[5] During March 1945, after the United States Army Air Forces Twentieth Air Force conducted a major fire-bombing raid on Tokyo on the night of 9-10 March 1945, the 6th Fleet proposed to the Imperial Japanese Navy General Staff a retaliatory raid on San Francisco, California, by Aichi M6A1 Seiran floatplanes launched by the submarines of Submarine Division 1, but by April 1945 the General Staff's vice chief, Vice Admiral Jisaburō Ozawa, had rejected the proposal.

[5] They departed Chinkai on 29 May to return to Japan, stopping at Toyama Bay on the coast of Honshu on 1 June 1945 because of dense fog.

[6] I-13, I-400, and I-401 soon rendezvoused with I-14 in Nanao Bay, and the submarines were joined by six Aichi M6A1 Seiran ("Clear Sky Storm") aircraft of the Kure-based 631st Naval Air Group, which flew in on 4 June after a stop at Fukuyama, Japan.

[7] On 6 June 1945, the submarines and aircraft began training for night air operations in preparation for a surprise Japanese air strike against the Panama Canal in which the submarines would launch ten M6A1 floatplanes which were to strike the Gatun Locks from the east with six torpedoes and four bombs, emptying Gatun Lake and blocking the canal to shipping for months.

[7] The submarines and aircraft completed their flight training on 19 June 1945, with all of the M6A1 floatplanes taking off from the waters of Nanao Bay that day.

[5] At 13:25 on 25 June 1945, the Combined Fleet issued orders for the attack on Ulithi, dubbed Operation Arashi ("Mountain Storm").

[5][7] The orders called for I-13 and I-14 to transport disassembled Nakajima C6N1 Saiun (Iridiscent Cloud"; Allied reporting name "Myrt") reconnaissance aircraft to Truk Atoll in the Caroline Islands in late July 1945.

[5][7] I-400 and I-401 then were to launch a combined total of six M6A1 floatplanes—which were to use the reconnaissance information to assist them in targeting Allied ships—on 17 August 1945 for a nighttime strike under a full moon against the Ulithi anchorage, each pilot receiving a hormone injection to improve his night vision and each plane armed with an 800-kilogram (1,764 lb) bomb.

[5][7] On 2 July 1945, I-14 departed Maizuru in company with I-13 and set course for Ōminato on the northern tip of Honshu, where plans called for them to load crated C6N aircraft and proceed to Truk.

[5] On the day of her departure, Fleet Radio Unit, Melbourne (FRUMEL), an Allied signals intelligence unit at Melbourne, Australia, decrypted a message which informed the Allies that I-14 would depart Ōminato at 15:00 that day bound for Truk and expected to be 165 nautical miles (306 km; 190 mi) bearing 106 degrees from Cape Shiriya at 03:00 on 19 July, at which point she planned to alter course to 110 degrees.

[5] At 03:30 Japan Standard Time (JST) on 3 August 1945, she detected propeller noises from multiple vessels 150 nautical miles (280 km; 170 mi) northeast of Truk, and shortly afterward she sighted a group of what she identified as U.S. Navy submarine chasers.

[5] At 21:00 on 18 August 1945, Submarine Division 1′s commander, Captain Ariizumi, at sea aboard I-401 to conduct the Ulithi attack, received orders from the 6th Fleet to cancel it, and later that day the 6th Fleet ordered I-14, I-400, and I-401 to jettison all aircraft, torpedoes, other munitions, and documents, hoist the designated black flag of surrender, and proceed on the surface first to Hong Kong and then to Japan.

[5] She was on the surface in the Pacific Ocean east of Honshu at 37°38′N 144°52′E / 37.633°N 144.867°E / 37.633; 144.867 flying the black surrender flag on 27 August 1945 when a plane from U.S. Navy Task Force 38 sighted her and reported her position.

[5] On 28 August 1945, the U.S. Navy destroyer escort USS Bangust (DE-739) rendezvoused with them 450 nautical miles (830 km; 520 mi) east of Nojimazaki and sent a prize crew of U.S. Navy personnel aboard I-14 to take command of her in exchange for forty I-14 personnel, who became prisoners-of-war aboard Bangust.

[5] I-14 departed Yokosuka on 1 November 1945 bound for Sasebo, Japan, in company with I-400 and I-401, also operated by U.S. Navy crews, and escorted by the submarine rescue vessel USS Greenlet (ASR-10).

[7] After loading Japanese motor launches onto their decks to serve as lifeboats,[7] I-14, I-400, and I-401 departed Sasebo on 11 December 1945 bound for Pearl Harbor, Hawaii, under escort by Greenlet and manned by U.S. Navy crews, with I-14 under the command of Commander John S. McCain Jr.[7] A few days after departure, the vessels weathered a powerful storm, during which I-14′s crew noted that her hangar, offset to starboard, threw her off balance in heavy seas and created rough riding for the men aboard her.

[7] Accordingly, the U.S. Navy submarine USS Bugara (SS-331) sank I-14 as a target in tests of the Mark 10 Mod 3 exploder off Pearl Harbor at 21°13′N 158°08′W / 21.217°N 158.133°W / 21.217; -158.133 (=I-14) on 28 May 1946.

[5][9] On 17 February 2009, the two submersibles conducted extensive surveys of the wrecks of I-14 and the Japanese submarine I-201, also lying in two pieces in the area[5] after the U.S. Navy sank her as a target in 1946.

[9] The search for the wrecks and video footage of them on the ocean bottom was featured in Hunt for the Samurai Subs, which premiered in the United States on the National Geographic Channel on 17 November 2009.