View source for Japanese submarine I-10

{{Short description|Imperial Japanese Navy Type A1 submarine}}
{|{{Infobox ship begin}}
{{Infobox ship image
|Ship image=Japanese submarine I-10 at Penang port in 1942.jpg
|Ship caption=''I-10'' at Penang in&nbsp;1942.
}}
{{Infobox ship career
|Hide header=
|Ship country=[[Empire of Japan]]
|Ship flag={{Shipboxflag|Empire of Japan|naval}}
|Ship name=''I-10''
|Ship namesake=
|Ship ordered=
|Ship builder=[[Kawasaki Shipbuilding Corporation|Kawasaki]], [[Kobe]]
|Ship laid down=7 June 1938
|Ship launched=20 or 29 September 1939 (see&nbsp;text)
|Ship commissioned=31 October 1941
|Ship fate=Sunk 4 July 1944
}}
{{Infobox ship career
|Hide header=yes
|Ship struck=10 October 1944
|Ship notes=
}}
{{Infobox service record
|is_ship=yes
|is_multi=yes
| partof = 
| codes =
| commanders = 
*Kayahara Yasuchika<ref name="ijnsubsiteI10" />
*31 October 1941 – 15 September 1942
*Yamada Takashi
*15 September 1942 – 15 April 1943
*Tonozuka Kinzo
*15 April 1943 – 18 January 1944
*Nakajima Seiji
*18 January 1944 – 4 July 1944
| operations =
| victories =
| awards =
}}
{{Infobox ship characteristics
|Hide header=
|Header caption=
|Ship class=[[Type A1 submarine]]
|Ship displacement=*{{Convert|2919|LT|t|0|disp=flip}} surfaced
*{{Convert|4129|LT|t|0|disp=flip}} submerged
|Ship length={{convert|113.7|m|ftin|abbr=on}} overall
|Ship beam= {{convert|9.5|m|ftin|abbr=on}}
|Ship draft={{convert|5.3|m|ftin|abbr=on}}
|Ship power=*{{convert|12400|bhp|lk=in|abbr=on}} (diesel)
*{{convert|2400|hp|abbr=on}} ([[electric motor]])
|Ship propulsion=*[[Diesel-electric]]
*1 × [[diesel engine]]
*1 × electric motor
|Ship speed=*{{convert|23.5|kn|lk=in}} surfaced
*{{convert|8|kn}} submerged
|Ship range=*{{convert|16000|nmi|abbr=on|lk=in}} at {{convert|16|kn}} surfaced
*{{convert|60|nmi|abbr=on}} at {{convert|3|kn}} submerged
|Ship crew=100
|Ship test depth={{convert|100|m|ft|abbr=on}}
|Ship armament=*6 × bow {{convert|533|mm|in|0|abbr=on}} [[torpedo tubes]]
*1 × [[14 cm/40 11th Year Type naval gun|{{convert|14|cm|in|1|abbr=on}}]] [[deck gun]]
*2 × twin [[Type 96 25 mm AT/AA Gun|{{convert|25|mm|in|0|abbr=on}} Type 96]] [[anti-aircraft gun]]s
|Ship aircraft=1 × [[Yokosuka E14Y]] seaplane
|Ship aircraft facilities=1 × [[Aircraft catapult|catapult]]
|Ship notes=
}}
|}
'''''I-10''''' was an [[Imperial Japanese Navy]] [[Type A1 submarine|Type A1]] [[submarine]] that served during [[World War II]]. Designed as a [[submarine aircraft carrier]], she was commissioned in 1941 and supported the [[attack on Pearl Harbor]], operated in the [[Indian Ocean]] — including support for the 1942 [[midget submarine]] attack on [[Antsiranana|Diego Suarez]] — and in the [[New Caledonia]] and [[New Zealand]] areas, and took part in the [[Guadalcanal campaign]] and [[Mariana and Palau Islands campaign|Marianas campaign]] before she was sunk in 1944 during her seventh war patrol.

==Design and description==
Type A1 submarines were versions of the preceding [[Type J3 submarine|Type J3]] with superior range and an improved aircraft installation, and they were fitted as [[Squadron (naval)|squadron]] [[flagship]]s.<ref name=b4/> They [[Displacement (ship)|displaced]] {{Convert|2919|LT|t|0|disp=flip}} on the surface and {{Convert|4129|LT|t|0|disp=flip}} submerged. The submarines were {{convert|113.7|m|ftin|sp=us}} long and had a [[Beam (nautical)|beam]] of {{convert|9.5|m|ftin|sp=us}} and a [[Draft (hull)|draft]] of {{convert|5.3|m|ftin|sp=us}}. They had a diving depth of {{convert|100|m|ft|0|sp=us}}.<ref name=b4>Bagnasco, p. 188</ref>

For surface running, Type A1 submarines were powered by two {{convert|6200|bhp|lk=in|0|adj=on}} [[diesel engine]]s, each driving one [[propeller shaft]]. When submerged each propeller was driven by a {{convert|1200|hp|0|adj=on}} [[electric motor]]. They could reach {{convert|19|kn|lk=in}} on the surface<ref name=c5>Chesneau, p. 200</ref> and {{convert|8.25|kn}} underwater. On the surface, the Type A1s had a range of {{convert|16000|nmi|sigfig=3|lk=in}} at {{convert|16|kn}}; submerged, they had a range of {{convert|90|nmi|abbr=on}} at {{convert|3|kn}}.<ref name=cd3/>

Type A1 submarines were armed with four internal [[Bow (ship)|bow]] {{convert|53.3|cm|in|1|abbr=on|sp=us}} [[torpedo tube]]s and carried a total of 18 [[torpedo]]es. They were also armed with a single [[14 cm/40 11th Year Type naval gun|{{convert|140|mm|in|1|abbr=on}}/40]] [[deck gun]] and two twin [[Type 96 25 mm AT/AA Gun|{{convert|25|mm|in|0|abbr=on}} Type 96]] [[anti-aircraft gun]]s.<ref name=cd3>Carpenter & Dorr, p. 101</ref>

Unlike on the Type J3 submarines, the aircraft [[hangar]] was integrated into the [[conning tower]] and faced forward, and the [[aircraft catapult]] was forward of the hangar, while the deck gun was aft of the conning tower. Reversing the locations of the deck gun and catapult allowed aircraft launching from a Type A1 submarine to use the forward motion of the submarine to supplement the speed imparted by the catapult.<ref name=cd3/>

