[5] She moved to Kure, Japan, in late May 1942 for work-ups, embarking an 11th Naval Air Arsenal Yokosuka E14Y1 (Allied reporting name "Glen") floatplane for aircraft launch and recovery exercises.

[5] She continued her floatplane launch and recovery exercises at Kwajalein, during which one member of her crew suffered injuries due to an aircraft catapult malfunction.

[5] While on the surface there at 23:01 Australian Eastern Time on 20 July 1942, she hit the Greek 5,482-gross register ton steamer SS George S. Livanos with one torpedo 15 nautical miles (28 km; 17 mi) off Jervis Bay, New South Wales, Australia.

[5] On 22 July 1942 at 05:45, I-11 was on the surface off the coast of New South Wales 25 nautical miles (46 km; 29 mi) east of the lighthouse at Twofold Bay when she fired three torpedoes at the American armed Liberty ship SS William Dawes, which was carrying a cargo of 82 jeeps, 72 half-ton pickup trucks, 60 one-ton trailers, and dozens of trucks, ambulances and halftracks.

[5] As I-11 continued to work her way to the southwest, her lookouts sighted what they reported as a convoy of eight transports escorted by two light cruisers and two destroyers at about 12:00 on 24 July 1942.

[5] At 04:06 on 27 July, she fired a single torpedo at the Australian 2,197-gross register ton merchant ship Coolana while 30 nautical miles (56 km; 35 mi) north of Cape Howe.

100 Squadron attacked I-11 when she was off Disaster Bay, 22 nautical miles (41 km; 25 mi) northeast of Gabo Island, and heading south at 7 knots (13 km/h; 8.1 mph).

[5] At 02:50 on 31 July, 15 nautical miles (28 km; 17 mi) southwest of the lighthouse at Cape Everard, she fired two torpedoes at overlapping targets and heard one explosion.

[5] On 1 August 1942, I-11 reached the southernmost boundary of her patrol area at the eastern entrance to the Bass Strait and began her return voyage.

[5] On 26 August 1942, the commander of the Advance Force ordered I-11 and the submarines I-15, I-17, I-19, I-26, I-33, I-174, and I-175 to deploy to the south and east of San Cristobal to interdict American supplies and reinforcements bound for Guadalcanal.

[6] While in the Coral Sea 146 nautical miles (270 km; 168 mi) southeast of Tulagi at 04:05 on 31 August 1942, I-11 attacked what she identified as a 15,000-ton transport escorted by a destroyer and claimed two torpedo hits.

[5] The task force's escorts began searching for I-11, and at 14:52 the destroyer USS Russell (DD-414) gained contact on her and dropped six 600-pound (272 kg) depth charges.

[5] Russell′s subsequent depth-charge attack resulted in a number of explosions close aboard that caused a minor leak at I-11′s stern through her propeller shaft gland, temporarily disabled her sound gear, and wrecked 80 per cent of her batteries.

She reached Kure on 23 September 1942, returned her floatplane — which had survived Russell′s depth-charging in flyable condition — to the 11th Naval Air Arsenal, and began repairs.

[5] With a Yokosuka E14Y (Allied reporting name "Glen") floatplane aboard, I-11 departed Truk on 19 January 1943 to begin her third war patrol,[5] resuming her participation in the Guadalcanal campaign.

[5] On 31 January 1943, I-11 received orders to proceed to the waters east of San Cristóbal[5] in support of ships of the 2nd and 3rd Fleets as they conducted the evacuation.

[5] At 10:00 on 7 February 1943, I-11 sighted a U.S. aircraft carrier steaming south and began an approach, but an inaccurate depth setting for I-11′s torpedoes prevented a successful attack.

Meanwhile, I-11 received orders on 7 February 1943 after her unsuccessful attempt to attack the aircraft carrier to use her floatplane to reconnoiter the harbor and nearby airfields at Nouméa on the coast of Grande Terre in New Caledonia.

[5] While 70 nautical miles (130 km; 81 mi) north of Gabo Island on 27 April 1943 she made an unsuccessful attack on Convoy OC-90 during its voyage from Melbourne, Victoria, to Newcastle, New South Wales.

[5] On 29 May 1943, she fired two torpedoes at the American Liberty ship SS Sheldon Jackson 150 nautical miles (280 km; 170 mi) northeast of Sydney, Australia, but both missed.

[5] I-11 departed Truk with a Yokosuka E14Y1 (Allied reporting name "Glen") floatplane embarked to commence her fifth war patrol on 1 July 1943.

[5] They passed astern of Australia, but at 18:45 one of them struck the Australian light cruiser HMAS Hobart on her port quarter at 15°07′S 163°43′E / 15.117°S 163.717°E / -15.117; 163.717, breaking her keel, blowing off two propellers, unseating "Y" turret, knocking out all power and steering control, and killing 13 crewmen and badly injuring seven others.

[5] After sunset on 25 July 1943, I-11′s floatplane made a reconnaissance flight over the Nouméa area, its crew reporting cruisers and smaller ships in the harbor there.

[9] Post-World War II Japanese research has suggested that a mine laid by the U.S. Navy minelayer USS Terror (CM-5) sank I-11.