yet arrived. At 07:13 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 14:00 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. I-65's amplifying report, confirming the presence of British battleships, reached 22nd Air Flotilla headquarters two hours later. At that time, their aircraft were in the process of loading bombs for an attack on Singapore Harbour, but they immediately switched to torpedoes. The bombers were not ready until 1800 hours. The report also prompted the Japanese 2nd Fleet, Southern (Malay) Force's Main Body, to sortie south from Indochina to intercept Force Z. The fleet consisted of the battleships Kongō, Haruna, three cruisers and eight destroyers. They were joined by four cruisers of Cruiser Division 7 and one light cruiser, four destroyers of Destroyer Squadron 3. The cruiser Chōkai, flagship of Vice Admiral Ozawa, was also ordered south to find Force Z. About 1730, just a half-hour before sunset, Force Z was spotted by three Aichi E13A seaplanes, which had been catapulted off the Japanese cruisers Yura, Kinu and Kumano, which were escorting the transports. These aircraft continued shadowing. At about 18:30, Tenedos was detached to return to Singapore, because she was running low on fuel, with instructions to contact Rear Admiral Arthur Palliser, detailed to act as liaison to RAF in Malaya, Phillips' intention was no longer to attack Singora, although Phillips changed course at 19:00 toward Singora, to deceive the shadowing aircraft, then south toward Singapore at 20:15, when darkness covered him. Tenedos dutifully reported at 20:00, thereby preserving the secrecy of Phillips' position. A night air attack was attempted by the Japanese because they feared that the British would find the convoy, but bad weather prevented them from finding the ships and they returned to their airfields at Thủ Dầu Một and Saigon about midnight. Return to Singapore That night, one of the Japanese seaplanes dropped a flare over the Japanese heavy cruiser Chōkai, having