小澤治三郎
At 0713 on 9 December, Force Z passed the Anambas Islands to the east, and turned to a new course of 330 degrees, later changing to 345 degrees. Force Z was overflown by two Japanese reconnaissance aircraft, but not reported, before being spotted by Japanese submarine "I-65" at 1400 on 9 December, which shadowed the British ships for five hours, radioing their positions. Phillips was unaware he was being tracked. After this contact report, Vice Admiral Jisaburō Ozawa, in command of the invasion force, ordered most of his warships to escort the empty transports back to Cam Ranh Bay in southern Vietnam.