6th Fleet (Imperial Japanese Navy)
Despite these advantages, IJN submarines achieved remarkably little during World War II primarily having in hindsight suffered from the antiquated strategy of the Imperial Japanese Navy General Staff, who viewed submarines as little more than scouts whose main role was to locate and shadow enemy naval task forces in preparation for a decisive surface conflict. Maybe the IJN General Staff was slow to change as the submarines were generally slow to dive, easy to track with radar and sonar, difficult to maneuver underwater, and less sturdy than their German U-boat counterparts.
Japanese submarine tender Karasaki
At the end of 1904, "Karasaki Maru" was sent to the Yokosuka Naval Arsenal for conversion into a submarine tender. She was officially commissioned into the Imperial Japanese Navy on 4 July 1905. On 8 March 1906, she was renamed "Karasaki", and was officially re-designated as a torpedo boat tender. In August 1912, the Imperial Japanese Navy abolished the torpedo boat tender classification, and "Karasaki" was re-designated as a second-class "kaibokan". However, the designation of torpedo boat tender was revived in April 1920. From 1924, "Karasaki" was then assigned to the submarine training school at Kure Naval District, and from 1 December 1924, was again officially designated as a submarine tender.