Imperial Flattops


IJN Kaiyo: Tabular Record of Movement

© 2006-2007 Anthony Tully, Bob Hackett and Peter Cundall

Revision 2 - Anthony Tully - July 2009

9 December 1938:
Nagasaki. Launched at Mitsubishi’s shipyard and named ARGENTINA MARU.

31 May 1939:
Completed as a 12,755-ton passenger liner for Mitsui's OSK (Osaka Shosen Kaisha) line.

9 December 1942:
OSK sells ARGENTINA MARU to the IJN for an undisclosed amount.

10 December 1942:
Nagasaki. Begins conversion at Mitsubishi’s shipyard to a light carrier. Her diesel engines are replaced by two sets of destroyer turbines.

23 November 1943:
The conversion is completed. Renamed KAIYO ("Sea Hawk") and assigned directly to the Combined Fleet. Captain Takao Yoshimi (43) (former CO of AKITSUSHIMA) is Commanding Officer.

November 1943:
A Type 21 air-search radar is installed. KAIYO undergoes shake-down and workups in the Iyo Nada, Inland Sea.

24 November 1943:
Departs Kure and arrives Kure same day.

3 December 1943:
Departs Kure probably on sea trials within the Inland Sea.

10 December 1943:
Arrives back at Kure. That same day, KAIYO is assigned to the Grand Escort Command, but is used for aircraft transport rather than escort duties.

16 December 1943:
Departs Kure.

18 December 1943:
Returns to Kure.

5 January 1944:
Departs Kure.

7 January 1944:
Arrives at Iwakuni. Probably takes on fuel.

8 January 1944:
Departs Iwakuni and later that day arrives at Nagasaki.

9 January 1944:
Departs Nagasaki and later that day arries Saeki.

10 January 1944:
Departs Saeki but is ordered to return and arrives back at Saeki later that day.

12 January 1944:
Departs Saeki via Manila to Singapore carrying aircraft for the 23rd Air Flotilla escorted by destroyers HIBIKI and INAZUMA.

13 January 1944:
Joins convoy HI-33 consisting of transport AOBASAN MARU and tankers YUHO, TARAKAN, ASASHIO and ASANAGI MARUs and an unidentified ship escorted by kaibokan ETOROFU, minelayer YAEYAMA and subchaser CH-36.

14 January 1944:
At 1930, arrives at Takao.

16 January 1944:
Arrives at Manila.

17 January 1944:
Departs Manila, but develops a steering problem and is forced to return to Manila later that day.

18 January 1944:
Departs Manila.

21 January 1944:
Arrives at Singapore.

31 January 1944:
Departs Singapore in aircraft ferry role. Embarked are twenty-six Type 12 B6N2 "Tenzan" carrier torpedo bombers of the 551st Air Group. (It is worth noting that wings of these aircraft could fold at half-way point; allowing KAIYO to carry such a large number).

3 February 1944:
Arrives at Tarakan. Refuels.

4 February 1944:
Departs Tarakan.

8 February 1944:
Arrives at Palau. Departs that same day for Truk still carrying aircraft for the 551st Air Group.

10 February 1944:
About 2100, LtCdr Carter L. Bennett’s old USS PERMIT (SS-178) makes an unsuccessful night visual attack on the surface at a target PERMIT’s crew take to be a heavy cruiser. Bennett fires four Mark 14 torpedoes at slow-speed at the extreme range of 9,000 yards, but misses KAIYO.

11 February 1944:
Arrives at Truk. (It is worth noting that 18 of the aircraft of 551st offloaded were lost in the TF 58 raid on Truk eight days later.) Later, departs for Kure with HIBIKI and INAZUMA.

