Departing Manitowoc 20 August, USS KETE (SS-369) sailed via New Orleans to Panama. Arriving 5 September, she trained with SubRon3 until 28 September; then the new submarine sailed to Pearl Harbor, arriving 15 October, and steamed westward on the 31st for her first war patrol.
She topped off her fuel at Midway 4 November and reached her assigned patrol area in the East China Sea on 15 November in company with USS SEA LION (SS-315). Harassed by heavy weather and nonfunctioning bow planes, she sailed 19 November for Saipan, where she arrived the 24th. She departed Saipan with USS KRAKEN (SS-370) on 24 December and resumed her war patrol north of Okinawa 4 days later. Despite prolonged periods of heavy weather, she made lifeguard patrols off the central Ryukyus from 1 January to 27 January 1945 searching for American fliers downed during air strikes on the Ryukyus. After gathering vital weather data, she sailed to Guam and arrived 30 January for refit.
Departing Guam on 1 March 1945, KETE headed for her second war patrol during in the vicinity of Nansei Shoto (island chain). In addition to performing a normal patrol, KETE had orders to submit special weather reports, and to carry out rescue service during an air strike by carrier based planes.
On the night of 10 March 1945, KETE reported having sunk three medium sized freighters on the previous night. She reported on the night of 14 March that she had fired four torpedoes which missed a small enemy cable laying vessel, and that she had only three torpedoes left, KETE was directed to depart her area on 20 March, and proceed to Pearl Harbor for refit, stopping in Midway enroute for fuel. On 19 March, she acknowledged receipt of these orders. On 20 March she sent in a special weather report from position 29!-38'N;130!-120'E. This was the last message received from her. At normal cruising speed she should have arrived at Midway about 31 March 1945. When she was neither sighted nor heard from by 16 April 1945, she was reported as presumed lost.
Japanese information concerning antisubmarine attacks gained at the end of the war gives no positive evidence to what happened to KETE; none of the attacks on U.S. submarines occurring within the period from 20 March to 31 March 1945, was made in a position in which KETE was likely to be.
There were a few minelines in the Nansei Shoto Chain, but since KETE was already east of the islands at the time of her last message on 20 March and was heading home, loss through a mine is considered highly improbable. It in now known that a number of enemy submarines were in the area through which KETE was required to pass enroute to Midway. RO-141 was sunk east of Okinawa by a U.S. destroyer on 23 March 1945, and two other Japanese submarines were sunk southeast of Okinawa near this date. Conditions attendant to KETE's loss suggest the likelihood that one of these submarines might have torpedoed and sunk her and been unable to report the attack before being sunk. Thus, KETE must be considered probably a loss due to an unreported enemy attack. She is credited with sending three medium freighters, total ing 12,000 tons, to the bottom on this last patrol. During her first patrol, conducted in the East China Sea, KETE encountered no enemy targets.
KETE received one battle star for World War II service.