SENSUIKAN!

© 2001-2017 Bob Hackett & Sander Kingsepp
Revision 3

19 June 1941:
Laid down at Sasebo Navy Yard as Submarine No. 151.

15 April 1942:
Launched as I-38. Provisionally attached to Kure Naval District.

1 November 1942:
LtCdr (Captain, posthumously) Watanabe Katsuji (55) (current CO of I-169) is appointed the Chief Equipping Officer (CEO) of I-38 as an additional duty.

5 December 1942:
Cdr (Rear Admiral, posthumously) Ankyu Eitaro (50)(former CO of I-1) is appointed the CEO.

31 January 1943:
Sasebo Navy Yard. I-38 is completed and registered in the IJN. Attached to Kure Naval District. Assigned to Kure Submarine Flotilla. Cdr Ankyu Eitaro is the CO.

Departs for Kure to participate in the tests of the new type shallow depth torpedoes in Inland Sea. Later participates in the tests of an "Unpoto" gun sled. I-38 is the first IJN submarine to be fitted with this new weapons carrier. [1]

1 April 1943:
Reassigned to SubRon 11 for working-up.

30 April 1943:
Reassigned to SubDiv 15, SubRon 1.

8 May 1943:
Departs Kure for Osako with an "Unpoto" gun sled mounted on her afterdeck. Later that day departs Osako for an overnight stop at Saeki.

9 May 1943:
Departs Saeki for Truk, towing the "Unpoto" sled.

14 May 1943:
Arrives at Truk.

15 May 1943:
Assigned to Southeast Submarine Force. Vice Admiral, the Marquis, Komatsu Teruhisa (former CO of NACHI), CINC, Sixth Fleet, inspects I-38 and her "Unpoto" installation. Later that day, she unloads her provisions. A repair ship comes alongside to repair the sledge.

16 May 1943:
Departs Truk for Rabaul.

18 May 1943:
Arrives at Rabaul. The "Unpoto" is detached and some provisions are transferred to the submarine depot ship CHOGEI. Cdr Ankyu is briefed aboard CHOGEI by Rear Admiral Harada Kaku (41), ComSubRon 7.

19 May 1943:
I-38 conducts an "Unpoto" launch test in the presence of Vice Admiral Kusaka Jinichi (37), CINC of the Southeast Area Fleet, and Gen Imamura Hitoshi, CINC, Eighth Area Army.

The remaining provisions from the aft storerooms are transferred to CHOGEI. I-38 also transfers all her torpedoes except four to CHOGEI.

21 May 1943:
I-38 departs Rabaul on her first supply run to Lae, New Guinea, carrying 48.6 tons of ammunition and provisions in addition to 12 officers of the 7th Base Unit.

23 May 1943:
I-38 arrives at Lae and makes a rendezvous with two Daihatsu barges offshore. After embarking 17 sick and wounded IJA soldiers, I-38 departs. She is then spotted by a PT boat that fires a total of six torpedoes at her, but they all miss.

25 May 1943:
Returns to Rabaul.

27 May 1943:
Departs Rabaul on her second supply run to Lae with 48.6 tons of food, medicines and 29 marines of the Sasebo 5th Special Naval Landing Force (SNLF).

28 May 1943:
Off Lae, I-38's lookouts spot a PT boat and the submarine dives away. All cargo is transferred and six IJA soldiers are taken aboard at Lae that night.

31 May 1943:
Returns to Rabaul and receives a new cargo from GOSHU MARU.

2 June 1943:
Departs Rabaul on her third supply run to Lae.

4 June 1943:
Off Lae. I-38 makes a rendezvous with a Daihatsu barge. Cdr Ankyu embarks Gen Imamura Hitoshi, CINC, Eighth Area Army, and three of his staff officers, returning to Imamura's HQ in Rabaul.

6 June 1943:
Returns to Rabaul. I-38 embarks new cargo from TAISEI MARU. An "Unpoto" sledge is again mounted on her afterdeck.

