I-13 was a Type AM submarine (巡潜甲型改二潜水艦 - "Cruiser submarine type A modified 2")  built for the Imperial Japanese Navy  in 1943. The i13 was a giant submarine, originally of the A2 type, but it's design was revised after construction started so that  it could carry a second aircraft.  there were 7 of this class planned, 2 were built and 5 were canceled.

 I-13 served between the years of 1943 to 1945.

Preceded by:  Type A2 submarine

I-13 Laid down at Kawasaki's Kobe Yard as Submarine No. 621, the first A Modified class submarine. The AM-class will carry two Aichi M6A1 Seiran (Mountain Haze) float torpedo-bombers, range 654 miles. In October 1943 prior to launching, the submarine was renumbered I-13.

i-13 came at the very end of the war, and with an ever changing war situation never got to perform the role for which it was designed. 

Her final record of movement:

16 July 1945: 

550 miles E of Yokosuka. At 0747, the radar-man in Lt (j.g.) William McLane's Grumman TBM-3E "Avenger" from VC-13 of Task Group 30.7's USS ANZIO (CVE-57) picks up a Japanese submarine running on the surface. McLane opens fire with his .50 cal. machine guns and 5-inch rockets. The submarine dives, but leaves a trail of oil on the surface. McLane drops Mk. 54 depth charges, then sonobuoys and a Mk. 24 "Fido" acoustic homing torpedo.

Later, two more Avengers from ANZIO's aircraft relieve McLane. They drop more sonobuoys and another "Fido" on the submerged submarine. Later, the aircraft guide LtCdr J. R. Grey's LAWRENCE C. TAYLOR (DE-415) to the heavy oil slick that marks the submarine's position. At 1140, TAYLOR attacks with a barrage of twenty-four 7.2-inch Mk. 10 "Hedgehog" projector charges that sink the submarine - probably I-13 - at 34-28N, 150-55E.

31 July 1945: 

At 1033, USN code-breakers intercept and decrypt a message that reads: "Since the I-13 sortied from Ominato July 11th, have had no communication with her. This unit ----- has no knowledge of what happened to her."