13 February 1944:
Departs Truk.

15 February 1944:
Arrives at Saipan and departs later that day.

19 February 1944:
Arrives at Hiroshima Bay.

20 February 1944:
Arrives at Kure.

23 February 1944:
Departs Kure. Arrives at Innoshima that day for repairs at Hitachi Zosen's yard.

2 March 1944:
Repairs are completed. Departs Innoshima.

3 March 1944:
Arrives at Kure.

9 March 1944:
Departs Kure. Undertakes training exercises in the Saeki area.

16 March 1944:
Arrives back at Kure.

17 March 1944:
KAIYO is assigned to Rear Admiral Matsuyama Mitsuhara's First Surface Escort Division.

28 March 1944:
Departs Kure.

1 April 1944:
Departs Moji with kaibokan ETOFORU, IKI, SHIMUSHU, CD-8, CD-9 and torpedo boat SAGI escorting convoy HI-57 consisting of oilers ITSUKUSHIMA, OTOWASAN, RYOEI and OMUROSAN MARUs, troop transports SHINSHU and MAYASAN MARUs and three unidentified ships.

2 April 1944:
The convoy encounters severe weather and returns to Moji.

3 April 1944:
At 0600, the unchanged convoy departs Moji.

7 April 1944:
At 1450, arrives at Takao.

8 April 1944:
At 1000, departs Takao.

12 April 1944:
At 1930 arrives at Camranh Bay.

13 April 1944:
At 1200, departs Camranh Bay.

16 April 1944:
At 1240, arrives at Singapore.

21 April 1944:
At 0700, departs Singapore with kaibokan ETOFORU, IKI, SHIMUSHU, CD-8 and CD-9 escorting convoy HI-58 consisting of oilers ITSUKUSHIMA, RYOEI, OMUROSAN and OTOWASAN MARUs, troop transport SHINSHU MARU, and probably ZUIHO and MAYASAN MARUs.

That same day, one of KAIYO's attack planes sights LtCdr Manning M. Kimmel's (son of former CINCPAC, ADM H. E. Kimmel) USS ROBALO (SS-273) on the surface about 15 miles behind the convoy. The plane drops two bombs on ROBALO and calls for assistance. IKI and CD-9 arrive and drop depth charges. ROBALO is damaged, but escapes.

25 April 1944:
Arrives at Camranh Bay.

29 April 1944:
Arrives at Takao.

2 May 1944:
Arrives and anchors off Fukue.

3 May 1944:
HI-58 arrives at Moji. Later that day, KAIYO arrives at Kure.

24 May 1944:
Departs Kure.

25 May 1944:
Arrives at Moji.

29 May 1944:
At 0600, departs Moji with escort carrier SHINYO, light cruiser KASHII, kaibokan AWAJI, CHIBURI and CD-19, minelayer TSUBAME and subchaser CH-60 escorting convoy HI-65 consisting of oilers SHIRETOKO, ITSUKUSHIMA, OMUROSAN, ZUIHO and TOHO MARUs, cargo liners ARIMASAN, MANILA, KASHII and TATSUWA MARUs and troop transport SHINSHU MARU.

2 June 1944:
Formosa Straits. AWAJI is torpedoed by LtCdr Albert L. Raborn's USS PICUDA (SS-382) and sinks near Yasho Island at 22-48N, 121-24E. Raborn fires two torpedoes at ARIMASAN MARU that cause her to collide with SHINSHU MARU's stern. This causes a depth charge explosion that kills about 70 men and causes rudder damage. KASHII takes SHINSHU MARU in tow. ARIMASAN MARU is lightly damaged in the attack and heads for Kirun with KASHII and SHINSHU MARU. [1]

2 June 1944:
E of Formosa, near Yasho Island. The convoy is attacked unsuccessfully by LtCdr (later Captain) Enrique D. Haskins' new USS GUITARRO (SS-363) enroute from Pearl to Fremantle. One of his torpedoes makes a circular run and GUITARRO is forced deep. Later, GUITARRO avoids depth charge and aircraft attacks and escapes to Australia.

4 June 1944:
Arrives at Takao, Formosa. KAIYO rejoins the convoy after a brief stop at Saei. Oiler JINEI MARU joins the convoy at sea.

