(Type A1 Submarine)

IJN Submarine I-10:
Tabular Record of Movement

© 2001-2016
Revision 6

7 June 1938:
Kobe. Laid down at Kawasaki's Yard.

29 September 1939:
Launched. [1]

31 July 1941:
Cdr (later Captain) Kayabara Yasuchika (49)(former CO of I-121) is appointed Chief Equipping Officer.

31 October 1941:
Completed and registered in the Sasebo Naval District. Cdr Kayabara is appointed the Commanding Officer.

10 November 1941: Operation "Z":
I-10 is the flagship of SubRon 2. Vice Admiral Shimizu Mitsumi (former CO of ISE), CINC, Sixth Fleet (Submarines) convenes a meeting of his commanders aboard flagship light cruiser KATORI. Captain (later Rear Admiral) Mito Hisashi, Chief of Staff, Sixth Fleet briefs the assembled commanders on the planned attack on Pearl Harbor.

I-10 and I-26 are assigned to the Sixth Fleet's Reconnaissance Unit under Cdr Kayabara. I-10 is assigned to reconnoiter areas in the Fiji, Samoa and Tutuila in the South Pacific and I-26 is assigned to the Aleutians area.

16 November 1941:
I-10 departs Yokosuka for the South Pacific on her first war patrol.

23 November 1941:
Arrives at Kwajalein to refuel, then proceeds to Fiji area.

30 November 1941:
Off Fiji. I-10 launches a Watanabe E9W1 "Slim" floatplane piloted by Lt Ando Yasuo to reconnoiter Suva Bay. Lt Ando reports that there are no warships at Suva, but fails to return. After a three-day fruitless search under radio silence I-10 departs the area, reporting the loss of its plane to the Sixth Fleet HQ. [2]

2 December 1941:
The coded signal "Niitakayama nobore (Climb Mt. Niitaka) 1208" is received from the Combined Fleet. It signifies that hostilities will commence on 8 December (Japan time). [3]

4 December 1941:
Pago Pago. I-10 conducts a submerged reconnaissance. Cdr Kayabara sights a ship that he identifies as an American ASTORIA-class cruiser.

7 December 1941:
I-10 is stationed 1,300 miles S of Oahu.

9 December 1941:
Departs her patrol area to join the hunt for USS LEXINGTON (CV-2), detected by I-18.

700 miles SE of Hawaii. After nightfall, I-10 torpedoes 4,132-ton Danish motor vessel NORDHVAL, now flying the Panamanian flag as DONERAIL, sailing from Suva to Vancouver with a cargo of sugar and pineapples.

I-10 surfaces and fires twenty shells at the sinking ship, one of which demolishes the starboard lifeboat still suspended from the davits, killing its crew. Two hours later, DONERAIL sinks at 08N, 152W. Of 43 sailors and passengers, only 8 reach Tarawa, Gilberts 38 days later.

12 December 1941:
I-10 is reassigned to Advance Unit. On that same day, she is ordered to proceed to the West Coast of the United States to attack shipping. I-10 is assigned to patrol off San Diego, California.

9 January 1942:
I-10 is directly attached to the Sixth Fleet HQ.

11 January 1942:
Arrives at Kwajalein.

12 January 1942:
Departs Kwajalein for Yokosuka.

21 January 1942:
Returns to Yokosuka.

10 March 1942:
Reassigned to SubRon 8.

12 March 1942:
Departs Yokosuka to chase the carriers of Vice Admiral Wilson Brown, Jr.’s Task Force 11.

16 March 1942:
Vice Admiral, the Marquis, Komatsu Teruhisa (former CO of NACHI) assumes command of the Sixth Fleet (Submarines).

20 March 1942:
Returns to Kure.

27 March 1942:
The German naval staff requests the IJN to launch operations against Allied convoys in the Indian Ocean.

8 April 1942:
The Japanese formally agree to dispatch submarines to the East Coast of Africa. The 1st Division of SubRon 8 is withdrawn from its base at Kwajalein in the Marshall Islands.

16 April 1942:
I-10 is the flagship of Captain (later Rear Admiral) Ishizaki Noboru's (former CO of HYUGA) SubRon 8, in the "KO" detachment with I-16, I-18, I-20, I-30 and their support ships, the auxiliary cruisers/supply ships AIKOKU and HOKOKU MARUs.

Hashirajima, Hiroshima Bay. Vice Admiral Komatsu, Captain Ishizaki their staffs and midget submarine crews pay a courtesy call on the CINC, Combined Fleet, Admiral Yamamoto aboard his flagship, new battleship YAMATO. At 1100, the KO detachment departs for Penang, Occupied British Malaya.

23 April 1942:
Arrives at Singapore.

24 April 1942:
Departs Singapore for Penang.

25 April 1942:
Arrives at Penang.

30 April 1942:
Penang. The KO detachment (less I-10 and I-30) load midget submarines aboard. I-10 is to reconnoiter selected points on the East African coast for possible attack. I-30 is assigned a similar reconnaissance mission and departs in advance. I-10, with Captain Ishizaki embarked, and the KO detachment depart Penang on her second war patrol and sortie westward in the Indian Ocean.

20 May 1942:
The E14Y1 "Glen" from I-10 piloted by Lt (jg) Araki Toshio conducts a reconnaissance flight over Durban, but no targets of importance are sighted. Araki’s plane is detected from the ground and challenged, but the radioman, FPO2C Ito Yoshiharu, provides a spurious identification signal and escapes.