9 June 1943:
Departs Rabaul on her fourth supply run to Salamaua and Lae.

11 June 1943:
Arrives at Salamaua, unloads her cargo, then proceeds to Lae.

12 June 1943:
Arrives at Lae. The rest of the cargo and the gun sledge are disembarked in exchange for six IJA soldiers. This is the first successful delivery of artillery pieces, using an "Unpoto" sledge.

Soon after departure, an enemy plane spots I-38 and Cdr Ankyu crash-dives. The plane drops three bombs, but they all miss. About midnight, I-38 is spotted by another plane and again crash-dives.

13 June 1943:
Returns to Rabaul.

15 June 1943:
Refuels from oiler NARUTO.

17 June 1943:
I-38 receives a new "Unpoto" sledge from TAISEI MARU.

19 June 1943:
Departs Rabaul for her fifth supply run to Lae, carrying 48.5 tons of provisions.

21 June 1943:
Arrives at Lae and disembarks the provisions.

23 June 1943:
Returns to Rabaul.

24 June 1943:
I-38 receives another new "Unpoto" sledge from TAISEI MARU.

25 June 1943:
I-38 undergoes maintenance work and her upper deck is repainted.

26 June 1943:
Departs Rabaul for her sixth supply run to Lae, carrying 48.5 tons of provisions.

28 June 1943:
At sunset, arrives at Lae. The cargo is disembarked in exchange for 15 IJA soldiers.

30 June 1943:
Returns to Rabaul. It is decided to divert her temporarily to commerce raiding operations.

1 July 1943:
Takes aboard supplies from submarine tender CHOGEI.

2 July 1943:
Departs Rabaul on her first war patrol to raid enemy communications and reconnoiter Kula Gulf.

4 July 1943:
Arrives at her prescribed area.

5 July 1943:
Cdr Ankyu spots two enemy transport vessels but is unable to attack.

6 July 1943:
In the morning, Cdr Ankyu fires a torpedo on an American destroyer but misses.

7 July 1943:
New Georgia Sound. At night, the surfaced I-38 is suddenly attacked by an enemy warship (probably USS WALLER (DD-466) at 08-00S, 158-05E). The destroyer engages I-38 with guns and machine-gun fire. Cdr Ankyu crash-dives. Ten minutes later the enemy vessel drops a pattern of depth charges. I-38 dives to 265 ft (80 meters). The enemy vessel continues the chase for one-and-one-half hours.

8 July 1943:
Reconnoiters the Kula Gulf.

9 July 1943:
At night, again reconnoiters the Kula Gulf.

10 July 1943:
Reconnoiters the Kula Gulf for the third time, then receives an order to return to Rabaul to continue the supply missions.

11 July 1943:
En route to Rabaul, I-38 is repeatedly subjected to air attacks, crash-diving each time.

12 July 1943:
Arrives at Rabaul.

17 July 1943:
Departs Rabaul on her seventh supply run to Lae.

19 July 1943:
At night, arrives at Lae, disembarking her cargo. On her way back, she is attacked repeatedly by enemy bombers.

21 July 1943:
Returns to Rabaul.

23 July 1943:
I-38 receives a new "Unpoto" sledge and cargo.

24 July 1943:
Departs Rabaul on her eighth supply run to Lae.

26 July 1943:
At night, arrives at Lae, disembarks her cargo.

28 July 1943:
Returns to Rabaul.

30 July 1943:
Departs Rabaul on her ninth supply run to Lae. Five or six supply drums are lost en route.

2 August 1943:
Arrives at Lae.

3 August 1943:
Returns to Rabaul.

6 August 1943:
Departs Rabaul on her tenth supply run to Lae.

8 August 1943:
Arrives at Lae and disembarks her cargo.

9 August 1943:
En route back to Rabaul, I-38's lookouts spot an airplane and she crash-dives.

10 August 1943:
Returns to Rabaul.

12 August 1943:
I-38 receives new cargo from NAGOYA MARU.

14 August 1943:
Departs Rabaul on her 11th supply run, this time to Kolombangara. About 100 miles from Rabaul, I-38 is strafed and bombed by an enemy plane.

