Submarine I-168

IJN I-168 was a Kaidai-type (KD6a) submarine originally designated I-68, built at Kure Naval Arsenal and commissioned on July 31, 1934. She was redesignated I-168 on May 20, 1942 as part of a general submarine renumbering. Armed with six torpedo tubes and a 100mm deck gun, she carried a crew of about 80 men.

At the Battle of Midway, I-168 played a dual role. First, on June 1, 1942, she conducted a pre-battle reconnaissance of Midway Atoll under Lieutenant Commander Yahachi Tanabe, reporting the atoll's defenses to Combined Fleet Headquarters. Then, after the devastating air battle of June 4-5 that destroyed four Japanese carriers, the damaged USS Yorktown (CV-5) was still afloat and under tow. On June 6, 1942, I-168 penetrated the destroyer screen at periscope depth. At 13:31, from 1,900 yards, she fired four torpedoes. One struck and sank the destroyer USS Hammann (DD-412), which was alongside Yorktown providing power. Two others hit Yorktown. Hammann sank in four minutes with heavy loss of life. Yorktown rolled over and sank the following morning — she was the only fleet carrier the US Navy lost at Midway, and USS Hammann was the only destroyer. I-168 evaded intense counter-attacks and escaped.

I-168 was sunk on July 27, 1943, by USS Scamp (SS-277) in the Bismarck Sea approximately 60 nautical miles off New Hanover Island, with the loss of all 97 crew members.