29 May 1942:
At night, I-10's floatplane reconnoiters the harbor at Diego Suarez (now Antsiranana), Madagascar. The plane sights old ROYAL SOVEREIGN-class battleship (HMS RAMILLIES) at anchor in the bay. Also in the harbor are destroyers HMS DUNCAN and ACTIVE, corvettes HMS GENISTA and THYME, troopship HMS KARANJA, hospital ship ATLANTIS, tanker BRITISH LOYALTY, merchant LLANDAFF CASTLE and an ammunition ship.

Captain Ishizaki orders a midget submarine attack be made the next night.

30 May 1942:
I-16 and I-20 launch their midget submarines about 10 miles from Diego Suarez to penetrate the harbor. At 2025, a midget, probably I-20's, torpedoes RAMILLIES. The torpedo blasts a 30-foot by 30-foot hole in her port bulge. British corvettes GENISTA and THYME drop depth charges. At 2120, I-20's midget under LT Akieda Saburo with PO2C Takemoto Masami fires her second torpedo at RAMILLIES, but 6,993-ton tanker BRITISH LOYALTY, just getting underway, moves directly into the torpedo's path. The tanker is hit in the engine room aft and badly damaged and sinks in about 65 feet of water. (She is later refloated and sunk off Addu Atoll).

After emergency repairs, RAMILLIES is towed to Durban, Union of South Africa for temporary repairs from June to August. RAMILLIES is erroneously considered sunk by the IJN. [4]

31 May 1942:
Lt(jg) Araki conducts his second flight over Diego Suarez in an attempt to locate midget sub crewmembers, who might have escaped ashore.

5 June 1942: Commerce Raiding in the Mozambique Channel, Indian Ocean:
Mozambique Channel, 350 miles E of Beira. At 0231 the I-10 sinks the 2,639-ton Panamanian-flagged steamer ATLANTIC GULF at 21-03S, 37-36E.

At 1044, I-10 sinks 4,999-ton American armed freighter MELVIN H. BAKER (ex-SEEKONK, ex-WILLMOTO) at 21-44S, 36-38W. Her crew is rescued by the British steamer TWICKENHAM.

8 June 1942:
Mozambique Channel, 350 miles E of Beira. At 0953, I-10 torpedoes 5,224-ton British steamer KING LUD, enroute from New York to Bombay, carrying military personnel and government stores. KING LUD sinks at 20S, 40E; there are no survivors.

17 June 1942:
Armed merchant cruisers AIKOKU and HOKOKU MARUs replenish and refuel I-10.

28 June 1942:
Mozambique Channel, S of Beira. I-10 torpedoes 4,957-ton British motor vessel QUEEN VICTORIA sailing from the Tyne to Aden with a cargo of military stores. QUEEN VICTORIA sinks at 21-15S, 40-30E; there are no survivors.

30 June 1942:
Mozambique Channel, S of Beira. At 0030, I-10 torpedoes 6,737-ton American armed steamer EXPRESS enroute from Bombay to Cape Town, carrying manganese ore, jute and leather. EXPRESS is hit to starboard by two torpedoes and sinks by the stern at 23-30S, S, 37-30E. Eleven sailors and two Armed Guardsmen drown, when their boat is swamped in heavy seas. [5]

6 July 1942:
At 1615, I-10 torpedoes and sinks 4,504-ton Greek merchant NYMPHE at 15-48S, 40-42E.

8 July 1942:
Mozambique Channel. At 0748, I-10 torpedoes 5,498-ton British armed steamer HARTISMERE enroute from Philadelphia to Alexandria via Lourenço Marques, carrying 8,000 tons of general cargo. After one hit to the No. 1 hold area, a violent explosion occurs aboard and the crew abandons ship. I-10 surfaces and sinks the burning steamer with gunfire at 18S, 41-22E. The crew and gunners make landfall at Caldera Point, Portuguese East Africa.

At 1755, I-10 torpedoes 4,427-ton Dutch armed merchant ALCHIBA enroute from Durban to London via Aden, carrying 4,000 tons of ammunition. The hit to port side engine room kills five firemen and demolishes two lifeboats; all lights go out and the crew abandons the ship. Following their departure, I-10 surfaces and sinks the stationary steamer with nine shells. ALCHIBA breaks in two and sinks at 18-30S, 41-40E. [6]

30 July 1942:
Returns to Penang.

1 August 1942:
Departs Penang for Yokosuka.

7 August 1942: American Operation "Watchtower" - The Invasion of Guadalcanal, British Solomon Islands:
Rear Admiral (later Admiral) Richmond K. Turner's Amphibious Task Force 62, covered by Vice Admiral (later Admiral) Frank J. Fletcher's Task Force 61 and Rear Admiral (later Admiral) John S. McCain's Task Force 63's land-based aircraft, lands Maj Gen (later Gen/Commandant) Alexander A. Vandegrift's 1st Marine Division on Guadalcanal opening a seven-month campaign to take the island.

12 August 1942:
Arrives at Yokosuka.

15 September 1942:
Cdr Kayabara is relieved by Cdr (later Captain) Yamada Takashi (49) (former CO of I-20).

21 October 1942:
Departs Yokosuka for Truk.

27 October 1942:
Arrives at Truk.

31 October 1942:
Reassigned to the "C" patrol unit.

24 November 1942:
Departs Truk to provide support for the midget submarine attack on Lunga anchorage.

18 December 1942:
Returns to Truk.

5 January 1943:
Departs Truk on her third war patrol to raid enemy communications south of the Solomons and reconnoiter Noumea, New Zealand and the Torres Strait.