8 June 1944:
Off Indochina. At 0906(H), Cdr (later ADM/CINCPAC) John S. McCain’s USS GUNNEL (SS-253) sights KAIYO at 11-59N, 112-29E on base course 205° T, speed 11.5 knots. GUNNEL’s high periscope observations disclose a small aircraft carrier and at least three unidentifed ships. GUNNEL’s SJ radar picks up an aircraft at 24 miles. The Officer of the Deck (OOD) dives prematurely. Contact with the convoy is lost and never regained.

12 June 1944:
At 1350, arrives at Singapore.

17 June 1944:
At 0400, departs Singapore with light cruiser KASHII and kaibokan CHIBURI, CD-7 and CD-11 escorting fast convoy HI-66 consisting of transport/cargo liners SANUKI, HOKKAI and AWA MARUs and tanker OMUROSAN MARU. The convoy hugs the continental coast avoiding deep water as much as possible.

26 June 1944:
At 1300, arrives at Moji.

27 June 1944:
Arrives at Kure.

2 July 1944:
Drydocked in Kure Naval Yard. Twenty Type 96 25-mm AA guns are fitted bringing her AA suite to a total of 44 barrels.

5 July 1944:

9 July 1944:
Departs Kure.

13 July 1944:
At 1600, KAIYO and escort carrier TAIYO each loaded with aircraft, depart Mutsure for Manila in convoy HI-69 escorted by escort carrier SHINYO, light cruiser KASHII and kaibokan CHIBURI, SADO and CD-7 and CD-17. The convoy under Rear Admiral Sato Tsutomu (former ComSubRon 1) of the Eighth Escort Convoy consists of KIMIKAWA, KOEI, AKI, ASAMA, SAIGON, HAKKO MARU, OTOWASAN, OMUROSAN, KUROSHIO, HARIMA, SERIA, KACHIDOKI (ex-PRESIDENT HARRISON), MANKO and TENEI MARUs and probably MANJU MARU. [2]

18 July 1944:
Near Takao, Formosa. About 0600, LtCdr John J. Flachsenhar's USS ROCK (SS-274) fires four torpedoes at HARIMA MARU, but misses. Cdr Alan Banister's USS SAWFISH (USS 276) then fires nine torpedoes at the convoy. HARIMA MARU is hit by a single torpedo, but she is able to steam. At 1055, LtCdr Roger M. Keithy's USS TILEFISH (SS-307) torpedoes and heavily damages CD-17. The convoy continues to Manila without stopping at Takao as originally planned (less MANKO MARU that was detached the day before and damaged HARIMA MARU and CD-17 that put into Takao).

20 July 1944:
Arrives at Manila at 2100. KAIYO and TAIYO are detached and begin unloading aircraft.

24 July 1944:
Captain (Rear Admiral, posthumously) Kitamura Masayuki (45) (former CO of NAGARA) assumes command. At 0400, convoy MATA-01 departs Manila for Takao. The convoy includes KAIYO and transports GOKOKU and ASAMA MARUs escorted by destroyers AKIKAZE, HATSUSHIMA and TSUGA and minesweeper W-28.

27 July 1944:
At 1400, arrives at Takao.

28 July 1944:
Departs Takao. Convoys HI-69 convoy on its return leg from Takao toward Mutsure.

1 August 1944:
Arrives at Kure. Undergoes repairs. Captain Arita Yuzo (48) assumes command.

4 August 1944:
Arrives at Moji to join a convoy, but suffers a machinery breakdown.

25 August 1944:
Arrives at Sasebo.

21 October 1944:
Departs Kure.

22 October 1944:
Arrives at Sasebo.

25 October 1944:
Departs Saesbo for Keelung, Formosa on a special transport of aviation materials with light carrier RYUHO and destroyers HINOKI, MOMI and MOMO. KAIO carries 12 transport aircraft.

