Ships
- IJN Atago Captain from 1 December 1942
Nobuki Nakaoka was a captain of the Imperial Japanese Navy who spent most of his career in the submarine service before taking a heavy cruiser. He assumed command of Atago on 1 December 1942 and was killed aboard her at Rabaul on 5 November 1943. The navy advanced him to rear admiral on the day he died.
He belonged to the 45th class of the Naval Academy and stood 40th among 89 graduates. He afterward attended the gunnery, torpedo, and submarine schools, and in November 1929 he entered the Naval Staff College, where he completed the 29th class. On 1 December 1931 he became commanding officer of the submarine I-4. In October 1932 he shifted to the submarine I-57.
From November 1933 he taught at the submarine school. In November 1934 he joined the staff of Submarine Squadron 2, and a year later he moved to the staff of Submarine Squadron 1. In December 1936 he went to Manchuria as a staff officer of the naval department there. In November 1938 he was named assistant naval attaché at the Japanese embassy in Manchukuo. The following month he returned to command afloat as commander of Submarine Division 24. He then led Submarine Division 28 from March 1939, Submarine Division 19 from November 1939, and Submarine Division 12 from October 1940.
On 1 July 1942 Nakaoka was appointed captain of the training cruiser Katori. On 28 November he was attached to the Second Fleet, and on 1 December he relieved Matsuji Ijuin as captain of the Takao-class heavy cruiser Atago. The cruiser had entered the Pacific War as flagship of Vice Admiral Nobutake Kondo, commander of the Second Fleet, and under Nakaoka she remained one of that fleet's principal ships, moving between Truk and home waters through 1943.
In July 1943 Atago left Truk with the heavy cruiser Takao and reached Yokosuka late in the month. In mid-August she sailed from Kure for Truk again with a force that included battleships, under Admiral Mineichi Koga, commander of the Combined Fleet. She was at Truk once more in late October. After Allied troops landed at Cape Torokina on Bougainville on 1 November, Vice Admiral Takeo Kurita brought a cruiser force down from Truk to Rabaul with his flag in Atago. The ships entered the harbor on the morning of 5 November.
That morning aircraft from the American carriers Saratoga and Princeton struck the ships while they lay in the harbor. Three bombs burst close along Atago. A splinter from one of them hit Nakaoka on the bridge and killed him. The same near misses opened a large hole in the hull beside the port torpedo tubes and killed and wounded other men of the crew. Atago was kept afloat and later returned to the fleet. She was lost on 23 October 1944 in the Palawan Passage, under a later captain, when the submarine Darter torpedoed her at the start of the Battle of Leyte Gulf.