==Construction and commissioning==

Built by [[Kawasaki Shipbuilding Corporation|Kawasaki]] at [[Kobe]], [[Japan]], ''I-10'' was [[Keel-laying|laid down]] as '''''Submarine No. 10''''' on 7 June 1938.<ref name=combinedfleetI10>{{cite web |url= http://www.combinedfleet.com/I-10.htm |title=IJN Submarine I-10: Tabular Record of Movement |first1=Bob |last1=Hackett |first2=Sander |last2=Kingsepp |work=combinedfleet.com |date=March 18, 2017|access-date=21 December 2021}}</ref> Later renamed '''''I-10''''', she was [[Ceremonial ship launching|launched]] on 20 or 29 September 1939, according to different sources,<ref name=combinedfleetI10/> and was completed and [[Ship commissioning|commissioned]] on 31 October 1941.<ref name=combinedfleetI10/>

==Service history==

===Pre-World War II===
On the day of her commissioning, ''I-10'' was attached to the [[Sasebo Naval District]] and assigned to Submarine [[Squadron (naval)|Squadron]] 2 in the [[6th Fleet (Imperial Japanese Navy)|6th Fleet]].<ref name=combinedfleetI10/> By 10 November 1941, she was serving as the squadron's [[flagship]].<ref name=combinedfleetI10/> That day, the 6th Fleet commander, [[Vice Admiral]] [[Mitsumi Shimizu]], held a meeting with the [[commanding officer]]s of the submarines of Submarine Squadron 3 aboard his flagship, the [[light cruiser]] {{ship|Japanese cruiser|Katori||2}}, and his chief of staff briefed them on plans for Operation Z, the upcoming surprise [[attack on Pearl Harbor]] in [[Hawaii]].<ref name=combinedfleetI10/> The attack would begin the [[Pacific War|Pacific campaign]] and bring Japan and the [[United States]] into [[World War II]].<ref name=combinedfleetI10/> ''I-10'' and the submarine {{ship|Japanese submarine|I-26||2}} were assigned to the 6th Fleet Reconnaissance Unit.<ref name=combinedfleetI10/>

As Japanese military forces began to deploy for the opening Japanese offensive of the war, ''I-10'', with an embarked [[Watanabe E9W]]1 ([[World War II Allied names for Japanese aircraft|Allied reporting name]] "Slim") [[floatplane]], departed [[Yokosuka]], Japan, on 16 November 1941, with orders to conduct a reconnaissance of areas in the vicinity of [[Fiji]] and the [[Samoan Islands]], including [[Tutuila]] in [[American Samoa]].<ref name=combinedfleetI10/> She arrived at [[Kwajalein Atoll]] in the [[Marshall Islands]] on 23 November 1941 to refuel, then proceeded to Fijian waters.<ref name=combinedfleetI10/> Off [[Viti Levu]] in the Fiji Islands on 30 November 1941, she launched her floatplane to reconnoiter [[Suva Bay]] off [[Suva]].<ref name=combinedfleetI10/><ref name=prange431>Prange, Gordon W., "At Dawn We Slept: The Untold Story of Pearl Harbor", Penguin Books, New York, New York, 1981, Library of Congress card number 82-5896, {{ISBN|0-14-00-6455-9}}, page 431.</ref> The floatplane′s crew reported sighting no enemy ships at Suva Bay, but it never returned to ''I-10'', and after a fruitless three-day search for it and its crew under radio silence, ''I-10'' gave up the search and reported the loss of her plane and its crew to 6th Fleet headquarters.<ref name=combinedfleetI10/><ref name=prange431/>

While ''I-10'' was at sea, she received the message "Climb [[Yu Shan|Mount Niitaka]] 1208" ({{langx|ja|Niitakayama nobore 1208}}) from the [[Combined Fleet]] on 2 December 1941, indicating that war with the [[Allies of World War II|Allies]] would commence on 8 December 1941 [[Japan Standard Time|Japan time]], which was on 7 December 1941 on the other side of the [[International Date Line]] in [[Hawaii]].<ref name=combinedfleetI10/> On 3 December 1941, she conducted a submerged reconnaissance of the harbor at [[Pago Pago]] on Tutuila in American Samoa, sighting what she identified as a [[United States Navy]] "[[New Orleans-class cruiser|''Astoria''-class]]" [[heavy cruiser]].<ref name=combinedfleetI10/>

===World War II===

====First war patrol====

Heading toward Hawaii after leaving the waters around American Samoa, ''I-10'' arrived in a patrol area {{convert|1,300|nmi}} south of [[Oahu]] on 7 December 1941, the day the Japanese attacked Pearl Harbor.<ref name=combinedfleetI10/> On 9 December, she received a report that the submarine {{ship|Japanese submarine|I-18||2}} had sighted the U.S. Navy [[aircraft carrier]] {{USS|Lexington|CV-2}}, along with orders to leave her patrol area and join the search for ''Lexington''.<ref name=combinedfleetI10/> While {{convert|700|nmi}} southeast of Hawaii after dark that evening, she fired one [[torpedo]] at the [[Panama]]nian 4,430-[[gross register ton]] [[motor vessel]] {{MV|Donerail||2}}, which was on a voyage from Suva to [[Vancouver]], [[British Columbia]], [[Canada]], with a cargo of [[sugar]] and [[pineapple]]s.<ref name=combinedfleetI10/><ref name=edwardsp4>Edwards, p. 4.</ref> After the torpedo missed, she surfaced and attacked ''Donerail'' with gunfire, firing twenty {{convert|140|mm|in|1|adj=on|sp=us}} rounds.<ref name=combinedfleetI10/> As ''Donerail''′s crew abandoned ship, one shell struck her [[Port and starboard|starboard]] [[Lifeboat (shipboard)|lifeboat]] while it still hung in its [[davit]]s, completely destroying it and killing everyone in it.<ref name=combinedfleetI10/> ''Donerail'' sank two hours later at {{coord|08|N|152|W|name=MV ''Donerail''}}.<ref name=combinedfleetI10/> Meanwhile, ''I-10''′s crew opened [[machine gun]] fire on her survivors.<ref>Edwards, pp. 4, 230.</ref> Twenty-seven of ''Donerail''′s passengers and crew died in the sinking and subsequent massacre,<ref>Edwards, p. 230.</ref> leaving only 16 alive.<ref name=edwardsp4/> Of the 42 people aboard ''Donerail'', only eight ultimately survived, reaching [[Tarawa]] in the [[Gilbert Islands]] 38 days later.<ref name=combinedfleetI10/>