10 January 1943:
I-10 passes the area E of Solomons, heading for the New Caledonia.

16 January 1943:
80 miles SSE of Noumea. I-10 chases a carrier escorted by two destroyers, but her approach fails and all torpedoes miss.

20 January 1943:
S of Noumea. At 0015 LtCdr Yamada sights an unescorted transport.

23 January 1943:
At 0020 two destroyers are sighted E of Noumea.

24 January 1943:
After nightfall, the E14Y1 "Glen" from I-10, piloted by Lt (jg) Sasakura Atsumi, conducts a flight over Noumea. At 0100, Sasakura reports the sighting of several battleships, cruisers, destroyers and transports. [7]

30 January 1943:
Coral Sea, 115 miles S from Amédée lighthouse, New Caledonia. At 0449, I-10 torpedoes 7,176-ton American "Liberty" ship SAMUEL GOMPERS en route from Noumea to Newcastle. GOMPERS receives one hit to the stern, explodes and sinks in 5 minutes at 24-28S, 166-20E.

9 February 1943:
Around 1400 the I-10 attacks an unescorted transport, but her torpedo passes below the keel of the target.

10 February 1943:
At 0542 the I-10 attacks another transport in the same area, but her approach fails and all torpedoes miss.

14 February 1943:
Arrives off Auckland.

16 February 1943:
Arrives off Wellington.

22 February 1943:
After intercepting several radio messages from I-10, Allied radio intelligence concludes that she is about to navigate the Cook Strait that night. RNZAF air search fails to find any traces of the Japanese submarine in that area (in fact, I-10 had passed it more than a week ago).

27 February 1943:
At 1050, I-10 attacks another transport, but misses.

1 March 1943:
New Hebrides. I-10 torpedoes 7,141-ton American tanker GULFWAVE at 20-30S, 174-45E, but GULFWAVE reaches Suva, Fiji, under her own power and suffers no casualties.

5 March 1943:
I-10 reconnoiters Torres Strait.

12 March 1943:
Returns to Truk.

15 March 1943:
Departs Truk for Sasebo.

21 March 1943:
Arrives at Sasebo for repairs.

15 April 1943:
Cdr Yamada is relieved by Cdr Tonozuka Kinzo (50)(former CO of I-34).

17 May 1943:
Departs Sasebo to work up in the western part of the Inland Sea.

19-21 May 1943:
Iyo Sea. I-10 and I-8 conduct refueling exercises.

26 May 1943:
Arrives at Kure.

1 June 1943:
Departs Kure for Saeki Gulf with I-8 and submarine tender HIE MARU.

2 June 1943:
Departs Saeki for Penang with I-8 and HIE MARU.

12 June 1943:
Arrives at Penang where I-10 is appointed flagship of SubRon 8 until 2 September.

27 June 1943:
At 1630, departs Penang with I-8 on her fourth war patrol with ComSubRon 8 Rear Admiral Ishizaki aboard.

1 July 1943:
I-10 refuels and replenishes I-8 at 4-53S, 87-20E.

6 July 1943:
I-10 refuels I-8 at at 22-25S, 76-15E. I-8 then detaches via the Cape of Good Hope for the German U-Boat base at Brest, France.

22 July 1943:
Gulf of Aden. I-10 sinks 7,634-ton Norwegian tanker ALCIDES enroute from the Abadan to Fremantle, Australia. Hit by two torpedoes, she sinks at 03S, 68E. I-10 comes alongside and takes ALCIDES’ master, radio officer and second mate on board. The captured officers are imprisoned and freed by the Americans on 29 August 1945.

4 August 1943:
Returns to Penang.

19 August 1943:
Rear Admiral (later Vice Admiral) Ichioka Hisashi (former CO of YURA) assumes command of SubRon 8 from Rear Admiral Ishizaki.

2 September 1943:
At 1600, I-10 departs Penang for the Indian Ocean with a five-man camera crew aboard on her fifth war patrol. The footage taken on this patrol is used for the propaganda film "Gochin!"(Sunk!). I-10 also carries an E14Y1 "Glen" floatplane to reconnoiter a suspected Allied air base on Perim Island.

14 September 1943:
SW of the Chagos Islands, Indian Ocean. I-10 torpedoes and sinks 6,361-ton Norwegian tanker BRAMORA at 06-00N, 67-00E that was enroute from Bandar Abbas, Arabia with oil for Melbourne, Australia.

20 September 1943:
At dawn, the "Glen" floatplane from I-10 piloted by Lt (jg) Yoshikawa Hajime conducts a flight over Perim Island, Strait of Mandeb. He reports that there are no airfields on the island. I-10 returns to the Gulf of Aden.

24 September 1943:
Gulf of Aden, 75 miles SE of Aden. Around 0200, I-10 sights 7,634-ton American "Liberty" ship ELIAS HOWE and starts a chase. At 0312, she fires two torpedoes at HOWE. One hits, killing two sailors in the engine room; a heavy fire breaks out and an SOS signal is transmitted. I-10 surfaces and fires another torpedo. 15 minutes after the second hit the explosives aboard the ship detonates and HOWE sinks by the stern at 11-40N, 44-35E. The survivors are rescued by British trawler HMS AIGLON (FY.1841) and a seaplane.

