I-39 was an Imperial Japanese Navy B1 type submarine. Completed and commissioned in 1943, she served in World War II, operating in support of Japanese forces in the Battle of Tarawa before she was sunk in November 1943. Construction and commissioning I-39 was laid down on 19 June 1941 by at the Sasebo Navy Yard at Sasebo, Japan, with the name Submarine No. 152. Renamed I-39 by the time she was launched on 15 April 1942 and provisionally attached to the Yokosuka Naval District that day, she was completed and commissioned on 22 April 1943. Service history Upon commissioning, I-39 was attached formally to the Yokosuka Naval District and assigned to Submarine Squadron 11 for work-ups. With those completed, she was reassigned to Submarine Division 14 in Submarine Squadron 8 in the Submarine Advance Force on 20 July 1943. She departed Yokosuka on 21 July 1943 and arrived at Truk on 27 July 1943. First war patrol On 2 August 1943, I-39 set out from Truk on her first war patrol, with a patrol area in the New Hebrides. She was depth-charged briefly by a destroyer north of Espiritu Santo on 7 August 1943, and on 29 August 1943 two destroyers sighted and pursued her, but she suffered no damage in either encounter. On 2 September 1943, I-39 sighted a convoy of three transports escorted by four destroyers. She fired two torpedoes, both of which exploded close astern of the attack transport , which was carrying the New Zealand Army′s 3rd Division from Port Vila on Efate to Point Cruz on Guadalcanal. A destroyer attempted a counterattack, but failed to locate I-39. On 10 September, I-39 sighted an unescorted transport heading toward Espiritu Santo at 09:50, but could not get within torpedo range of her. On 11 September I-39 sighted another unescorted transport east of Espiritu Santo at 05:05 and two transports escorted by a destroyer at 18:10, but made no attacks. I-39 was east of Espiritu Santo on 12 September 1943 when she sighted the United States Navy fleet tug towing the 6,600-ton gasoline barge YOGN-42 from Pago Pago in American Samoa to Espiritu Santo. Mistaking Navajo for a British light cruiser, she hit Navajo with a single torpedo amidships on her starboard side. Navajo exploded and sank by the bow in two minutes at with the loss of 17 members of her crew. While returning to Truk, I-39