I-26 departed Yokosuka at 15:00 on 19 November 1941 and set course for the Aleutians with orders to reconnoiter American naval bases there and report on the United States Navy presence in the area to the commander-in-chief of the Combined Fleet, Admiral Isoroku Yamamoto, by 5 December 1941, then proceed to a patrol area in the Pacific Ocean halfway between San Francisco, California, and Hawaii to observe and report any American reinforcements headed toward Hawaii from the United States West Coast.

[2][3][4][8][9] The American ocean liner SS Lurline picked up Cynthia Olson′s SOS from a considerable distance away[7] and on 8 December the Japanese submarine I-19 came across her lifeboats and provided her survivors — 33 crewmen and two U.S. Army passengers — with food, but after that they were never seen or heard from again.

[3] I-26 arrived in her assigned patrol area in the Strait of Juan de Fuca off Cape Flattery, Washington, near Seattle on 20 December 1941 and sighted several merchant ships, but could not make any attacks due to heavy seas and poor visibility.

[3] After refueling they took off again, made the seven-hour flight to Honolulu, dropped their bombs early on 5 March without achieving anything of importance, and returned to the Marshall Islands safely.

5 at Yokosuka, 16 United States Army Air Forces B-25 Mitchell medium bombers launched from the aircraft carrier USS Hornet (CV-8) struck targets in Japan on 18 April 1942 in the Doolittle Raid.

[3] Some of I-26′s crew aboard her and ashore witnessed part of the raid, and one B-25 bombed and damaged the light aircraft carrier Ryūhō, which was undergoing conversion from the submarine tender Taigei in the adjacent Drydock No.

[3] On the afternoon of 7 June 1942, she was 35 nautical miles (65 km; 40 mi) southwest of Cape Flattery, Washington, when she fired a Type 89 torpedo at the 3,286-gross register ton cargo ship SS Coast Trader — which had departed Port Angeles, Washington, that day bound for San Francisco, California, with a cargo of 1,250 tons of newsprint — as she left the Strait of Juan de Fuca.

[2][3][13] One crewman died of exposure before the remainder were rescued over the following two days by the fishing schooner Virginia I and the Royal Canadian Navy corvette HMCS Edmundston.

"[3][13] At 22:17 on 20 June 1942, I-26 surfaced either 2 or 5 nautical miles (3.7 or 9.3 km; 2.3 or 5.8 mi) (according to different sources) off the west coast of Vancouver Island in British Columbia, Canada, and shelled the Hesquiat radio-direction-finding (RDF) installation at Estevan Point with her 140-millimeter (5.5 in) deck gun.

[2][3] Despite its lack of success, the shelling — which some local eyewitnesses mistakenly attributed to two cruisers[3] — had a disproportionate effect on coastal shipping, as all lighthouses along the west coast of North America subsequently were extinguished to prevent their use for navigation by enemy vessels.

[3] Just as she began to head back for her patrol area 140 nautical miles (260 km; 160 mi) east of San Cristobal in the southeastern Solomon Islands,[3] one of her lookouts using her night binoculars sighted a ship resembling a large tanker at a range of 25,200 yards (23,000 m).

[3] One torpedo suffered a steering malfunction and broached and four others missed, but one hit Saratoga on her starboard side aft at 07:48 at 10°34′S 164°18′E / 10.567°S 164.300°E / -10.567; 164.300, flooding one of her fire rooms.

At 09:30 on 13 September 1942, a Yokohama Air Group Kawanishi H8K flying boat reported an Allied task force 345 nautical miles (639 km; 397 mi) south-southeast of Tulagi in the Solomon Islands, and I-26 along with I-9, I-15, I-17, I-21, and the submarines I-24, I-31, and I-33 received orders to form a patrol line in the area.

[2] On 5 October 1942, I-26 departed Truk in company with I-15 and I-19, ordered to recharge the batteries of midget submarines from the seaplane carrier Chiyoda off Cape Esperance on the northwestern tip of Guadalcanal, then proceed to the Indispensable Reefs south of San Cristobal to relieve I-15 on duty refueling floatplanes there.