15 August 1943:
At night, I-38 is attacked by six enemy aircraft and depth-charged.

17 August 1943:
Arrives at Kolombangara and disembarks her cargo.

19 August 1943:
En route to Rabaul, I-38's lookouts spot six B-24s. The submarine crash-dives.

20 August 1943:
Returns to Rabaul.

26 August 1943:
Receives a new Unpoto from TOYO MARU.

28 August 1943:
Departs Rabaul on her 12th supply run to Lae.

30 August 1943:
Arrives at Lae, disembarks her cargo.

1 September 1943:
En route to Rabaul, I-38 is spotted by enemy aircraft and dives several times. Returns to Rabaul.

2 September 1943:
Receives a new Unpoto from TOYO MARU.

7 September 1943:
Departs Rabaul on her 13th supply run to Kolombangara.

10 September 1943:
While negotiating the entrance to the Kolombangara Gulf, I-38 is attacked by an enemy aircraft that drops a bomb, but misses. I-38 continues her voyage to Shortland without disembarking her cargo.

12 September 1943:
I-38 arrives at Shortland and disembarks her cargo. Thirty minutes after her departure her lookouts spot an aircraft and I-38 crash-dives.

At 2300, I-38, continuing her voyage on the surface, is suddenly attacked by an aircraft that drops three bombs, but they all miss. The plane had apparently switched off its engine before diving to remain unnoticed.

13 September 1943:
Returns to Rabaul.

17 September 1943:
Receives a new cargo of provisions from TOYO MARU.

20 September 1943:
Departs Rabaul for her 14th supply run to Finschafen with ComSubDiv 15 Captain Nagai Takeo (47) embarked.

22 September 1943:
I-38 arrives in her prescribed area but fails to establish a contact with the IJA garrison. She retreats to outer sea.

23 September 1943:
I-38 approaches Finschafen again, but there is still no answer from the ground troops. Later that night, she spots an enemy convoy but is unable to attack because of her cargo.

24 September 1943:
Cdr Ankyu makes a final attempt to contact the garrison of Finschafen. I-38 is then ordered to patrol in the area until 27 September and then move to Sarmi (aka Sulumi) on the north coast of New Guinea.

27 September 1943:
Arrives at Sarmi and delivers half of her cargo.

28 September 1943:
Returns to Rabaul.

3 October 1943:
I-38 departs on her 15th supply mission to Sarmi.

5 October 1943:
Arrives at Sarmi and starts to disembark her cargo. With two thirds of the cargo still on the upper deck, she is attacked by an enemy aircraft and dives immediately. She later surfaces to unload the rest of her cargo, then departs for Rabaul.

8 October 1943:
Returns to Rabaul.

10-13 October 1943:
I-38 participates in "Unkato" container towing tests at Rabaul. The tests end in failure.

12 October 1943: Air raid on Rabaul:
At Rabaul. LtGen (later General) George C. Kenney's 5th Air Force hits Rabaul with the biggest raid made up to then in the Pacific war. Three hundred forty-nine aircraft, including 87 B-17 and B-24 bombers, 114 B-25 strafers, 12 RAAF "Beaufighters", 125 P-38 "Lightning" fighters and others from New Guinea and Australia hit Rabaul's airfields and the Simpson Harbor.

I-38, I-36, I-176, I-177, RO-105 and RO-108 are moored in deep water. The harbor is bombed, but when the attack begins, most of the submarines submerge to safety.

15 October 1943:
Departs Rabaul on her 16th supply run to Sarmi.

16 October 1943:
Arrives at Sarmi. The transfer of the cargo is suspended because of a severe thunderstorm. An enemy PT boat attacks I-38 and forces her to dive. The boat then drops four depth-charges.

17 October 1943:
After sundown I-38 approaches Sarmi again. Two Daihatsu barges from the base succeed in unloading 80 per cent of her cargo. Departs Sarmi for Rabaul.

18 October 1943:
Off Rabaul, I-38's lookouts spot enemy aircraft bound for Rabaul. She is forced to dive four times. Returns to Rabaul.

