SENSUIKAN!

© 2001-2016 Bob Hackett & Sander Kingsepp
Revision 3

9 February 1942:
Laid down at Yokosuka Navy Yard as submarine No. 163.

16 September 1942:
Launched as I-185.

20 May 1943:
LtCdr (later Rear Admiral, JMSDF) Sekido Yoshimitsu (57) (former CO of I-5) is appointed Chief Equipping Officer (CEO).

23 September 1943:
Completed and attached to Sasebo Naval District. Assigned to SubRon 11 for working-up. LtCdr Sekido Yoshimitsu is the CO.

2 December 1943:
Arrives at Sasebo.

20 December 1943:
Reassigned to SubDiv 22, Sixth Fleet, with I-177, I-180 and I-181.

5 January 1944:
Departs Sasebo for Truk.

12 January 1944:
Early in the morning arrives at Truk, entering the lagoon via North Pass.

22 January 1944:
Reassigned to Southeast Area Fleet.

23 January 1944:
Truk. Submarine depot ship HEIAN MARU transfers stores to I-185.

25 January 1944:
Departs Truk for Rabaul, New Britain, but is forced to return because of a mechanical failure.

27 January 1944:
In the afternoon, departs Truk for Rabaul.

31 January 1944:
The Battle of the Green Islands:
A 360-strong Allied raiding force lands on Nissan, the largest island of the Green Islands group (Papua New Guinea), retiring to Vella Lavella soon thereafter.

Alerted by the local garrison, the C-in-C of the Southeast Area Fleet in Rabaul, Vice Admiral Kusaka Jinichi (37) decides to reinforce Nissan, using a 123-strong naval infantry company hastily formed from the personnel of the 8th Base Force and the 86th Guard Force. This unit, dubbed Wada Detachment after its CO, Lt Wada, is to be transported to Nissan by two submarines. I-185 arrives at Rabaul and immediately commences embarking naval infantry, as well as ammunition and food. [1]

1 February 1944:
The reinforcement of Nissan:
Departs Rabaul for the Green Islands with I-169.

3 February 1944:
About 0500, both submarines arrive at Green. Because of heavy seas, only 77 soldiers can be transferred ashore. Both submarines return with 46 soldiers still aboard.

4 February 1944:
Returns to Rabaul.

12 February 1944:
At noon, departs Rabaul on a supply run to the Iboki Plantation, New Britain.

13 February 1944:
After sundown arrives at Iboki, unloads her cargo, then departs for Rabaul.

15 February 1944: Operation "Squarepeg" – the seizure of Green Islands:
The units of the New Zealand 3rd Infantry Division and the US troops land on Nissan and the nearby islands.

16 February 1944:
Returns to Rabaul.

24 February 1944:
Departs Rabaul for a supply run to Buka Island, Papua New Guinea.

28 February 1944:
I-185 is diverted to intercept an American task force reported in vicinity.

1 March 1944:
Returns to Rabaul.

4 March 1944:
Departs Rabaul for a supply run to Buka Island.

5 March 1944:
E of New Ireland. While recharging batteries, I-185 is attacked by an Allied bomber and receives medium damage as a result of near misses. She develops a serious fuel leak, some 25 per cent of the battery cells are contaminated and the gyro-compass breaks down. LtCdr Sekido decides to abort the mission and to return to Rabaul. [2]

10 March 1944:
A fire breaks out in the battery compartment. LtCdr Sekido contacts his base and receives the order to head for Truk since Rabaul has been recently attacked by Allied bombers.

17 March 1944:
Arrives at Truk. Undergoes emergency repairs.

22 March 1944:
Departs Truk, but is forced to return because of a faulty gyro-compass.

23 March 1944:
Departs Truk for Sasebo.

31 March 1944:
Arrives at Sasebo.

30 April 1944:
Sasebo. Lt (promoted LtCdr 1 May; Cdr, posthumously) Arai Jun (63)(former CO of I-158) is appointed CO. [3]

11 June 1944:
I-185 departs Kure with ComSubDiv 22, Capt (Rear Admiral, posthumously) Kayabara Yasuchika (49) embarked on a supply mission to Wewak, New Guinea. Her decks are piled high with drums of rice, but en route heavy seas wash most of them overboard.

13 June 1944: Operation "A-Go" - The Defense of the Marianas:
Admiral Toyoda Soemu (33)(former CO of HYUGA), CINC, Combined Fleet, orders Vice Admiral (Admiral, posthumously) Takagi Takeo (39)(former CO of MUTSU), CINC, Advance Expeditionary Force (Sixth Fleet) to redeploy his submarines to the Marianas. From his headquarters on Saipan, Takagi orders all available submarines to deploy E of the Marianas.

15 June 1944: American Operation "Forager" - The Invasion of Saipan:
Vice Admiral (later Admiral) Richmond K. Turner's (USNA '08) Task Force 52 lands Marine LtGen Holland M. Smith's V Amphibious Corps and the invasion begins. Communications between Takagi's Sixth Fleet are disrupted by the invasion. Command of the Sixth Fleet's submarines passes to Rear Admiral Owada Noboru (44)(former CO of YAMASHIRO), ComSubRon 7, at Truk. At 2230 (JST), I-185 transmits her last situation report.

16 June 1944:
I-185 receives orders to abort her supply mission to Wewak. Admiral Owada orders I-185 and I-5, I-6, I-41 and I-184 to take up stations in a north-south picket line 300 miles E of the Marianas. I-185 is assigned to patrol next to the northernmost picket.

22 June 1944:
Cdr Lawrence B. Cook's USS NEWCOMB (DD-586) is the flagship of a screen guarding troop transports heading to Saipan. At 0903, NEWCOMB, operating with LtCdr H. L. Thompson's fast minesweeper CHANDLER (DMS-9), makes a sonar contact with a submarine and commences an attack with depth charges. The contact is then lost until 1023, when CHANDLER's depth-charge attack brings up some oil. NEWCOMB conducts another attack, but without any visible results. After the last attack made by CHANDLER at 1144, a deep-sea explosion is heard; cork slabs, wood, diesel oil and human entrails emerge at 15-50N, 145-08E.

That same day, Rear Admiral Owada orders I-185 and all but six of the Sixth Fleet's submarines to withdraw from the Marianas. The order comes too late for I-185.

12 July 1944:
Presumed lost with all 95 hands in the Saipan area.

10 September 1944:
Removed from the Navy List.

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Authors' Note:
[1] The Allied radio intelligence designated Wada Detachment as Green Island Mopping Up Force. Its existence was first discovered on 3 February, but initially FRUMEL wrongly assumed that it already had sailed from Truk on 27 January.

[2] On that day, a Lockheed PV-1 "Ventura" from RNZAF No. 2 BR Sqn reported an attack on a submarine in that area, which resulted in possible damage. In all likelihood, the target was I-185.

[3] Boyd and Yoshida (1995) identify the officer in question as Arai Atsushi. The Japanese Navy List of 1937, however, identifies him as Arai Jun.

Thanks go to Dr. Higuchi Tatsuhiro of Japan.

Special thanks also go to Hans Mcilveen of the Netherlands for research based on wartime FRUMEL intercepts.

– Bob Hackett and Sander Kingsepp.

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