1 October 1943:
Gulf of Aden. Around 1630, I-10 sights an Allied convoy heading west at 10 knots, and starts a chase. Cdr Tonozuka fires three torpedoes at 4,836-ton Norwegian armed merchant STORVIKEN enroute from Mombasa for Aden with a cargo of coal. STORVIKEN takes two hits to starboard side and sinks by the stern at 11-43N, 48-07E. Two crewmen are taken aboard I-10 as POWs.

4 October 1943:
Gulf of Aden. Around 1610, the soundman on I-10 detects multiple propeller noises and soon thereafter a nine-strong convoy escorted by two destroyers is sighted (convoy AP-47 enroute from Aden to Abadan). I-10 commences a chase, surfacing after nightfall.

5 October 1943:
140 miles N of Cape Guardafui. At 0510, I-10 fires three torpedoes at overlapping targets from a distance of 6,340 yards and then dives to 390 feet to escape depth-charging. Three explosions and breaking-up noises are heard.

The 9,057-ton Norwegian armed tanker ANNA KNUDSEN, sailing with convoy AP-47, is hit by one torpedo to her starboard bow at 14-20N, 50-47E. As a result of serious flooding her master orders Abandon Ship. After the flooding is checked, the crew returns to the tanker. I-10 is briefly depth-charged and receives minor damage to the engine room. Cdr Tonozuka later claims three merchants as sunk.

24 October 1943:
NW of Addu Atoll. At 1125, I-10 fires two torpedoes at 4,533-ton British armed motor vessel CONGELLA (ex-MINDORO, ex-SAGAMI, ex-SECUNDUS) on a voyage from Calcutta to Durban with 8,700 tons of general cargo. Both miss; Cdr Tonozuka orders Battle-Surface. The gunners of I-10 open fire until a fire breaks out aboard CONGELLA and she is abandoned. She sinks at 01-02N, 71-14E; her wireless operator is taken prisoner, 25 crew and three gunners are lost. 37 survivors are later rescued by HM whaler OKAPI and two RAF "Catalina" flying boats.

30 October 1943:
Arrives at Penang.

5 November 1943:
Departs Penang for Singapore.

7 November 1943:
Arrives at Singapore.

7 December 1943:
Departs Singapore for Sasebo.

16 December 1943:
Arrives at Sasebo for repairs and overhaul.

1 January 1944:
I-10 is attached directly to the Sixth Fleet HQ.

18 January 1944:
Cdr Tonozuka is relieved by Cdr Nakajima Seiji (54)(former CO of I-155).

3 February 1944:
Departs Sasebo for Truk.

10 February 1944:
Arrives at Truk.

17-18 February 1944: American Operation "Hailstone" - The Attack on Truk:
Task Force 58's five fleet carriers and four light carriers, supported by six battleships, ten cruisers and 28 destroyers, launch air attacks on Japanese ships in the lagoon, airfields and shore installations. They sink 31 transports and 10 naval vessels (two cruisers, four destroyers and four auxiliary vessels), destroy nearly 200 aircraft and damage severely about 100 more.

I-10 sustains minor damage during the air raid; three sailors are killed and two wounded. Following the attack, I-10 sorties from Truk in an attempt to intercept the carriers of TF 58.

25 February 1944:
Departs Truk on her sixth war patrol to operate off the West Coast of the United States.

4 March 1944:
E of Mili. I-10 is damaged in a depth-charge attack and has to abort her patrol.

20 March 1944:
Arrives at Yokosuka for repairs. Probably at that time an E27 Type 3 radar detector and a new Type 3 sonar are installed.

9 May 1944:
Departs Yokosuka on her seventh war patrol to operate east of the Marshall Islands.

12 June 1944:
Marshall Islands. I-10's floatplane reconnoiters the American fleet anchorage at Majuro. The aircraft reports that the anchorage is empty. The landing floatplane capsizes and is lost.

13 June 1944: Operation "A-Go": The Defense of the Marianas:
In Tokyo, the CINC, Combined Fleet, Admiral Toyoda Soemu, (former CO of HYUGA), activates A-Go and orders Vice Admiral Takagi Takeo (former CO of MUTSU), CINC, Sixth Fleet (Submarines) to redeploy his boats to the Marianas from the area bounded by Palau, Mindanao and New Guinea.

From his Headquarters on Saipan, Takagi orders all 18 available submarines to deploy to the east of the Marianas.

15 June 1944: American Operation "Forager" - The Invasion of Saipan:
Vice Admiral (later Admiral) Richmond K. Turner's Task Force 52 lands Marine LtGen 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 Rear Admiral Owada Noboru (former CO of YAMASHIRO), ComSubRon 7 at Truk.

Admiral Owada orders most of the Sixth Fleet's submarines to withdraw from the Marianas area except I-10 and five others.

24 June 1944:
The Combined Fleet orders Owada to evacuate Vice Admiral Takagi and his staff from their headquarters on the eastern coast of Saipan. Owada orders I-10 located E of Saipan to breakthrough the cordon of American ships around Saipan and get Takagi and his people out. The rescue mission fails.

27 June 1944:
At 1200 (JST) I-10 transmits her position report from the area 40 miles NE from Saipan. This is the last message received from her.

