Standing orders required her to transmit by radio prior to entering a circle of radius 500 miles from Midway, and this report was expected by 6 May. When it was not received, a message ordering an immediate reply was repeatedly sent. No answer was received, and plane search along her expected course revealed nothing. As a result, she was reported lost on 12 May 1943. However, a special notation is made on the Japanese records to the effect that they are inaccurate for the month of April 1943.
Mines are normally ineffective in water that deep.
Operational casualties or mine explosions represent possibilities, but are not thought to be likely. On her first patrol she did no damage to the enemy. Her second, conducted between Manila and Surabaya, resulted in the sinking of two freighters. In her fourth patrol, in the Philippines, six attacks were made, but none resulted in damage to the enemy. She damaged a freighter on this run.