 He was subsequently executive officer on the cruiser in 1929, and then battleship in 1930.Promoted to captain on 1 December 1930, Komatsu commanded minelayer in 1931, submarine tender in 1932, light cruiser in 1933, and heavy cruiser in 1935.After his promotion to rear admiral on 1 December 1936, Komatsu commanded the 1st Submarine Squadron (SubRon 1) in 1937, and was Commandant of the Kure Submarine Warfare School in 1937.