On 12 December 1941, ''I-10'' was reassigned to the Advance Force, and that day she received orders to proceed to the [[United States West Coast]] and patrol in an area off [[San Diego]], [[California]].<ref name=combinedfleetI10/> On 13 December 1941, Japanese [[Imperial General Headquarters]] ordered the submarines of the 6th Fleet to bombard the U.S. West Coast.<ref name=combinedfleetI9>{{cite web |url= http://www.combinedfleet.com/I-9.htm |title=IJN Submarine I-9: Tabular Record of Movement |first1=Bob |last1=Hackett |first2=Sander |last2=Kingsepp |work=combinedfleet.com |date=August 1, 2016|access-date=17 December 2021}}</ref> On 14 December 1941, the 6th Fleet′s commander, [[Vice admiral|Vice Admiral]] [[Mitsumi Shimizu]], in turn ordered ''I-10'' and the submarines {{ship|Japanese submarine|I-9||2}}, ''I-15'', ''I-17'', {{ship|Japanese submarine|I-19||2}}, {{ship|Japanese submarine|I-21||2}}, {{ship|Japanese submarine|I-23||2}}, ''I-25'', and {{ship|Japanese submarine|I-26||2}} each to fire 30 rounds at targets on the U.S. West Coast on the evening of 25 December 1941, with the commander of Submarine [[Squadron (naval)|Squadron]] 1, [[Rear admiral|Rear Admiral]] [[Tsutomu Sato (admiral)|Tsutomu Sato]]. aboard ''I-9'' in overall command of the bombardment.<ref name=combinedfleetI9/> On 22 December 1941 the [[commander-in-chief]] of the [[Combined Fleet]], Admiral [[Isoroku Yamamoto]], postponed the bombardment until 27 December.<ref>{{cite web |url= http://www.combinedfleet.com/I-26.htm |title=IJN Submarine I-26: Tabular Record of Movement |first1=Bob |last1=Hackett |first2=Sander |last2=Kingsepp |work=combinedfleet.com |date=March 1, 2016|access-date=20 February 2022}}</ref> On 27 December 1941, Sato cancelled the bombardment because most of the submarines tasked with carrying it out were low on fuel.<ref name=combinedfleetI9/> ''I-10''′s time off the U.S. West Coast otherwise passed quietly. On 9 January 1942 she was reassigned directly to 6th Fleet headquarters, and on 11 January 1942 she arrived at Kwajalein.<ref name=combinedfleetI10/>

====January–April 1942====

After an overnight stay at Kwajalein, ''I-10'' departed on 12 January 1942 bound for Yokosuka, which she reached on 21 January 1942.<ref name=combinedfleetI10/> While in Japan, she was reassigned to Submarine Squadron 8 on 10 March 1942.<ref name=combinedfleetI10/> On 12 March, she got underway from Yokosuka to search for and attack the aircraft carriers of U.S. Navy [[Task Force 17]], which had conducted the [[Lae-Salamaua Raid]] against Japanese forces landing on the northeast coast of [[New Guinea]] on 10 March, but she had no success, and she returned to Japan, arriving at [[Kure]] on 20 March 1942.<ref name=combinedfleetI10/>

During ''I-10''′s stay in Japan, the [[Kriegsmarine|German naval staff]] in [[Berlin]] formally requested on 27 March 1942 that Japan begin attacks on [[Allies of World War II|Allied]] [[convoy]]s in the [[Indian Ocean]].<ref name=combinedfleetI10/> On 8 April 1942, the Japanese formally agreed to meet this request by dispatching submarines to operate off the coast of [[East Africa]],<ref name=combinedfleetI20>{{cite web |url= http://www.combinedfleet.com/I-20.htm |title=IJN Submarine I-20: Tabular Record of Movement |first1=Bob |last1=Hackett |first2=Sander |last2=Kingsepp |work=combinedfleet.com |year=2017|access-date=19 August 2020}}</ref> and that day they withdrew Submarine Division 1 of [[8th Submarine Squadron (Imperial Japanese Navy)|Submarine Squadron 8]] from its base at Kwajalein to Japan.<ref name=combinedfleetI18>{{cite web |url= http://www.combinedfleet.com/I-18.htm |title=IJN Submarine I-18: Tabular Record of Movement |first1=Bob |last1=Hackett |first2=Sander |last2=Kingsepp |work=combinedfleet.com |year=2017|access-date=19 August 2020}}</ref> By 16 April 1942 they had created the "A" detachment within Submarine Squadron 8, consisting of ''I-10'' and the submarines {{ship|Japanese submarine|I-16||2}}, {{ship|Japanese submarine|I-18||2}}, {{ship|Japanese submarine|I-20||2}}, and  {{ship|Japanese submarine|I-30||2}}, as well as [[midget submarine]]s and the [[auxiliary cruiser]]s {{ship||Aikoku Maru|1940|2}} and {{ship||Hōkoku Maru||2}}, which were to operate as supply ships for the submarines.<ref name=combinedfleetI10/> That morning, the commander of the 6th Fleet, [[Vice Admiral]] [[Teruhisa Komatsu]], the commander of Submarine Squadron 8, their staffs, and the midget submarine crews paid a courtesy call on Admiral Yamamoto aboard his flagship, the [[battleship]] {{ship|Japanese battleship|Yamato||2}}, at [[Hashira Island|Hashirajima anchorage]].<ref name=combinedfleetI10/> After the visit with Yamamoto, the detachment got underway at 11:00, bound for [[Penang Island|Penang]] in Japanese-occupied [[British Malaya]].<ref name=combinedfleetI10/>

During the detachment′s voyage, 16 [[United States Army Air Forces]] [[North American B-25 Mitchell|B-25 Mitchell]] [[bomber]]s launched by the aircraft carrier {{USS|Hornet|CV-8}} struck targets on [[Honshu]] in the [[Doolittle Raid]] on 18 April 1942.<ref name=combinedfleetI16>{{cite web |url= http://www.combinedfleet.com/I-16.htm |title=IJN Submarine I-16: Tabular Record of Movement |first1=Bob |last1=Hackett |first2=Sander |last2=Kingsepp |work=combinedfleet.com |date=July 20, 2017|access-date=19 August 2020}}</ref> The detachment received orders from the 6th Fleet that day to divert from its voyage and head northeast, passing north of the [[Bonin Islands]], to intercept the U.S. Navy [[task force]] that had launched the strike.<ref name=combinedfleetI16/> The detachment failed to find the U.S. ships and soon resumed its voyage.

''I-30'' and ''Aikoku Maru'' called at Penang from 20 April to 22 April 1942 before heading into the Indian Ocean to conduct an advance reconnaissance of the "A" Detachment′s planned operating area.<ref name=combinedfleetI30>{{cite web |url= http://www.combinedfleet.com/I-30.htm |title=IJN Submarine I-30: Tabular Record of Movement |first1=Bob |last1=Hackett |first2=Sander |last2=Kingsepp |work=combinedfleet.com |year=2012|access-date=18 August 2020}}</ref> ''I-10'' made an overnight stop at [[Singapore]] from 23 to 24 April, then proceeded to Penang. The [[Imperial Japanese Army]] [[Transport (ship)|transport]] ''Urajio Maru'' mistakenly opened gunfire on her during her voyage, but she avoided damage and arrived at Penang safely on 25 April 1942.<ref name=combinedfleetI10/> On 27 April, the rest of the "A" Detachment arrived at Penang, where the [[seaplane carrier]] {{ship|Japanese seaplane carrier|Nisshin||2}} — which had undergone modifications allowing her to carry Type A midget submarines — rendezvoused with it.<ref name=combinedfleetI16/> ''I-16'', ''I-18'', and ''I-20'' each embarked a midget submarine at Penang on 30 April 1942.<ref name=combinedfleetI16/>