20-21 October 1943:
Rabaul. I-38 participates in another "Unkato" towing test.

24 October 1943:
Departs Rabaul on her 17th supply run to Sarmi. Around 0915, her lookouts spot enemy aircraft bound for Rabaul; the submarine submerges.

25 October 1943:
Arrives at Sarmi, delivers her cargo and departs for Rabaul. En route, an enemy aircraft forces her to dive.

26 October 1943:
I-38 returns to Rabaul.

29 October 1943:
Departs Rabaul on her 18th supply run to Sio. En route, an incoming enemy aircraft formation forces her to submerge.

31 October 1943:
Arrives at Sio and transfers her cargo, then departs for Rabaul.

1 November 1943: American Operation "Shoestring II": The Invasion of Bougainville:
Rear Admiral (later Vice Admiral) Theodore S. Wilkinson's Third Amphibious Force, TF 31, lands Lt Gen (later General/Commandant) Alexander A. Vandegrift's 1st Marine Amphibious Corps at Cape Torokina, Empress Augusta Bay, Bougainville, Solomons.

2 November 1943:
I-38 returns to Rabaul around 1300 (local). The harbor and Rabaul's airfields are attacked by 75 North American B-25 "Mitchells" escorted by 70 P-38 Lockheed "Lightning" fighters in support of the landings on Bougainville. I-38 submerges. After the raid, I-38 scuttles one of the crippled vessels with her deck gun.

The B-25's and P-38's claim 12 aircraft destroyed on the ground and 68 shot down during the raid. AA and air opposition is the strongest thus far encountered by the Fifth Air Force. 21 American planes are lost.

4 November 1943:
I-38 embarks cargo for the next supply run to Sio.

5 November 1943:
Departs Rabaul on her 19th supply run to Sio, towing an "Unkato" container. En route she is attacked by enemy aircraft and crash-dives. After surfacing, I-38 abandons the container.

7 November 1943:
In the evening, arrives at Sio, disembarks her cargo, taking aboard wounded and sick soldiers in exchange, then departs for Rabaul.

9 November 1943:
En route Allied reconnaissance aircraft are spotted and the submarine dives twice. Returns to Rabaul.

16-17 November 1943:
I-38 participates in more "Unkato" towing experiments off Rabaul.

18 November 1943:
Departs Rabaul on her 20th supply run to Sarmi.

19 November 1943:
While running surfaced, I-38 is attacked by an enemy PT boat but manages to crash-dive and escape. The boat drops four depth-charges. Arrives at Sarmi, unloads her cargo, then departs for Rabaul.

20 November 1943:
Returns to Rabaul.

23 November 1943:
Departs Rabaul on her 21st supply run to Sio.

25 November 1943:
Arrives at Sio and unloads her cargo, then departs for Rabaul.

26 November 1943:
On her way to Rabaul, I-38 is attacked by an enemy bomber that drops a bomb but misses.

27 November 1943:
Returns to Rabaul.

1-7 December 1943:
I-38 participates in more "Unkato" towing experiments and a speed trial.

3 December 1943:
On that day, the Fleet Radio Unit, Melbourne (FRUMEL) provides the following information, originating from an unidentified source:

"The transport run to Sulumi by submarine I-38 is postponed."

6 December 1943:
On that day, the FRUMEL provides the following digest, originating from a Southeast Submarine Force radio message:

"Transport to Sulumi Air Base by submarine I-38 is postponed 1 day."

7 December 1943:
Departs Rabaul on her 22nd supply run to Sarmi, towing an "Unpoto" sledge.

9 December 1943:
Arrives at Sarmi. Disembarks her cargo and hands over the "Unpoto" to a Daihatsu barge from the local base.

11 December 1943:
Returns to Rabaul.

18-19 December 1943:
Participates in more "Unkato" towing experiments.