2 July 1944:
Presumed lost off Saipan with all hands.

4 July 1944:
65 miles ENE of Saipan. At 1702 the TG 50.17 with six tankers and USS BRETON (CVE-23) is refueling at sea, when the soundman on LtCdr Roland H. Cramer’s USS RIDDLE (DE-185) detects an underwater contact bearing 250 degrees, range 1,900 yards. The Task Group Commander orders his formation to execute an emergency turn to port. After firing a five depth-charge urgent barrage RIDDLE commences a new approach, but the submarine foils her attack, turning into the wakes of the retiring formation.

Eighteen minutes later the contact is regained at 1,250 yards. Three patterns of "Hedgehog" projectiles are fired, but the submarine avoids being hit by diving deeper and maneuvering aggressively. At 1812, RIDDLE makes a depth-charge attack with a full pattern set deep without any results.

The estimated range, bearing and target course are passed to USS DAVID W. TAYLOR (DD-551), who makes a contact at 1822 and drops 11 depth charges set to medium depth. At 1828, RIDDLE is about to commence another attack, when a heavy underwater explosion occurs directly ahead. No further contacts are obtained.

By sundown, oil and debris break the surface at 15-26N, 147-48E. On the following day an oil slick is observed, stretching nine miles downwind from the point of attack.

10 October 1944:
Removed from the Navy List.

Authors' Notes:
[1] Several Japanese sources state that I-10 was launched on 20, rather than 29 September 1939. We have followed the authoritative "Showa Zosenshi" shipbuilding history in this case.

[2] A recent book dealing with the cryptoanalytic background of the Japanese attack on Pearl Harbor, suggests that I-10’s floatplane was lost at Pago Pago four days later. This is not confirmed by wartime records.

[3] Mt. Niitaka, located in Formosa (now Taiwan), is then the highest point in the Japanese Empire.

[4] Later, RAMILLIES returned to Plymouth, England where full repairs were completed from September 1942 to June 1943 and the following year participated in the D-Day invasion.

[5] A popular account of the sinking of EXPRESS suggests that immediately prior to the first torpedo hit she was illuminated by a starshell fired from the I-10. This must be incorrect, since I-10 attacked from the submerged position.

[6] Some survivors from ALCHIBA claimed that their ship was attacked and sunk by no less than two submarines; in fact only I-10 was involved.

[7] At that time the Pacific Theater C-in-C, Fleet Admiral Chester W. Nimitz and Secretary of the Navy Frank Knox participated in the COMSOPAC conference held on Noumea. Lt (jg) Sasakura evidently failed to detect any signs of that event.

Thanks go to Dr. Higuchi Tatsuhiro of Japan.

– Bob Hackett and Sander Kingsepp

Back to Submarine Page

Bob Hackett & Sander Kingsepp
Revision 5

25 January 1938:
Laid down at Kure Navy Yard.

20 May 1939:

20 December 1940:
Cdr Oyama Toyojiro (49) (former CO of I-15) is appointed Chief Equipping Officer.

13 February 1941:
Completed and attached to Yokosuka Naval District. Cdr Oyama is appointed CO.

31 July 1941:
Cdr Fujii Akiyoshi (49) (former CO of I-3) is appointed CO.

November 1941:
I-9 is assigned to Vice Admiral Shimizu Mitsumi's Advance Expeditionary Force (Sixth Fleet) as flagship of Rear Admiral Sato Tsutomu's SubRon 1's I-15 through I-26.

21 November 1941:
Departs Yokosuka with ComSubRon 1 RAdm Sato Tsutomu aboard in company of I-15, I-17 and I-25, carrying a Watanabe E9W1 "Slim" floatplane.

2 December 1941:
The coded signal "Niitakayama nobore (Climb Mt. Niitaka) 1208" is received from the Combined Fleet. It signifies that hostilities will commence on 8 December (Japan time). Mt. Niitaka, located in Formosa (now Taiwan), is then the highest point in the Japanese Empire.

7 December 1941: Operation "Z" - The Attack on Pearl Harbor:
Off Hawaii. I-9, with Rear Admiral Sato embarked, patrols north of Oahu during the attack on Pearl Harbor. Its mission is to reconnoiter and attack any ships that try to sortie from Pearl Harbor.

9 December 1941:
I-6 reports sighting a LEXINGTON-class aircraft carrier and two cruisers off Oahu heading ENE. Vice Admiral Shimizu in KATORI at Kwajalein orders all of SubRon 1's boats, except the Special Attack Force, to pursue and sink the carrier. I-9 surfaces and sets off at flank speed after the carrier.

11 December 1941:
700 miles NE of Oahu. At 1340, I-9 battle-surfaces on unarmed Matson Lines' steamer LAHAINA (ex-WEST CARMONA, ex-GOLDEN STATE) returning to Hawaii after the outbreak of war with 745 tons of molasses and 300 tons of scrap iron. After surfacing off LAHAINA's starboard quarter, the submarine first fires a warning shot. The crew abandons ship after transmitting an S.O.S. signal. Cdr Fujii fires no less than 25 shells for 12 hits (8 starboard, 4 port), setting the superstructure afire.

12 December 1941:
In the following morning, the crew attempts to reboard the ship, but the fires and flooding are out of control. LAHAINA explodes, capsizes to port and sinks around 1230 at 27-42N, 147-38W. Two LAHAINA sailors die of exposure, two commit suicide. Thirty survivors reach Kahului, Maui, on 21 December. [1]

13 December 1941:
The Imperial General Headquarters orders the IJN submarines to shell the US West Coast. VAdm Shimizu issues a detailed order on the targets. I-15, I-9, I-10, I-17, I-19, I-21, I-23, I-25 and I-26 are each to fire 30 shells on the night of 25 December. Rear Admiral Sato, aboard I-9, is charged to execute the order.