====Indian Ocean operation====

''I-10'' and the other "A" detachment units got underway from Penang on 30 April 1942, headed westward into the Indian Ocean with ''I-10'' serving as the detachment′s flagship.<ref name=combinedfleetI16/> The submarines [[Underway replenishment|refueled at sea]] from ''Aikoku Maru'' and ''Hōkoku Maru'' on 5, 10, and 15 May 1942.<ref name=combinedfleetI16/>

''I-10''′s [[Yokosuka E14Y]]1 (Allied reporting name "Glen") floatplane began reconnaissance flights over ports in [[South Africa]] by reconnoitering [[Durban]] on 20 May 1942,<ref name=combinedfleetI10/><ref name=combinedfleetI20/><ref name=combinedfleetI16/> where its crew found no targets of importance. Although challenged from the ground during the flight, the aircraft escaped after its radioman bought time by transmitting a false recognition signal in response.<ref name=combinedfleetI10/> The plane made flights over [[East London, Eastern Cape|East London]], [[Port Elizabeth]], and [[Simon's Town]] over the next week,<ref name=combinedfleetI20/> and by 24 May the "A" detachment submarines were encountering heavy Allied shipping traffic as they approached [[East Africa]].<ref name=combinedfleetI20/> On the night of 29 May, ''I-10''′s floatplane flew over [[Antsiranana|Diego-Suarez]], [[Madagascar]], sighting the British battleship {{HMS|Ramillies|07|6}} among the ships [[anchor]]ed there.<ref name=combinedfleetI16/> The "A" detachment commander selected Diego-Suarez as the target for a midget submarine attack, scheduled for 30 May 1942.<ref name=combinedfleetI16/>

On 30 May 1942, ''I-18''′s midget submarine could not launch because of engine failure,<ref name=combinedfleetI18/> but ''I-16'' and ''I-20'' both launched their midget submarines to [[Battle of Madagascar#Landings (Operation Ironclad)|attack the Allied warships at Diego Suarez]].<ref name=combinedfleetI16/><ref name=combinedfleetI20/><ref name="Rigge107">Rigge, Simon (1980). ''War in the Outposts''. Chicago, Time-Life Books, pp. 107–108,</ref> ''I-20''′s midget submarine, ''M-20b'', managed to enter the harbor and was attacked with depth charges, but fired two torpedoes. One torpedo seriously damaged ''Ramillies'', while the second sank the 6,993-ton [[oil tanker]] ''British Loyalty''.<ref name=combinedfleetI10/><ref name=combinedfleetI20/><ref name="Rigge107"/> ''Ramillies'' required repairs in South Africa and [[England]].<ref name="Rigge107"/> Neither midget submarine returned, and on 31 May 1942, ''I-10''′s floatplane made a flight over Diego Suarez in the hope of locating any of the midget submarine crewmen who might have reached shore, without success.<ref name=combinedfleetI10/> ''I-16''′s midget submarine disappeared at sea and the body of one of its crewman was found washed ashore on Madagascar on 31 May.<ref name=combinedfleetI16/><ref name="Rigge107"/> The crew of ''M-20b'' beached their craft at [[Nosy Antalikely]] and moved inland towards a pre-arranged pick-up point near [[Cape Amber]], but were both killed in a firefight with British [[Royal Marines]] on 2 June 1942; one Marine was killed in the action as well.<ref name=combinedfleetI20/><ref name="Rigge107"/>

After the midget submarine attack, the "A" detachment began anti-shipping operations in the Indian Ocean.<ref name=combinedfleetI10/> ''I-10'' had her first success at 02:31 on 5 June 1942 when she sank the 2,639-gross register ton Panamanian [[Steamship|steamer]] {{SS|Atlantic Gulf}} in the [[Mozambique Channel]] {{convert|350|nmi}} east of [[Beira, Mozambique|Beira]], [[Portuguese East Africa]], at {{coord|21|03|S|037|36|E|name=SS ''Atlantic Gulf''}}.<ref name=combinedfleetI10/> Later that day, she sank the American 4,999-gross register ton armed [[cargo ship]] {{SS|Melvin H. Baker}} at {{coord|21|44|S|036|38|W|name=SS ''Melvin H. Baker''}};<ref name=combinedfleetI10/> the British steamer {{SS|Twickenham}} rescued ''Melvin H. Baker''′s crew.<ref name=combinedfleetI10/> Again in the Mozambique Channel {{convert|350|nmi}} east of Beira, she torpedoed the 5,224-gross register ton British steamer {{SS|King Lud}} — which was on a voyage from [[New York City]] to [[Bombay]] in [[British India]] with a stop at [[Cape Town]], South Africa, carrying military personnel and government stores — at 09:53 on 8 June 1942;<ref name=combinedfleetI10/> ''King Lud'' sank at {{coord|20|S|40|E|name=SS ''King Lud''}}, with no survivors.<ref name=combinedfleetI10/>

''Aikoku Maru'' and ''Hōkoku Maru'' refueled and replenished ''I-10'' on 17 June 1942.<ref name=combinedfleetI10/> Returning to action, she torpedoed the 4,957-gross register ton British [[motor vessel]] {{MV|Queen Victoria}} — which was on a voyage from the [[River Tyne]] in [[England]] to [[Aden]] with a cargo of military stores — in the Mozambique Channel south of Beira on 28 June 1942;<ref name=combinedfleetI10/> ''Queen Victoria'' sank at {{coord|21|15|S|040|30|E|name=MV ''Queen Victoria''}}, with no survivors.<ref name=combinedfleetI10/> Still in the Mozambique Channel south of Beira on 30 June, she torpedoed the American 6,737-gross register ton armed steamer {{SS|Express|1940|6}}, which was on a voyage from Bombay to Cape Town with a cargo of [[manganese ore]], [[jute]], and [[leather]].<ref name=combinedfleetI10/> Two torpedoes hit ''Express'' on her starboard side and she sank by the [[stern]] at {{coord|23|30|S|037|30|E|name=SS ''Express''}}.<ref name=combinedfleetI10/> Eleven members of ''Express''′s crew and two personnel of her [[United States Navy Armed Guard]] drowned after abandoning ship when their boat was swamped in heavy seas.<ref name=combinedfleetI10/>