27 October 1944:
1000: Arrives at Keelung, Formosa with DesDiv 43.

30 October 1944:
Departs Keelung.

2 November 1944: Arrives at Kure.

22 November 1944:
Departs Kure for Mutsure.

25 November 1944:
At 2000, departs Moji with kaibokan CD-35, CD-64, CD-63 and CD-207 escorting HI-83 consisting of transport/cargo liners SANUKI, ORYOKU and NISSHO MARUs for Manila and tankers KYOKUUN, SEISHIN, HARIMA, TOA and EISHO MARUs for Singapore. Another unidentified ship in the convoy is bound for Takao.

26 November 1944:
Departs Sasebo.

30 November 1944:
At 0600, convoy HI-83 arrives at Takao. The Manila contingent is detached from the convoy. KAIYO stops at nearby Saei.

1 December 1944:
The convoy departs Takao joined by tanker MIRI MARU and patrol boat PB-102 (ex-USS STEWART, DD-224). KAIYO joins the convoy from Saei.

3 December 1944:
KAIYO arrives at Yulin, Hainan Island, China. The convoy is some distance behind.

8 December 1944:
Departs Yulin with the convoy.

9 December 1944:
HI-83 arrives at Quinon, China.

10 December 1944:
KAIYO is reassigned to the First Escort Fleet.

13 December 1944:
HI-83 arrives at Seletar Naval Base, Singapore.

26 December 1944:
At 1158, KAIYO, kaibokan OKINAWA, CD-27 and CD-63, patrol boat PB-102 depart Singapore for Moji escorting convoy HI-84 consisting of oilers TOA and MIRI MARUs, transports AWA MARU, AKASHI MARU, and AMATO MARU. AWA MARU carries about 525 British, American and Australian POWs and 476 passengers.

29 December 1944:
At 1157, HI-84 arrives at Cape St. Jacques (near Saigon) and departs at 1625 the same day.

30 December 1944:
South China Sea. HI-84 passes 2-YB (Second Striking Force) of Fifth Fleet Vice-Admiral Shima Kiyohide flying his flag in HYUGA, with CarDiv 4 (HYUGA, ISE), cruisers OYODO and ASHIGARA, DesDiv 2's ASASHIMO and DesDiv 18's KASUMI that are enroute south from Camranh Bay. Later that day, HI-84 arrives at Binhoang Bay, Indochina.

31 December 1944:
At 0745, HI-84 departs Binhoang Bay. Soon after departure, KAIYO is sighted by LtCdr Otis R. Cole's USS DACE (SS-247). Cole fires three torpedoes at KAIYO, but gets no hits. There is no counterattack, as the convoy seems unaware of the attack. At 1804, HI-84 arrives at Quinhon, Indochina.

1 January 1945:
Arrives at Tourane.

2 January 1945:
Departs Tourane.

5 January 1945:
At 1840, convoy HI-84 arrives at the Hong Kong area and departs at 1937.

9 January 1945:
Arrives at Chusan Retto (archipelago).

10 January 1945:
Departs Chusan Retto.

13 January 1945:
At 1725, arrives at Moji.

14 January 1945:
Arrives at Kure. KAIYO is fully operational. Assigned with light carrier HOSHO, target ship SETTSU and old destroyer YUKAZE to target and aircraft training duties in the Inland Sea.

15 March 1945:
Captain Kofuda Kiyoshi (49) assumes command.

19 March 1945:
Vice Admiral (later Admiral) Marc A. Mitscher's Task Force 58 carriers make the first carrier attack on the Kure Naval Arsenal. More than 240 aircraft (SB2C "Helldivers", F4U "Corsairs" and F6F "Hellcats") attack battleships HYUGA, ISE, YAMATO, HARUNA, carriers AMAGI, KATSURAGI, RYUHO, KAIYO and other ships. KAIYO, moored E of KATSURAGI, is hit by a bomb in the port engine room and set afire. KAIYO is listing to port and flooding appears dangerous; she is moved out of harbor and across to shallow water near Eta-Jima in the afternoon as a precaution.