19 December 1941:
Arrives off Cape Blanco, Oregon.

22 December 1941:
Departs her patrol sector for Guadalupe Island area.

27 December 1941:
Most of the I-boats off the coast have depleted their fuel reserves. Vice Admiral Shimizu cancels the shelling.

1 January 1942:
Arrives at Kwajalein.

January 1942: Operation "K-1" - Flying Boat Attack on Pearl Harbor:
The Naval General Staff develops a plan to raid Pearl Harbor using two large Type 2 four-engined Kawanishi H8K1 Emily flying boat bombers. The objective of the attack is to disrupt ship repair activities. The plan calls for the planes to depart Wotje in the Marshalls and fly to French Frigate Shoals in the Hawaiian Islands (500 miles WNW of Pearl Harbor) where they are to be refueled by I-class submarines.

1 February 1942:
Kwajalein is attacked by planes from USS ENTERPRISE (CV-6). Two hours later, Headquarters Sixth Fleet orders I-9 and the other boats of SubRon 1 to put to sea and intercept the enemy carriers. After their return, I-9 departs that same day, carrying a E9W1 floatplane on her second war patrol.

5 February 1942:
At Kwajalein. Five submarines are selected to participate in Operation K-1. I-9 is assigned to take up station midway between Wotje and the Shoals and act as a radio beacon for the two H8K1 Emily flying boats. I-19, I-15 and I-26 are to refuel the flying boats at the Shoals. I-23 is to standby south of Hawaii, provide weather reports and act in an air-sea rescue capacity. The submarines depart for their stations.

7 February 1942:
Arrives to the area 200 miles S of Hawaii.

23 February 1942:
The E9W1 floatplane from I-9 conducts a nightly recce flight over Pearl Harbor. Due to limited visibility the pilot and observer cannot identify any ships in the harbor. During recovery after return, both wings of the plane are damaged.

28 February 1942:
Departs her patrol sector to participate in Operation K-1.

1 March 1942: The Second Air Attack on Pearl Harbor:
I-9 is on station and participates in Operation K-1.

4 March 1942:
After dark, the Emilys arrive at French Frigate Shoals, refuel and take off again for Pearl Harbor.

5 March 1942:
Seven hours after departing French Frigate Shoals, the flying boats drop eight 550-lb. bombs on Honolulu through an overcast. They achieve no significant results and return to the Marshall Islands.

13 March 1942:
I-9 acts as radio-beacon-cum-communications relay platform at Point M (19-00N, 174-20W).

16 March 1942:
Vice Admiral, the Marquis, Komatsu Teruhisa (former CO of CA NACHI) assumes command of the Sixth Fleet (Submarines).

21 March 1942:
Returns to Yokosuka.

15 May 1942:
Departs Yokosuka for Aleutians on her third war patrol, carrying an E14Y1 Type 0 Glen floatplane.

17 May 1942:
Arrrives at Ominato.

19 May 1942:
Departs Ominato to support the invasion of the Western Aleutians.

20 May 1942:
Reassigned to Northern District Force.

21 May 1942:
Rear Admiral (later Vice Admiral) Yamazaki Shigeaki's (former CO of old CA YAKUMO) SubRon 1's I-19, I-9, I-15, I-17, I-25 and I-26 is tasked to carry out preliminary invasion reconnaissance of the Aleutian Islands. I-9 departs Yokosuka for Kiska.

24 May 1942:
At dawn, I-9's E14Y1 floatplane reconnoiters Kiska and Amchitka, Aleutians. The pilot reports that Reynard Cove on Kiska is best suited for a future landing. No troops or barracks are sighted ashore. He also reports that contrary to the earlier reports there is no airfield on Amchitka.

26 May 1942:
Around 0500 (local), I-9's floatplane reconnoiters Adak and Kanaga. The pilot counts eight bivouacs and other similar buildings on Adak.

29 May 1942:
Provides distant cover for Rear Admiral Kakuta Kakuji's CarDiv 4.

5 June 1942: Operation "AL"- The Invasion of the Western Aleutians:
Twenty ships of the Vice Admiral Hosogaya Boshiro's (former CO of MUTSU) Fifth Fleet, including light cruisers KISO and TAMA, three destroyers, three corvettes, three minesweepers and four transports land Rear Admiral (later Vice Admiral) Omori Sentaro's (former CO of ISE) Occupation Force on Attu, Aleutians without opposition.

6 June 1942:
Joins a patrol line off Aleutians.

7 June 1942:
Captain (later Rear Admiral) Ono Takeji's Occupation Force occupies Kiska, also without opposition.

8 June 1942:
The patrol line is shifted to Kodiak area.

15 June 1942:
I-9's floatplane reconnoiters Kodiak Naval Air Station. On that same day, I-9 attacks two merchants in the same area, but misses both times.

19 June 1942:
I-9 shells and damages 4,636-ton American troop transport GENERAL W. C. GORGAS (former Hamburg-America Lines PRINZ SIGISMUND) at 56-17N, 146-46W.