''I-10''′s success against Allied shipping in the Indian Ocean continued in July. At 16:15 on 6 July 1942, she torpedoed and sank the Greek 4,504-gross register ton merchant ship ''Nymphe'' at {{coord|15|48|S|040|42|E|name=''Nymphe''}}.<ref name=combinedfleetI10/> At 07:48 on 8 July, she torpedoed the British 5,498-gross register ton armed steamer {{SS|Hartismere}} — which was making a voyage from [[Philadelphia]], [[Pennsylvania]], to [[Alexandria]], [[Egypt]], via [[Lourenço Marques]], Portuguese East Africa, carrying 8,000 tons of general cargo — in the Mozambique Channel.<ref name=combinedfleetI10/> One torpedo hit ''Hartismere'' in the vicinity of her No. 1 [[Hold (ship)|hold]], triggering a violent explosion which started a fire and prompted her crew to abandon ship.<ref name=combinedfleetI10/> ''I-10'' surfaced and sank ''Hartismere'' with gunfire at {{coord|18|00|S|041|22|E}}, and ''Hartismere''′s crew and gunners made it to shore in her lifeboats at [[Caldera Point]] on the coast of Portuguese East Africa.<ref name=combinedfleetI10/>

''I-10''′s final victim of the Indian Ocean operation was the 4,427-ton Dutch armed merchant ship ''Alchiba'', which was on a voyage from Durban, South Africa, to [[London]] via Aden with a cargo of 4,000 tons of ammunition.<ref name=combinedfleetI10/> ''I-10'' torpedoed ''Alchiba'' at 17:55 on 8 July, hitting her in her [[engine room]] on the [[Port and starboard|port]] side.<ref name=combinedfleetI10/> The torpedo hit killed five [[Fireman (steam engine)|firemen]], destroyed two lifeboats, and knocked out all of ''Alchiba''′s lights.<ref name=combinedfleetI10/> Her surviving crew abandoned ship, after which ''I-10'' surfaced and fired nine {{convert|140|mm|in|1|adj=on|sp=us}} rounds at ''Alchiba''.<ref name=combinedfleetI10/> ''Alchiba'' broke in two and sank at {{coord|18|30|S|041|40|E|name=''Alchiba''}}.<ref name=combinedfleetI10/> Some of her survivors mistakenly claimed that two submarines had attacked her.<ref name=combinedfleetI10/> ''I-10'' returned to Penang on 30 July 1942.<ref name=combinedfleetI10/>

====August–October 1942====

''I-10'' departed Penang on 1 August 1942 bound for Yokosuka, which she reached on 12 August.<ref name=combinedfleetI10/> She remained in Japan until 21 October 1942, when she departed Yokosuka heading for [[Chuuk Atoll|Truk Atoll]]. She arrived at Truk on 27 October 1942.<ref name=combinedfleetI10/>

====Guadalcanal campaign====

The [[Guadalcanal campaign]] had begun with [[United States Marine Corps]] landings on [[Guadalcanal]] in the southeastern [[Solomon Islands (archipelago)|Solomon Islands]] on 7 August 1942.<ref name=combinedfleetI10/> While ''I-10'' was at Truk, she was reassigned to the "C" Patrol Unit on 31 October 1942.<ref name=combinedfleetI10/> On 24 November 1942 she got underway from Truk to patrol off [[Makira|San Cristobal]] in support of a midget submarine attack against Allied shipping in [[Lungga Roads]] off the north coast of Guadalcanal.<ref name=combinedfleetI10/><ref name=ijnsubsiteI10>[http://www.ijnsubsite.info/I-Sub%20Details/I-10.htm I-10 ijnsubsite.com 10 July 2018 Accessed 20 February  2022]</ref> She returned to Truk on 18 December 1942.<ref name=combinedfleetI10/>

====Third war patrol====

With a Yokosuka E14Y1 (Allied reporting name "Glen") floatplane aboard, ''I-10'' departed Truk on 5 January 1943, ordered to attack Allied shipping south of the Solomon Islands and conduct a reconnaissance of [[Nouméa]] on [[Grande Terre (New Caledonia)|Grande Terre]] in [[New Caledonia]], of [[New Zealand]] waters, and of the [[Torres Strait]].<ref name=combinedfleetI10/> She passed east of the Solomons on 10 January.<ref name=combinedfleetI10/> She sighted what she identified as an aircraft carrier escorted by two [[destroyer]]s on 16 January {{convert|80|nmi}} south-southeast of Nouméa and attempted a pursuit and attack, but she failed to achieve a good attack position and all of her torpedoes missed.<ref name=combinedfleetI10/> At 00:15 on 20 January 1943 she sighted what she identified as an unescorted [[Transport (ship)|transport]] south of Nouméa,<ref name=combinedfleetI10/> and at 00:20 on 23 January she sighted two destroyers east of Nouméa.<ref name=combinedfleetI10/> After dark on 24 January, she launched her floatplane for a reconnaissance flight over the Nouméa area — at a time when [[United States Secretary of the Navy]] [[Frank Knox]] and the [[Commander, U.S. Pacific Fleet|Commander-in-Chief of the United States Pacific Fleet]], [[Admiral (United States)|Chester W. Nimitz]], were in Nouméa for a Commander, [[South Pacific Area]] conference<ref name=combinedfleetI10/> —  and at 01:00 on 25 January its crew reported seeing several [[battleship]]s, [[cruiser]]s, destroyers, and transports in the harbor.<ref name=combinedfleetI10/>

On 30 January 1943, ''I-10'' was in the [[Coral Sea]] {{convert|115|nmi|0}} south of the [[Amédée Lighthouse]] on [[Amédée Island]] in New Caledonia when she hit the American 7,176-[[gross register ton]] [[Liberty ship]] {{SS|Samuel Gompers}} with a single torpedo in the stern at 04:49.<ref name=combinedfleetI10/> ''Samuel Gompers'', which was on a voyage from Nouméa to [[Newcastle, New South Wales|Newcastle]], [[New South Wales]], [[Australia]], suffered an explosion and sank at 04:54 at {{coord|24|28|S|166|20|E|name=SS m''Samuel Gompers''}}.<ref name=combinedfleetI10/> At about 14:00 on 9 February 1943, ''I-10'' fired torpedoes at what she identified as an unescorted transport, but the torpedoes passed under the ship without exploding.<ref name=combinedfleetI10/> At 05:42 on 10 February, she attacked another transport in the area, but failed to gain a good firing position and all her torpedoes missed.<ref name=combinedfleetI10/>

''I-10'' arrived off [[Auckland]], New Zealand, on 14 February 1943 and off [[Wellington]], New Zealand, on 16 February.<ref name=combinedfleetI10/> On 22 February, Allied [[signals intelligence]] intercepted several of ''I-10''′s transmissions and, based on them, estimated that ''I-10'' was about to pass through the [[Cook Strait]], not realizing that she had already transited the strait over a week earlier.<ref name=combinedfleetI10/> A [[Royal New Zealand Air Force]] search for ''I-10'' in the Cook Strait area found nothing.<ref name=combinedfleetI10/>

