(Oiler by Takeshi Yuki scanned from "Color Paintings of Japanese Warships")


Tabular Record of Movement

© 2005-2016 Bob Hackett and Peter Cundall.

Revision 1

24 July 1943:
Nagasaki. Laid down at Mitsubishi as a 10,536-ton Standard Merchant 1TL Tanker for Kokuyo Kisen K.K.

11 November 1943:
Launched and named SEIYO MARU.

15 January 1944:

11 February 1944:
At 1600, SEIYO MARU departs Moji in convoy HI-43 with TOKUSHIMA MARU and five unidentified merchants escorted by kaibokan TSUSHIMA.

16 February 1944:
At 1100, arrives at Kirun (Keelung), Formosa.

18 February 1944:
At 1000, departs Kirun.

23 February 1944:
At 1730, arrives at Camranh Bay, Indochina.

29 February 1944:
At 0900, departs Camranh Bay.

3 March 1944:
At 1700, arrives at Singapore.

11 March 1944:
At 0730, convoy HI-48 departs Singapore consisting of tankers SEIYO, ITSUKUSHIMA, OMUROSAN, OTOWASAN, TATEKAWA, ITSUKUSHIMA, NICHIEI and KUROSHIO MARUs, transport/cargo liners AWA, SANUKI, TEIA and HOKUROKU MARUs and two unidentified ships escorted by kaibokan MIYAKE, SHIMUSHU, IKI and ETOROFU.

19 March 1944:
At 1600, arrives at Takao.

20 March 1944:
At 1300, departs Takao. That same day, SEIYO MARU is officially requisitioned by the IJN and asigned to the Yokosuka Naval District.

25 March 1944:
At 0500, arrives at Moji.

6 April 1944:
Departs Yokosuka. Later that day, arrives at Tateyama.

7 April 1944:
At 0330, SEIYO MARU departs Tateyama in convoy Higashi-Matsu No. 5 (outbound) consisting of transports ASOSAN, NOTO, TOSAN and MIIKE MARUs escorted by destroyer SATSUKI and kaibokan MANJU and KASADO and CD-4.

10 April 1944:
Arrives at Futami, Chichijima.

18 April 1944:
Departs Futami.

24 April 1944:
Arrives at Palau.

30 April 1944:
Departs Palau in convoy also consisting of SHINROKU and SHINSEI MARUs escorted by destroyer YUZUKI and kaibokan MANJU.

2 May 1944:
MANJU attacks an enemy submarine and claims a kill. Later the same day SHINROKU and SHINSEI MARUs arrive at Davao.

4 May 1944:
Arrives at Balikpapan.

12 May 1944:
Departs Balikpapan.

14 May 1944:
Arrives at Tawi Tawi.

17 May 1944:
Departs Tawi Tawi. Later that day, arrives at Tarakan.

19 May 1944:
Departs Tarakan.

20 May 1944:
Arrives at Tawi Tawi.

23 May 1944:
At 0640, SEIYO MARU departs Tawi Tawi in a convoy consisting of tankers KOKUYO, TATEKAWA and NICHIEI MARUs escorted by destroyers HIBIKI, AKISHIMO and HAMAKAZE.

24 May 1944:
Off Mindanao. At 1517, LtCdr Charles H. Andrews' USS GURNARD torpedoes and sinks TATEKAWA MARU at 05-42N, 125-43E.

25 May 1944:
At 0200, arrives at Davao.

13 June 1944: Operation “A-GO” - The Defense of the Marianas:
Tokyo. The CINC, Combined Fleet, Admiral Toyoda Soemu, (former CO of HYUGA), activates A-GO.

Davao. That same day, battleship FUSO transfers most of her fuel oil to the 1st Supply Force's oilers SEIYO, KOKUYO and NICHIEI MARUs and HAYUSUI.

14 June 1944:
Departs Davao towards the Philippine Sea refueling point with the 1st Supply Force and destroyers HATSUSHIMO, SHIRATSUYU and second-class destroyer TSUGA.

15 June 1944:
90 mile SE of Surigao Strait. SEIYO MARU collides with destroyer SHIRATSUYU and shears off her stern. As she sinks, SHIRATSUYU’s depth-charges explode among survivors in the water. 104 crewmen are killed.

16 June 1944:
At about 1000, the 1st Supply Force's oilers HAYUSUI and NICHIEI, KOKUYO and SEIYO MARUs rendezvous at 11-00N, 130-00E with Vice Admiral Ugaki Matome's (former CO of HYUGA) aborted Operation "Kon" Task Force's Bat Div 1's YAMATO, and MUSASHI, Cru Div 5's HAGURO and MYOKO, DesRon 2's light cruiser NOSHIRO and Des Div 4's OKINAMI, SHIMAKAZE, ASAGUMO, MAIKAZE and MICHISHIO and DesRon 10's YAMAGUMO and NOWAKI.

Ugaki's force is refueled promptly, then his force and the 1st Supply Force head north to join Vice Admiral Ozawa Jisaburo's (former CO of HARUNA) First Mobile Fleet's Main Body. At 1650, they rendezvous with Ozawa. The 1st Supply Force begins to refuel the Mobile Fleet.

17 June 1944:
At 2000, the refueling is completed. At this time, the First Mobile Fleet is at 12-15N, 132-45E. The 1st Supply Force stands by to rendezvous with the 2nd Supply Force's oilers GENYO and AZUSA MARUs enroute from Guimaras. All six oilers then depart the area for a designated standby point at 14-40N, 134-20E.

20 June 1944: - The Battle of the Philippine Sea:
The Supply Forces are attacked by LtCdr J. D. Blitch's seven Grumman "Avenger" TBF torpedo-bombers, 12 Curtiss "Helldiver" SB2C dive-bombers and 16 "Hellcat" F-6F strafers from Task Force 58's USS WASP (CV-18). SEIYO MARU is hit by bombs. Three crewmen are killed. HAYASUI is hit by a bomb and set afire. The 2nd Supply Force's oiler GENYO MARU is damaged by bombs and later scuttled by destroyer UZUKI.

Later, destroyer YUKIKAZE removes SEIYO MARU's crew and scuttles her with a torpedo.

10 August 1944:
Removed from the Navy List.

Authors' Note:
Thanks for assistance goes to Allan Alsleben of Oregon, USA and Mr. Gilbert Casse of France.

- Bob Hackett and Peter Cundall.

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