[3] She surfaced at 23:41 and transmitted a report of her sighting to Truk, but a delay in decoding it there prevented it from reaching Rear Admiral Aritomo Gotō — steaming toward Guadalcanal to bombard Henderson Field — in time to warn him of approaching enemy ships, and his force was surprised and defeated by a task force under Rear Admiral Norman Scott in the Battle of Cape Esperance that night.

[3] She concluded her patrol with her arrival at Truk on either 29[3] or 30[2] November 1942, according to different sources, where her claim for sinking Juneau was not confirmed because the Japanese lacked information on Juneau′s identity.

She arrived off Cape Esperance at the northwest tip of Guadalcanal on 28 January 1943 and pointed her stern directly at the coast to aid the container′s pilot in reaching shore.

[3] On 2 February 1943 I-26 was among submarines ordered to intercept a U.S. Navy aircraft carrier force reported to be 100 nautical miles (190 km; 120 mi) southeast of Rennell Island.

[3] On 8 February 1943, Japanese aircraft reported U.S. Navy forces 150 nautical miles (280 km; 170 mi) southeast of Rennell Island, and I-26 again was among the submarines ordered to intercept them.

[3] After 19:00 on 24 April 1943, I-26 fired three torpedoes at the Australian 2,125-gross register ton armed cargo ship SS Kowarra in the Coral Sea 35 nautical miles (65 km; 40 mi) northeast of Sandy Cape at the northern tip of Fraser Island off the coast of Queensland, Australia.

[2][3] I-26 began her sixth war patrol on 14 June 1943 with her departure from Truk to raid shipping in the Fiji area and divert Allied attention from Japanese activities elsewhere.

[2][3] As she approached an Allied convoy 180 nautical miles (330 km; 210 mi) southwest of Suva, Fiji, on 25 June 1943, a Lockheed Hudson patrol bomber of the Royal New Zealand Air Force′s No.

[3] As Albert Gallatin began to sink, a Royal Air Force Bristol Blenheim aircraft arrived on the scene and dropped four bombs on I-26, inflicting minor damage on her.

On 16 March 1944, she torpedoed the American 8,298-gross register ton armed tanker SS H. D. Collier — a ship operated by Standard Oil of California and making a voyage from Iran to Bombay with a cargo of 103,000 barrels of kerosene — in the Arabian Sea 330 nautical miles (610 km; 380 mi) south-southwest of Karachi.

[27] I-26 then surfaced less than 1 nautical mile (1.9 km; 1.2 mi) from the lifeboats and 500 yards (460 m) off Richard Hovey′s port bow and opened fire on the ship with her 140-millimeter (5.5 in) deck gun, scoring hits immediately.

[3][27] She rammed one of the boats, capsizing it and riddling its drinking water tanks, causing them to empty into the sea, before moving carefully around the boats, rafts, and debris and firing on any sign of a survivor while crewmen on her deck laughed; survivors noted that among men on I-26′s bridge were a Japanese man carefully filming the attack and a man wearing a turban, who they assumed was a member of the Indian National Army.

The 25 men aboard one boat were rescued on the first of April 200 nautical miles (370 km; 230 mi) east of the site of the sinking by the British Liberty ship SS Samcalia and were landed at Karachi on the fourth.

[3] I-26 departed Kure on 27 June 1944 bound for Saipan with an Unpoto supply container — a 70-foot (21 m) sled that could carry up to 15 tons of cargo — secured on her deck with a 75-millimeter gun inside it.

[2][3] I-26, I-45, and the submarines I-53, I-54, and I-56 were designated Group A under the personal leadership of the commander-in-chief of the 6th Fleet, Vice Admiral Shigeyoshi Miwa, and ordered to intercept U.S. Navy Task Force 38.

[3] I-26 was the Imperial Japanese Navy′s third-highest-scoring submarine in terms of tonnage sunk during World War II, sinking more than 51,500 tons of enemy shipping.