21 March 1945:
KAIYO returns to Kure harbor.

28 March 1945: Reassigned to the Kure Naval District. Today, with battleship YAMATO and bulk of 2nd Fleet, departs Kure. Camouflage work begins en-route. Returns to Kure a week later.

13 April 1945:
KAIYO under camouflage at Hitonose, Eta-Jima Island near Kure.

20 April 1945:
Kure Naval Yard. Drydocked at No. 3 Dock. Camouflaged in green paint. That same day, KAIYO is "paid off" as a carrier, but "retains her steaming and gun crew for training purposes". She is assigned directly to the Combined Fleet, Fourth Reserve, as a target warship in Beppu Bay for exercises with special attack (suicide) weapons, including kaiten manned-torpedoes. Moves to Hinode (also Hitose), Beppu Bay.

28 April 1945:
Returns to Kure from Hinode for some drydock work.

1 May 1945:
Captain Osuga Shuichi (51)(former CO of HOSHO) assumes command as an additional duty.

5 May 1945:
Major B-29 air raid on Kure Navy Yard. KAIYO is in drydock at the time, and engages with AA. No damage.

20 May 1945:
Once more designated as a training carrier to serve in exercises for pilots out of Oita. At this time her compliment is 73 officers, and 806 men. Departs Kure and later that day arrives off Beppu Wan.

May-July 1945:
Makes regular local sorties to train aviators out of Beppu Bay. She generally follows a elongated loop out to the eastward from Beppu Bay, departing and returning the same day.

28 May 1945:
Photographed at Beppu Bay.

18 July 1945:
1938 hours: While engaged in torpedo exercises with kamikaze planes and kaitens, KAIYO strikes a mine in Sada Straits, Fudai Bay, 135 miles NW of Sata Misaki Lighthouse, Kyushu. The damage is "extremely slight however and offers no hindrance to operations."

24 July 1945:
Massive carrier air strikes by U.S. Task Force 38 and British Task Force 57 on Inland Sea and Kure area. KAIYO departs Beppu Bay earlier than planned to avoid air attack, heading for Muroura. However while maneuvering to avoid air attack in southern Kizuki Bay, KAIYO struck a mine and went dead in the water. Rudder was damaged and some flooding in port engine room; steam pipe broken. Aircraft further damage KAIYO with two hits (possibly rockets) and kaibokans CD-4 and CD-30. Flooding aft is severe and slowly gaining. Destroyer YUKAZE which had departed on 23 July for exercises with Oita Air Base, joins the carrier in the evening. YUKAZE establishes a tow line, and at 2350 the tow gets under way, departing Kizuki Bay for Beppu Bay. [3]

25 July 1945:
0500 hours: Arrive off Hinode - since having difficulty stemming flooding KAIYO is brought close to Hinode shore, "Hiroshita sea coast" in Beppu Bay of Oita Prefecture. At dawn KAIYO is deliberately grounded while emergency pumping continues. Gradually, it is able to keep pace with the flooding. However, since her fresh water condensors fail the crew has to have water brought daily from shore. The crew works to seal the leaks and pump out the ship.

28 July 1945:
KAIYO is attacked by carrier planes, probably from USS ESSEX’s (CV-9) VBF-83. She is hit by either a rocket or bomb in the switchboard room and generators. This kills electricity and power to her generator room and stops her pumps. VBF-83 claims 18 rocket hits. (These apparently hit flight deck on starboard side). Two other hits are reported. Flooding on port side gains, and she bottoms with bow down and a port list. The position is Hiji harbor, Beppu Bay KAIYO at 33-20N, 131-32E. However, losses are minimal with twenty men killed. Damage control teams continue to work, but without ventilation and lighting, the work is very difficult.