19 December 1943:
Departs Rabaul for her 23rd supply run to Sio, towing an "Unkato".

20 December 1943:
Detached from Southeast Submarine Force.

21 December 1943:
Arrives at Sio, disembarking her cargo, then returns to Rabaul.

24 December 1943:
Returns to Rabaul. In her 23 supply runs from Rabaul to Lae, Sio, Kolombangara and Sarmi, I-38 carries a total of 753 tons of cargo. In March 1944 Cdr Ankyu receives a citation from Admiral Koga Mineichi (former CO of ISE), CinC, Combined Fleet, for I-38's feats.

26 December 1943:
Departs Rabaul for Truk.

29 December 1943:
Arrives at Truk via South Pass.

30 December 1943:
At 1500, departs Truk for Kure.

1 January 1944:
I-38 is in SubRon 1's SubDiv 15 with I-32, I-35, I-36 and I-41.

7 January 1944:
Arrives at Kure for repairs and overhaul.

15 January 1944:
After SubRon 1 is deactivated, the SubDiv 15 is directly attached to Sixth Fleet.

15 February-5 March 1944:
Cdr Ankyu is detailed to the Otake submarine school as an instructor with joint duty at its research department. No new CO is appointed during that period.

6 March 1944:
Cdr Ankyu Eitaro is again appointed the CO of I-38.

14 March 1944:
Departs Kure for Truk under command of LtCdr (Cdr, posthumously) Toyama Zenshin (59)(former CO of I-169), officially in charge from 15 March.

19 March 1944:
Truk. Subchaser CH-20 and FUYO MARU escort I-2 and I-38 into the lagoon.

30 March 1944:
Departs Truk on her second war patrol to Palau area.

4 April 1944:
LtCdr Toyama receives the order to proceed to Wewak, New Guinea and embark the staff of the Ninth Fleet for a transfer to Hollandia.

8 April 1944:
Arrives at Wewak, embarks the first section of the staff of the Ninth Fleet, departs for Hollandia, New Guinea that same day.

10 April 1944:
Arrives at Hollandia where the staff of the Ninth Fleet leaves the boat. Departs for Wewak to transport the rest of the fleet staff officers.

12 April 1944:
Arrives at Wewak, embarks the second section of the staff of the Ninth Fleet, departs for Hollandia again.

14 April 1944:
Arrives at Hollandia, unloads the second section of the fleet staff, then departs for Truk.

18 April 1944:
LtCdr (promoted Cdr 1 November 1944; Capt, posthumously) Shimose Kichiro (58)(former CO of I-6) is appointed the CO.

19 April 1944:
Arrives at Truk.

20 April 1944:
Departs Truk for Kure.

27 April 1944:
Returns to Kure.

April 1944:Operation "Tatsumaki" (Tornado) - Amphibious Tank Attack at Majuro, Marshall Islands:
Inland Sea. I-38 participates in training with I-36, I-41, I-44 and I-53. The operation calls for the submarines to carry amphibious tanks armed with torpedoes from Kure to Majuro. There they are to be put ashore, make their way overland, enter the water again and make a torpedo attack on American ships. Later, the plan is cancelled.

18 May 1944:
Departs Kure to patrol E of the Marshalls and reconnoiter Kwajalein with an E14Y1 "Glen" floatplane (her third war patrol). En route, LtCdr Shimose receives an order to reconnoiter Majuro instead.

13 June 1944: Operation "A-Go"- The Defense of the Marianas:
Admiral Toyoda Soemu (former CO of HYUGA), CINC, Combined Fleet, orders Vice Admiral Takagi Takeo (former CO of MUTSU), CINC, Sixth Fleet (Submarines), to redeploy his boats to the Marianas. From his headquarters on Saipan, Takagi orders all available submarines, including I-38, to deploy to the east of the Marianas.

15 June 1944: American Operation "Forager"- The Invasion of Saipan:
Vice Admiral Richmond K. Turner's Task Force 52 lands Marine Lt Gen Holland M. Smith's V Amphibious Corps and the invasion begins. Communications between Takagi's Advance Expeditionary Force (Sixth Fleet) are disrupted by the invasion.

Command of the Sixth Fleet's submarines passes to ComSubRon 7, Rear Admiral Owada Noboru (former CO of YAMASHIRO), at Truk. Owada orders all of the Sixth Fleet's submarines to withdraw from the Marianas area except I-38, I-6, I-10, I-41, I-53 and RO-47.

