task force led by ZUIHO, and comprised also of UNYO and MAYA, and escorted by AKEBONO, SAZANAMI, URAKAZE, and USHIO. Aboard the CHUYO and UNYO are twenty-one and twenty POWs respectively from USS SCULPIN, sunk 19 November by YAMAGUMO.
4 December 1943:
- At 0010, hit by in port bow magazine by torpedo from USS SAILFISH (SS-192) in position: 32-30'N, 143-40'E. Though magazine does not catch fire, the bow plates are torn and the forward part of the flight deck collapses. But the carrier is able to maintain headway, and in order to proceed, Captain Tomasaborou reverses direction and begins to steam backwards towards Yokosuka at half-speed.
- At 0555 is hit again by two torpedoes in the port engine room in a second attack. (Note 1) Ship is stopped dead in the water and unable to navigate - position: 31-55'N, 143-40'E. Destroyer URAKAZE and cruiser MAYA come to assist, and air cover from the homeland arrives overhead at dawn. Despite this aid, --
- At 0842 the ship is again attacked and hit by one or two torpedoes in the port side. Flooding massively, she now quickly rolled to port and plunged by the bow at 0848. As a result, loss of life was very heavy: Captain Tomasaborou and 513 officers and men, and more than 730 passengers went down with the ship. Among the lost twenty of the U.S. POWs from USS SCULPIN. Only one of the POWs survived to be rescued among the mere 160 survivors found by SAZANAMI and URAKAZE. (See Note 2)
5 February 1944:
Removed from Navy List.
First of four Japanese escort carriers to be sunk by U.S. submarines in the Pacific War.
Note 1: It is intriguing to notice that SAILFISH thought her second attack was on the target's starboard side, being unaware that CHUYO was now steaming in reverse!
Note 2: It is unknown whether the figure of 737 passengers reported lost with 513 of CHUYO's crew includes the U.S. PoWs. If the figures do not, the actual number of passengers lost was 757 and the actual saved 161.