30 June 1942:
Reassigned to Advance Force. Departs her patrol sector for Yokosuka.

7 July 1942:
I-9 arrives at Yokosuka.

7 August 1942: American Operation "Watchtower" - The Invasion of Guadalcanal, British Solomon Islands:
Rear Admiral (later Admiral) Richmond K. Turner's Amphibious Task Force 62, covered by Vice Admiral (later Admiral) Frank J. Fletcher's Task Force 61 and Rear Admiral (later Admiral) John S. McCain's Task Force 63's land-based aircraft, lands Maj Gen (later Gen/Commandant) Alexander A. Vandegrift's 1st Marine Division on Guadalcanal, opening a seven-month campaign to take the island.

15 August 1942:
Departs Yokosuka in company of I-15, I-17, I-19 and I-26 with ComSubRon 1 Rear Admiral Yamazaki Shigeaki aboard on her fourth war patrol.

23 August 1942:
I-9 joins the patrol line A off San Cristobal..

24 August 1942: The Battle of the Eastern Solomons:
Vice Admiral (later Admiral) Frank J. Fletcher's Task Force 61's USS SARATOGA (CV-3) and ENTERPRISE (CV-6) launches aircraft that find and sink the light carrier RYUJO. In turn, CarDiv 1's SHOKAKU and ZUIKAKU launch aircraft that find and damage ENTERPRISE. That evening, aircraft from SARATOGA damage seaplane carrier CHITOSE.

25 August 1942:
At 1143, LtCdr Frederick Bell's USS GRAYSON (DD-435), temporarily screening Fletcher's TF 11, spots a "carrier's superstructure" 12 miles WSW. The destroyer is detached to investigate the contact, two minutes later identified as a diving submarine.

At 1223, GRAYSON commences a depth-charge attack, but I-9 foils her approach, turning inside the destroyer's turning circle. After the contact is reestablished, GRAYSON makes another attack, but again I-9 escapes with a hard turn at full speed at the depth of 200 feet.

LtCdr Bell, joined by a Douglas SBD "Dauntless" dive-bomber from USS WASP, conducts a dummy attack to wear the submarine down. After 1329, GRAYSON drops the third pattern of depth charges. I-9 heads due west at 4 knots and the contact is lost until 1347. Meanwhile PATTERSON (DD-392) joins the hunt.

At 1351, GRAYSON commences the fourth attack, but I-9 turns to WSW, making 7 knots. With the fifth attack the destroyer expends her entire supply of depth charges, slowing the submarine down to 4 knots. Buffeted by close explosions, I-9 drops to 440 feet; all lights go out and a small leak appears in one of the forward fuel tanks. Aft bilge pump is disabled.

At 1418, PATTERSON commences her first run, but fails to detect the target in the turbulence created by GRAYSON's depth charges. 1438, USS MONSSEN (DD-436) joins the hunt.

At 1440, PATTERSON establishes sonar contact with the submarine; a few minutes later her lookouts report the submarine is surfacing. The "Dauntless" marks its location with a smoke float. PATTERSON and MONSSEN make one attack each. After a huge air bubble and oil slick appear, the destroyers depart the area, claiming their target as sunk.

I-9 surfaces two hours after the last attack. An inspection reveals some additional damage: two periscopes are rendered inoperable and one radio transmitter temporarily knocked out. Rear Admiral Yamazaki reports the damage to Truk and is ordered to return to base.

30 August 1942:
Arrives at Truk. Undergoes repairs by URAKAMI MARU.

8 September 1942:
Departs Truk for an area SE of Guadalcanal on her fifth war patrol with ComSubRon 1 embarked.

15 September 1942:
Cdr Fujii sights several transports. On that same day, I-9 is reassigned to 2nd Patrol Unit.

23 September 1942:
200 miles SE of Guadalcanal. I-9 briefly chases a transport escorted by one destroyer.

1 October 1942:
Departs her patrol sector for Truk.

6 October 1942:
Arrives at Truk.

13 October 1942:
The staff of ComSubRon 1 is transferred ashore.

16 October 1942:
Departs Truk on her sixth war patrol SE of the Solomons, carrying an E14Y1 floatplane. Reassigned to the "B" Patrol Unit.

31 October 1942:
Reassigned to B Patrol Unit. Ordered to reconnoiter Nouméa, New Caledonia.

4 November 1942:
I-9's floatplane reconnoiters Nouméa airfield and harbor, sighting one aircraft carrier, three cruisers and several smaller vessels.

7 November 1942:
I-9 is detached from B Patrol Unit to conduct aerial reconnaissance of Espiritu Santo instead of I-7.

11 November 1942:
I-9 is ordered to proceed to Shortland.

12 November 1942:
I-9's floatplane reconnoiters Espiritu Santo, but as a result of dense cloud cover no ships can be observed.

16 November 1942:
Truk. Vice Admiral Komatsu convenes a meeting of his submarine captains. He announces that the Sixth Fleet has been ordered by Admiral Yamamoto, CINC, Combined Fleet to organize a supply system for the IJA's 17th Army garrison on Guadalcanal.

19 November 1942:
Arrives at Shortland, embarks cargo.

24 November 1942:
Departs Shortland on her first supply run to Kamimbo Bay, NW Guadalcanal, carrying 32 tons of food and ammunition.

26 November 1942:
Arrives at Kamimbo, unloads her cargo, then departs for Truk.

1 December 1942:
Arrives at Truk.

Late December 1942:
Departs Truk for Shortland.

2 January 1943:
Arrives at Shortland.

4 January 1943:
Departs Shortland on her second supply run to Guadalcanal, carrying 21 tons of food in rubber containers.