''I-10'' attacked a transport at 10:50 on 27 February 1943, but her torpedoes missed.<ref name=combinedfleetI10/> On 1 March 1943, however, she succeeded in torpedoing the American 7,141-gross register ton [[Tanker (ship)|tanker]] {{SS|Gulfwave}} in the [[New Hebrides]] at {{coord|20|30|S|174|45|E}}.<ref name=combinedfleetI10/> ''Gulfwave''′s crew and [[United States Navy Armed Guard]] detachment suffered no casualties, and the tanker made port at Suva in the Fiji Islands under her own power.<ref name=combinedfleetI10/><ref name="A WWII history 001">[http://asisbiz.com/Il2/US-Navy-History-WWII-1943.html], A WWII history</ref><ref name="A WWII history 002">[https://books.google.com/books?id=1EV4r9PlB8IC&dq=%2B%22gulfwave%22+%2B%22Tanker%22&pg=PA149], A WWII history</ref> After reconnoitering the Torres Strait on 5 March,<ref name=combinedfleetI10/> ''I-10'' headed back to Truk, which she reached on 10 March 1943.<ref name=combinedfleetI10/>

====March–June 1943====

''I-10'' got underway from Truk on 15 March 1943 and set course for [[Sasebo]], Japan, where she arrived on 21 March to undergo repairs.<ref name=combinedfleetI10/> With them complete, she departed Sasebo on 17 May 1943 and made for the [[Seto Inland Sea]] for workups and where from 17 to 19 May she engaged in refueling exercises in the Iyo-nada with the submarine {{ship|Japanese submarine|I-8||2}},<ref name=combinedfleetI10/> which had been selected to carry out a [[Yanagi missions|''Yanagi'' mission]], a round-trip voyage between Japan and [[Nazi Germany|German]]-[[occupied France]]<ref name=combinedfleetI8>{{cite web |url= http://www.combinedfleet.com/I-8.htm |title=IJN Submarine I-8: Tabular Record of Movement |first1=Bob |last1=Hackett |first2=Sander |last2=Kingsepp |work=combinedfleet.com |date=July 1, 2016|access-date=20 December 2021}}</ref> ''I-10'' arrived at Kure on 26 May 1943.<ref name=combinedfleetI10/>

On 1 June 1943, ''I-10'' departed Kure in company with ''I-8'' and the submarine tender {{ship|Japanese tender|Hie Maru||2}}.<ref name=combinedfleetI10/> The three vessels proceeded to [[Saeki Gulf]], then departed Saeki Gulf on 2 June and made for Penang, where ''I-10'' arrived on 12 June 1943<ref name=combinedfleetI10/> and was made [[flagship]] of Submarine Squadron 8.<ref name=combinedfleetI10/>

====Fourth war patrol====

On 27 June 1943, ''I-10'' departed Penang with the commander of Submarine Squadron 8, Rear Admiral [[Noboru Ishizaki]], aboard to begin her fourth war patrol in company with ''I-8'', which was beginning the next leg of her ''Yanagi''-mission voyage to France.<ref name=combinedfleetI10/><ref name=combinedfleetI8/> ''I-10'' refueled ''I-8'' at {{coord|04|53|S|087|20|E}} on 1 July and again at {{coord|22|25|S|076|15|E}} on 6 July 1943 before the two submarines separated, ''I-8'' proceeding on her voyage to France<ref name=combinedfleetI10/><ref name=combinedfleetI8/> and ''I-10'' beginning anti-shipping operations in the Indian Ocean. In the [[Gulf of Aden]], ''I-10'' hit the 7,634-gross register ton Norwegian tanker ''Alcides'' with two torpedoes on 22 July 1943.<ref name=combinedfleetI10/> ''Alcides'', which was on a voyage from [[Abadan, Iran|Abadan]], [[Iran]], to [[Fremantle]], Australia, sank at {{coord|03|S|068|E|name=''Alcides''}}.<ref name=combinedfleetI10/> ''I-10'' took ''Alcides''′s [[Sea captain|master]], radio officer, and [[second mate]] aboard, and they remained prisoners of war in Japan until freed by American forces on 29 August 1945.<ref name=combinedfleetI10/> ''I-10'' returned to Penang on {{nowrap|4 August 1943}}.<ref name=combinedfleetI10/>

====Fifth war patrol====

With a five-man film crew embarked to capture footage for the [[propaganda]] film ''Gochin!'' ("''Sunk!''") and a Yokosuka E14Y1 (Allied reporting name "Glen") floatplane aboard, ''I-10'' departed Penang at 16:00 on 2 September 1943 and headed back into the Indian Ocean to begin her fifth war patrol,<ref name=combinedfleetI10/> assigned a patrol area in the [[Gulf of Aden]]. On 14 September, she torpedoed and sank the 6,361-gross register ton Norwegian tanker ''Bramora'' — which was carrying oil from [[Bandar Abbas]], Iran, to [[Melbourne]], Australia — southwest of the [[Chagos Archipelago]] at {{coord|06|00|N|067|00|E|name=''Bramora''}}.<ref name=combinedfleetI10/> At dawn on 20 September 1943, her floatplane flew a reconnaissance mission over [[Perim Island]] in the [[Bab-el-Mandeb]] to investigate a report that the Allies had constructed an airfield there, but its crew found no airfield on the island.<ref name=combinedfleetI10/>

''I-10'' returned to the Gulf of Aden, where at about 02:00 on 24 September 1943 she sighted the American 7,634-gross register ton Liberty ship {{SS|Elias Howe}} {{convert|75|nmi}} southeast of [[Aden]].<ref name=combinedfleetI10/> She fired two torpedoes at 03:12, one of which struck ''Elias Howe'', killing two men in her [[engine room]] and starting a large fire.<ref name=combinedfleetI10/> ''Elias Howe'' transmitted an [[SOS]].<ref name=combinedfleetI10/> ''I-10'' surfaced and hit ''Elias Howe'' with another torpedo, and 15 minutes after the second hit explosives aboard ''Elias Howe'' detonated.<ref name=combinedfleetI10/> ''Elias Howe'' sank by the stern at {{coord|11|40|N|044|35|E|name=SS ''Elias Howe''}}.<ref name=combinedfleetI10/> The [[Royal Navy]] [[Naval trawler|armed trawler]] {{HMS|Aiglon}} and a [[seaplane]] rescued ''Elias Howe''′s survivors.<ref name=combinedfleetI10/>

At about 16:30 on 1 October 1943, ''I-10'' sighted an Allied [[convoy]] in the Gulf of Aden heading west at {{convert|10|kn}} and set out in pursuit.<ref name=combinedfleetI10/> She fired three torpedoes at the 4,836-gross register ton Norwegian armed merchant ship {{SS|Storviken}}, which was carrying a cargo of [[coal]] from [[Mombasa]] in [[Kenya Colony|British East Africa]] to Aden.<ref name=combinedfleetI10/> Two torpedoes hit ''Storviken'' on her starboard side, and she sank by the stern at {{coord|11|4|N|048|07|E|name=''Storviken''}}.<ref name=combinedfleetI10/> ''I-10'' took two members of her crew prisoner.<ref name=combinedfleetI10/>