16 June 1944:
I-38 is assigned to "A" Submarine Unit, operating east of the Marianas.

28 June 1944:
LtCdr Shimose receives an order to evacuate the staff of the Sixth Fleet from Saipan, but he does not succeed.

2 July 1944:
Vice Admiral Takagi cancels all further rescue efforts of his staff.

7 July 1944:
LtCdr Shimose receives the order to return to Japan.

16 July 1944:
Arrives at Sasebo for a refit. Anti-radar coating is applied.

15 September 1944: American Operation "Stalemate II" - The Invasion of the Palaus:
Admiral (later Fleet Admiral) William F. Halsey's Third Fleet lands the First Marine Division on Peleliu and the Army's 81st Division on Anguar Island.

13 October 1944: Operation "Sho-I-Go" - The Defense of the Philippines:
Admiral Toyoda orders the Sho-1-Go plan activated.

18 October 1944:
I-38 is assigned to "B" Submarine Unit.

19 October 1944:
I-38 departs Kure on her fourth war patrol to patrol E of the Philippines in company of I-41.

20 October 1944: American Operation "King Two" - The Invasion of Leyte, Philippines:
Admiral Halsey's Third Fleet of 738 ships including 18 aircraft carriers, six battleships, 17 cruisers, 64 destroyers and over 600 support ships land the Army's X Corps (24 th Infantry and 1st Cavalry Divisions) and the XXIV Corps (7th, 77th and 96th Infantry Divisions) that begins an 8-month campaign to retake Leyte.

25 October 1944:
I-38 arrives at her prescribed area E of Leyte and Samar.

5 November 1944:
LtCdr Shimose is ordered to reconnoiter the Ngulu Islands on 11 November to determine whether American fleet is using it. The IJN staff needs the information to plan future "kaiten" human torpedo missions.

7 November 1944:
E of Luzon. I-38 reports sighting an enemy task force. It is her last signal.

12 November 1944:
Cdr (later Vice Admiral/Commandant USNA) Robert T.S. Keith's USS NICHOLAS (DD-449) and Cdr N. J. F. Frank's TAYLOR (DD-468) are escorting ST LOUIS (CL-49) from Ulithi to Kossol Roads, Palau.

E of Palau. At 2003, NICHOLAS' SG radar picks up a surface contact at 22,000 yds. Keith closes and opens fire with his 5-in main armament, but the contact disappears. About 2230, NICHOLAS reacquires the target by sonar and drops a pattern of 18 depth charges. The contact is lost.

13 November 1944:
At about 0030, NICHOLAS is hunting for the target when she makes another sonar contact. As Cdr Keith prepares to attack, his sonar officer warns that the contact is turning hard right. Keith also goes hard right, backs on his starboard engine and, practically on top of the contact, drops a salvo of depth charges. A few minutes after the last charge goes off, NICHOLAS is rocked by a huge underwater explosion that sinks the submarine - most likely I-38 - at 08-04N, 138-03E. [2]

That day, I-38 fails to send a signal to the Sixth Fleet HQ. In the morning, debris and human remains are sighted in the attack area.

6 December 1944:
Presumed lost off the Palaus with all 110 hands.

10 March 1945:
Removed from the Navy List.

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Authors' Notes:
[1] The "Unpoto" was a 70-ft sled that could carry up to 15 tons of cargo, usually three 15 cm Type 96 howitzers with some ammunition. The "Unkato" was a 135-ft submersible cargo container capable of carrying 377 tons of supplies on one-way trips in which they were released, recovered and unloaded by the receipients of the supplies.

[2] Some older sources identify I-38 as the submarine destroyed by the US minesweeper ARDENT (AM-340) and the USCG cutter ROCKFORD (PF-48) on 13 November 1944. In all likelihood their target was I-12.

Special thanks go to Dr. Higuchi Tatsuhiro of Japan and Hans Mcilveen of the Netherlands for info on FRUMEL intercepts.

– Bob Hackett and Sander Kingsepp

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