6 January 1943:
Arrives at Kamimbo, unloads her cargo, then departs for Shortland.

8 January 1943:
Returns to Shortland.

10 January 1943:
Departs Shortland on her third supply run to Guadalcanal.

12 January 1943:
Arrives off Kamimbo, but fails to deliver her cargo, since the anchorage is patrolled by torpedo boats.

14 January 1943:
Returns to Shortland.

16 January 1943:
Departs Shortland on her fourth supply run to Guadalcanal.

18 January 1943:
Arrives off Kamimbo, but cannot release her supply drums underwater.

20 January 1943:
Returns to Shortland.

22 January 1943:
Departs Shortland on her fifth supply run to Guadalcanal, carrying 18 tons of cargo in 120 supply drums.

25 January 1943:
Arrives off Kamimbo, releases 80 supply drums with 12 tons of cargo, but is then driven away by torpedo boats.

27 January 1943:
Returns to Shortland.

28 January 1943:
Departs Shortland on her sixth supply run to Guadalcanal.

30 January 1943:
Arrives off Kamimbo, releases all supply drums, but all are detected and destroyed by arriving torpedo boats.

31 January 1943: Operation "KE" - The Evacuation of Guadalcanal:
A task force of units of the Second and Third Fleets from Truk including carriers ZUIKAKU, ZUIHO and JUNYO, Bat Div 3's KONGO and HARUNA, CruDiv 4's ATAGO and TAKAO, CruDiv 5's HAGURO and MYOKO, DesRon 4's light cruiser NAGARA, DesRon 10's light cruiser AGANO and destroyers, steams north of the Solomons as a feint to cover Rear Admiral (later Vice Admiral) Hashimoto Shintaro's (former CO of HYUGA) destroyer force from Rabaul.

1 February 1943:
Returns to Shortland, departs for Truk on that same day.

4 February 1943:
Arrives at Truk.

5 February 1943:
Departs Truk for Yokosuka.

9 February 1943:
The Japanese successfully complete the evacuation of 11,700 troops from Guadalcanal.

12 February 1943:
Arrives at Yokosuka.

20 February 1943:
Transferred from Yokosuka to Kawasaki's Kobe Yard for repairs. [2]

1 May 1943:
Cdr Fujii is promoted Captain.

11 May 1943: American Operation "Landcrab"- The Invasion of Attu, Aleutians:
Rear Admiral (later Admiral) Thomas C. Kinkaid's Task Force 16, covered by Rear Admiral Francis W. Rockwell's Task Force 51, lands the Army's 7 th Division that captures Attu.

12 May 1943:
Reassigned to Northern District Force.

13 May 1943:
Returns to Kure.

14 May 1943:
Departs Kure for Yokosuka, arriving on 16th.

21 May 1943: Operation "KE-Go" - The Evacuation of Kiska:
The Imperial General Headquarters decides to evacuate the garrison at Kiska Island, Aleutians.

23 May 1943:
Departs Yokosuka for Paramushiro Island in the Kuriles.

27 May 1943:
Arrives at Paramushiro.

29 May 1943:
Departs Paramushiro on her first supply run to Kiska, carrying 17 tons of ammunition and 2 tons of food.

1 June 1943:
Bering Sea, off Agattu. I-9 is chased by an unidentified destroyer for three hours.

2 June 1943:
Arrives at Kiska, unloads her cargo and departs on that same day, carrying 79 passengers (55 sailors, 10 soldiers and 10 gunzoku construction workers).

8 June 1943:
Returns to Paramushiro.

10 June 1943:
Departs Paramushiro for Kiska on her second supply run to that location to evacuate the personnel of the local midget base. No messages are received from I-9 thereafter.

13 June 1943:
Kiska, 15 miles E of Sirius Point. At 1758 LtCdr (later RAdm) Elliot M. Brown's USS FRAZIER (DD-607) detects a target with her radar 6,900 yards away. FRAZIER closes the range in dense fog at 20 knots and soon establishes sonar contact with a submarine. At 2009 a lookout sights two periscopes at 100 yds.

FRAZIER opens fire on the submarine, scoring a hit on one periscope. The destroyer attacks I-9 with depth charges. Air bubbles, oil and debris rise to the surface, but FRAZIER makes two more attacks to ensure that the submarine is sunk. I-9 is lost with all hands at 52-08N, 177-38E. [3]

15 June 1943:
Presumed lost lost with all 101 hands off Kiska. Captain Fujii is promoted to Rear Admiral posthumously on this date.

1 August 1943:
Removed from the Navy List.

Authors' Note:
[1] One source claims that on 9 December LAHAINA had been detected by a floatplane, probably an E14Y1 Type 0 launched from I-9. This is incorrect: no aircraft were launched from submarines on that day, nor were any E14Y1s embarked by that time.

[2] On 11 April 1943, USS TUNNY (SS-282) attacked a Japanese submarine it identified as I-9 off Truk. Since I-9 was nowhere near Truk at that time, this could only have been a mistake. In all likelihood, TUNNY 's adversary was I-16.

[3] USS FRAZIER’s victim was first identified as I-31 in Morison's "History of United States Naval Operations in World War II,” but this is incorrect: I-31 had already been lost a month before off Attu.

Thanks go to Dr. Higuchi Tatsuhiro of Japan.

– Bob Hackett & Sander Kingsepp

Back to Submarine Page