At around 16:10 on 4 October 1943, ''I-10'' detected the sound of multiple [[propeller]]s while submerged in the Gulf of Aden, and soon sighted Convoy AP-47, consisting nine merchant ships bound from Aden to Abadan escorted by two destroyers.<ref name=combinedfleetI10/> ''I-10'' pursued the convoy, surfacing after sunset.<ref name=combinedfleetI10/> When {{convert|140|nmi|0}} northwest of [[Cape Guardafui]], the northernmost tip of [[British Somaliland]], at 05;10 on 5 October, she fired three torpedoes at overlapping targets at a range of {{convert|6,340|yd|sigfig=3}}, then dived to {{convert|390|ft|0}}.<ref name=combinedfleetI10/> One torpedo struck the 9,057-gross register ton Norwegian armed tanker {{SS|Anna Knudsen}} on her starboard [[Bow (ship)|bow]] at {{coord|14|20|N|050|47|E}}. As major flooding progressed, her master ordered her crew to abandon ship, but the crew returned to ''Anna Knudsen'' when the flooding abated.<ref name=combinedfleetI10/> ''I-10''′s crew, meanwhile, reported hearing three loud explosions followed by breaking-up noises indicating the sinking of one or more ships, and claimed three merchant ships sunk.<ref name=combinedfleetI10/> ''I-10'' suffered minor damage to her engine room during a brief depth-charging by the convoy′s escorts.<ref name=combinedfleetI10/>

In the Indian Ocean near [[Addu Atoll]] on 24 October 1943 at 11:25, ''I-10'' fired two torpedoes at the British 4,533-gross register ton armed motor vessel {{MV|Congella}}, which was on a voyage from [[Calcutta]] in [[British India]] to Durban, South Africa, carrying 8,700 tons of general cargo.<ref name=combinedfleetI10/> Both torpedoes missed, so ''I-10'' surfaced and opened gunfire, starting a fire aboard ''Congella''.<ref name=combinedfleetI10/> ''Congella''′s crew abandoned ship, and she sank at {{coord|01|02|N|071|14|E|name=MV ''Congella''}}.<ref name=combinedfleetI10/> ''I-10'' took her radio operator prisoner.<ref name=combinedfleetI10/> The British [[whaling ship]] ''Okapi'' and two [[Royal Air Force]] [[Consolidated PBY Catalina|Catalina]] [[flying boat]]s rescued her other 37 survivors.<ref name=combinedfleetI10/> Three gunners and 25 crew died in her sinking.<ref name=combinedfleetI10/> ''I-10'' concluded her patrol with her return to Penang on 30 October 1943.<ref name=combinedfleetI10/>

====November 1943–February 1944====

''I-10'' departed Penang on 5 November 1943, called at Singapore from 7 November to 7 December 1943, and then proceeded to Sasebo, which she reached on 16 December 1943.<ref name=combinedfleetI10/> She underwent repairs and an overhaul at Sasebo, during which she was attached directly to 6th Fleet headquarters on 1 January 1944.<ref name=combinedfleetI10/> When her repairs were complete, ''I-10'' departed Sasebo on 3 February 1944 bound for Truk.<ref name=combinedfleetI10/> On 9 February 1944, [[Fleet Radio Unit, Melbourne|Fleet Radio Unit, Melbourne (FRUMEL)]], an Allied signals intelligence unit in Melbourne, Australia, decrypted a Japanese message reporting that ''I-10'' would arrive at Truk via the North Channel on 10 February 1944, but she arrived safely at Truk on 10 February despite the Allied knowledge of her schedule.<ref name=combinedfleetI10/>

====Operation Hailstone====
During ''I-10''′s stay at Truk, U.S. Navy [[Task Force 58]] conducted [[Operation Hailstone]], a major attack on Truk by [[Aircraft carrier|carrier]] aircraft supported by anti-shipping sweeps around the [[atoll]] by surface warships, on 17 and 18 February 1944.<ref name=combinedfleetI10/> ''I-10'' suffered three killed and two wounded and sustained minor damage during the first day of the raid, but she and the submarines {{ship|Japanese submarine|Ro-36||2}} and {{ship|Japanese submarine|Ro-42||2}} put to sea on 17 February in an attempt to intercept the attacking ships.<ref name=combinedfleetI10/><ref>{{cite web |url= http://www.combinedfleet.com/RO-36.htm |title=IJN Submarine RO-36: Tabular Record of Movement |first1=Bob |last1=Hackett |first2=Sander |last2=Kingsepp |work=combinedfleet.com |year=2017|access-date=20 September 2020}}</ref> ''I-10'' searched for them east of [[Tonowas|Dublon]] (known to the Japanese as Natsushima)<ref name=combinedfleetI10/> without success and returned to Truk.

====Sixth war patrol====

''I-10'' departed Truk for her sixth war patrol on 25 February 1944, intending to operate off the U.S. West Coast.<ref name=combinedfleetI10/> On 4 March 1944, however, she suffered damage in a depth-charge attack in the Pacific Ocean east of [[Mili Atoll]] and was forced to abort her patrol.<ref name=combinedfleetI10/> She arrived at Yokosuka on 20 March 1944 for repairs.<ref name=combinedfleetI10/> While she was under repair, workers probably installed an E27 Type 3 [[radar detector]] and a Type 3 [[sonar]] aboard her.<ref name=combinedfleetI10/>

====Seventh war patrol====

With her repairs complete, ''I-10'' left Yokosuka on 4 May 1944 with a Yokosuka E14Y1 (Allied reporting name "Glen") floatplane embarked to begin her seventh war patrol, assigned a patrol area in the Pacific Ocean east of the [[Marshall Islands]].<ref name=combinedfleetI10/> After dark on 12 June 1944, her floatplane reconnoitered the American fleet anchorage at [[Majuro Atoll]], but an American expeditionary force had departed Majuro six days earlier, and the plane's crew found no ships there.<ref name=combinedfleetI10/><ref name=morison>Morison, Samuel Eliot, "History of United States Naval Operations in World War II: Volume Eight - New Guinea and the Marianas March 12944 - August 1944," Little, Brown and Company, Boston, 1953, 1989, Library of Congress card number 53-7298, page 229.</ref> Upon returning to ''I-10'', the floatplane [[capsize]]d and was lost, although ''I-10'' recovered its crew.<ref name=combinedfleetI10/><ref name=morison/>

