Imperial Japanese Navy Ro-29 class commerce raider submarine, c. 1930, being overflown by Imperial Japanese Navy carrier-based Mitsubishi 2MR4 reconnaissance fighter planes.

See also:
I.J.N. O-5 (former SM UC-99) war prize submarine, c. 1920.
“Jingei”-class submarine tender & Type B1- and Type C-class submarines, c. 1941.
I.J.N. I-71 K6-class submarine & submarine depot ship “Taigei”, c. 1935.

“Ro-29, originally named Submarine No. 68, was an Imperial Japanese Navy Kaichu-type submarine of the Kaichu V (Toku Chu) subclass. She was in commission from 1923 to 1936 and saw service in the waters of Formosa and Japan.

“The submarines of the Kaichu V sub-class were designed for anti-shipping operations and carried more fuel and had greater range and a heavier gun armament than preceding Kaichu-type submarines.

“Ro-29 was laid down as Submarine No. 68 on 2 June 1921 by Kawasaki at Kobe, Japan. Launched on 5 December 1922, she was completed and commissioned on 15 September 1923. Upon commissioning, Submarine No. 68 was attached to the Sasebo Naval District, to which she remained attached throughout her active career.

“On 1 June 1924, No. 68 was assigned to both Submarine Division 25 — in which she spent her active career — and the Mako Defense Division headquartered at Mako in the Pescadores Islands. She was renamed Ro-29 on 1 November 1924. On 1 December 1926, she was reassigned to the Sasebo Defense Division, headquartered at Sasebo, Japan. Her service in the Sasebo Defense Division ended on 15 November 1934, after which she served as a unit of Submarine Division 25 in the Sasebo Naval District.

“Ro-29 was decommissioned and stricken from the Navy list on 1 April 1936.”

– Wikipedia