29 July 1945:
Hiji harbor, Beppu Bay. Fifth Air Force B-25 "Mitchell" medium bombers damage KAIYO. Later, KAIYO is also attacked by aircraft from USS TICONDEROGA. A medical doctor from shore inspects conditions in the engine room, and urges that the repair crews give up. Without ventilation and power, the conditions are very unhealthy. Captain Osuga concurs, and the salvage effort is abandoned. To fix the vessel more firmly in place and also to preserve them, the boilers are flooded with water and the engine machinery coated with oil. It is hoped this will preserve the ship until a full salvage effort can be made. [4]

9 August 1945:
Beppu Bay.- 0930 KAIYO's hulk is attacked by 12 Fifth Air Force B-25s of the 38th Bomb Group led by Col. Edwin Hugh Hawes. After dropping two bombs on the "left side of the carrier" Col. Hawe's leading B-25 apparently catches a wing tip on KAIYO's camouflage tree limbs and netting, flips over and crashes in the bay. After this attack, the last of the caretaker crew maning AA guns leaves the ship.It now appears that near-misses of exploding bombs did additional damage (See next entry)

10 August 1945:
At 0800 KAIYO begins listing increasingly to port, the side facing the shoreline. By 1246 all of the port side of the flight deck is under water. Captain Osuga orders the ship's flag transferred ashore, and the crew transferred to Yokosuka.[5]

2 September 1945:

20 November 1945:
Removed from the Navy List:

1 September 1946-30 January 1948:
Beppu. Scrapped by Nissan Salvage. The flight deck was dismantled and the boilers and heavy equipment were first lifted out of the hulk. The hull then was refloated and pushed closer to shore for final scrapping. This is mentioned to explain the familiar oft-published yet confusing late 1947 photo of her hull apparently beached.

Tully Note:
[1] Somes sources credit AWAJI's sinking to Haskins' GUITARRO (SS-363).

[2] KAIYO carried 65 Mitsubishi A6M "Zeke" fighters, 55 Yokosuka D4Y "Judy" bombers and 10 transports of unknown type. This large number of aircraft suggests that most, if not all, were carried disassembled, probably in crates.

[3] This towing of KAIYO by destroyer YUKAZE incidentally, is the only Japanese carrier successfully towed to refuge by a destroyer. Japanese praised the action, for KAIYO was "ten times the size" of little YUKAZE, an elderly destroyer, at that. DesDiv 17's ISOKAZE and HAMAKAZE had between them taken torpedoed SHINANO in tow briefly, but had to abandon the attempt.

[4] Some sources use the phrase "capsized and sunk" or just "capsized" for the loss of KAIYO. This is misleading and incorrect. KAIYO never had a list greater than 20 degrees to port, even as a wreck to the time of refloating and salvage of the hull, and can be regarded as "bottomed while upright". (However, new info of spring 2009 shows that for a time the side of KAIYO's flight deck was in water -- this could meet the definition of capsized and explain its use. But she didn't stay that way long. I now believe this examination by the medical doctor likely refers to salvage efforts made after KAIYO was formally abandoned on 10 August. See Note 5.) - Tully

[5] This new bit of data from CNO damage summaries of intercepts post-war, provided courtesy of John Whitman, is important. Though little more than a fragment, it fleshes out the story and affirms that KAIYO remained manned till just after the Fifth Air Force's attack by B-25s. Indeed, shows that the raid played a role in her final total loss. (Col. Hawes posthumously received the Distinguished Flying Cross.) It is worth noting that photos of KAIYO bottomed show the flight deck well clear of the water but with a port list -- as these appear to be in August or later post-war, it seems likely that pumping efforts had raised the hull a bit and the port flight deck edge was no longer in the water as when abandoned. The inspection urging final abandonment of all efforts was probably made after 10 August. - Tully

Thanks to Sander Kingsepp and Hiro Inoue for key translations and John Whitman for radio intelligence data.

- Anthony Tully, Bob Hackett, and Peter Cundall

Initial Posting: 5 October 2006
Revised: 7 May 2007
Last writing: 11 July 2009.

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