On 13 June 1944, the commander-in-chief of the Combined Fleet, Admiral [[Soemu Toyoda]], activated Operation A-Go for the defense of the [[Mariana Islands]] and ordered the commander-in-chief of the 6th Fleet, Vice Admiral [[Takeo Takagi]] on [[Saipan]], to redeploy all 6th Fleet submarines to the Marianas.<ref name=combinedfleetI10/> Takagi, in turn, ordered all 18 available submarines, including {{nowrap|''I-10''}}, to deploy east of the Marianas.<ref name=combinedfleetI10/> The [[Mariana and Palau Islands campaign|Marianas campaign]] began on 15 June 1944 with U.S. landings on Saipan, beginning the [[Battle of Saipan]] and disrupting communications with Takagi, so the commander of Submarine Squadron 7, Rear Admiral [[Noboru Owada]], took temporary command of the 6th Fleet and ordered all but six of the submarines to withdraw from the Marianas.<ref name=combinedfleetI10/> {{nowrap|''I-10''}} was among the six ordered to remain.<ref name=combinedfleetI10/>

On 24 June 1944, the Combined Fleet ordered Owada to evacuate Takagi and his staff from their headquarters on the eastern coast of Saipan.<ref name=combinedfleetI10/> {{nowrap|''I-10''}} was operating east of Saipan at the time, so Owada ordered her to conduct the evacuation.<ref name=combinedfleetI10/> At 12:00 [[Japan Standard Time]] on 28 June 1944, {{nowrap|''I-10''}} reported that she was {{convert|40|nmi}} northeast of Saipan and had not found it possible to break through the cordon of American ships off Saipan to reach Takagi and his staff.<ref name=combinedfleetI10/> The Japanese never heard from her again, and on 2 July 1944 declared her to be presumed lost off Saipan with all 103 hands.<ref name=combinedfleetI10/>

====Loss====

In fact, ''I-10'' had not yet been lost on 2 July, but she did not survive much longer. At 17:02 on 4 July 1944, U.S. Navy [[Task Group]] 50.17, with six tankers and the [[escort carrier]] {{USS|Breton|CVE-23}}, was refueling at sea {{convert|110|nmi}} northeast of Saipan when the [[destroyer escort]] {{USS|Riddle |DE-185}} gained sound contact on a submerged submarine bearing 250 degrees at a range of {{convert|1,900|yd|m|sigfig=3}}.<ref name=combinedfleetI10/> While the task group made an emergency turn to port, ''Riddle'' quickly dropped five depth charges.<ref name=combinedfleetI10/> ''Riddle'' then began an approach for another attack but the submarine turned into the [[Wake (physics)|wakes]] of the ships of the retiring task group, and ''Riddle'' lost contact in the turbulence.<ref name=combinedfleetI10/>

After 18 minutes, ''Riddle'' regained contact at a range of {{convert|1,250|yd|m|sigfig=3}}.<ref name=combinedfleetI10/> She fired three patterns of [[Hedgehog (weapon)|Hedgehog]] projectiles, but the submarine dived deeper and maneuvered aggressively, avoiding the projectiles.<ref name=combinedfleetI10/> At 18:12, ''Riddle'' made another attack with a full pattern of depth charges set to explode deep, but without result.<ref name=combinedfleetI10/>

''Riddle'' passed the estimated range, bearing, and course of the submarine to the destroyer {{USS|David W. Taylor|DD-551}}, which established contact on the submarine at 18:22.<ref name=combinedfleetI10/> ''David W. Taylor'' dropped 11 depth charges set to explode at medium depth.<ref name=combinedfleetI10/> ''Riddle'' was about to begin another attack when a heavy underwater explosion occurred directly ahead of her at 18:28.<ref name=combinedfleetI10/> Neither ship obtained any more contacts, and by sunset oil and debris had reached the surface at {{coord|15|26|N|147|48|E|name=''I-10''}}.<ref name=combinedfleetI10/> It marked the demise of ''I-10''.<ref>Boyd & Yoshida, p. 209</ref> On 5 July 1944, an oil slick extended {{convert|9|nmi}} downwind from the point of attack.<ref name=combinedfleetI10/>

The Japanese removed ''I-10'' from the [[Navy list]] on 10 October 1944.<ref name=combinedfleetI10/>

==Notes==
{{Reflist|30em}}

==References==
*{{cite book|last=Bagnasco |first=Erminio |title=Submarines of World War Two |year=1977 |publisher=Naval Institute Press |location=Annapolis, Maryland |isbn=0-87021-962-6}}
*{{cite book|last1=Boyd|first1=Carl|last2=Yoshida|first2=Akikiko|title=The Japanese Submarine Force and World War II|date=2002|publisher=Naval Institute Press|location=Annapolis, Maryland|isbn=1-55750-015-0|name-list-style=amp}}
*{{cite book|last1=Carpenter|first1=Dorr B.|last2=Polmar|first2=Norman|title=Submarines of the Imperial Japanese Navy 1904–1945|year=1986|publisher=Conway Maritime Press|location=London|isbn=0-85177-396-6|name-list-style=amp}}
*{{cite book|title=Conway's All the World's Fighting Ships 1922–1946|editor1-last=Chesneau|editor1-first=Roger|publisher=Conway Maritime Press|location=Greenwich, UK|year=1980|isbn=0-85177-146-7}}
*{{cite web|url=http://www.combinedfleet.com/I-10.htm|title=IJN Submarine I-10: Tabular Record of Movement|last1=Hackett|first1=Bob|last2=Kingsepp|first2=Sander|year=2012|work=SENSUIKAN! Stories and Battle Histories of the IJN's Submarines|publisher=Combinedfleet.com|access-date=18 August 2015}}
*{{cite book|last=Edwards |first=Bernard |title=Blood and Bushido: Japanese Atrocities at Sea 1941–1945 |year=1997 |publisher=Brick Tower P0ress |location=New York |isbn=1-883283-18-3}}
*{{cite book|last=Hashimoto|first=Mochitsura|others=Colegrave, E.H.M. (translator)|title=Sunk: The Story of the Japanese Submarine Fleet 1942 – 1945|publisher=Cassell and Company|location=London|year=1954|id=ASIN B000QSM3L0}}
*{{cite book|last=Stille|first=Mark|title=Imperial Japanese Navy Submarines 1941-45| series =New Vanguard|volume=135|year=2007|publisher=Osprey Publishing|location=Botley, Oxford, UK|isbn=978-1-84603-090-1}}
{{Type A submarine}}
{{December 1941 shipwrecks}}
{{July 1944 shipwrecks}}

{{DEFAULTSORT:I-010}}
[[Category:Type A1 submarines]]
[[Category:1939 ships]]
[[Category:World War II submarines of Japan]]
[[Category:Friendly fire incidents of World War II]]
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[[Category:Maritime incidents in December 1941]]
[[Category:Maritime incidents in July 1944]]
[[Category:World War II shipwrecks in the Pacific Ocean]]
[[Category:Ships built by Kawasaki Heavy Industries]]
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[[Category:Warships lost in combat with all hands]]
[[Category:Submarines lost with all hands]]