Japanese submarine Ro-38

Ro-38 was an Imperial Japanese Navy Kaichū type submarine of the K6 sub-class. Completed and commissioned in July 1943, she served in World War II and was sunk in November 1943 during her first war patrol.

Design and description
The submarines of the K6 sub-class were versions of the preceding K5 sub-class with greater range and diving depth. They displaced 1115 LT surfaced and 1447 LT submerged. The submarines were 80.5 m long, had a beam of 7 m and a draft of 4.07 m. They had a diving depth of 80 m.

For surface running, the boats were powered by two 2100 bhp diesel engines, each driving one propeller shaft. When submerged each propeller was driven by a 600 hp electric motor. They could reach 19.75 kn on the surface and 8 kn underwater. On the surface, the K6s had a range of 11000 nmi at 12 kn; submerged, they had a range of 45 nmi at 5 kn.

The boats were armed with four internal bow 53.3 cm torpedo tubes and carried a total of ten torpedoes. They were also armed with a single 76.2 mm L/40 anti-aircraft gun and two single 25 mm AA guns.

Construction and commissioning
Ro-38 was laid down as Submarine No. 204 on 20 June 1942 by Mitsubishi at Kobe, Japan. She was renamed Ro-38 on 1 November 1942, and was provisionally attached to the Maizuru Naval District that day. She was launched on 24 December 1942 and completed and commissioned on 24 July 1943.

Service history
Upon commissioning, Ro-38 was attached formally to the Maizuru Naval District, and on 31 July 1943 she was assigned to Submarine Squadron 11 for workups. On 31 October 1943 she was reassigned to Submarine Division 34 in the 6th Fleet, and she departed Maizuru bound for Truk that day. She arrived at Truk on 8 November 1943.

Ro-38 got underway from Truk on 19 November 1943 to begin her first war patrol, assigned a patrol area in the Gilbert Islands in the vicinity of Makin and Tarawa. The Japanese never heard from her again.

On 20 November 1943, the Battles of Makin and of Tarawa began with the U.S. landings on those atolls. That day, the commander-in-chief of the 6th Fleet, Vice Admiral Takeo Takagi, ordered Ro-38 and the submarines JAPANESE SUBMARINE I-19, JAPANESE SUBMARINE I-21, JAPANESE SUBMARINE I-35, JAPANESE SUBMARINE I-39, JAPANESE SUBMARINE I-40, JAPANESE SUBMARINE I-169, JAPANESE SUBMARINE I-174, and JAPANESE SUBMARINE I-175 to attack the U.S. invasion fleet off the atolls. On 26 November 1943, Takagi ordered I-19, I-40, I-169, and Ro-38 to form a patrol line north of Makin, with Ro-38 northeast of Makin at the eastern end of the line. The 6th Fleet ordered Ro-38 to move to a new patrol area southeast of Tarawa on 27 November 1943, and on 4 December 1943 it sent her orders to patrol between Tarawa and Canton Island. Ro-38 did not acknowledge any of these orders.

The circumstances of Ro-38′s loss are unknown. It is possible that the United States Navy destroyer USS Cotten (DD-669) sank her west of Tarawa on 24 November 1943. On 2 January 1944, the Imperial Japanese Navy declared her to be presumed lost off the Gilbert Islands with all 77 hands. She was stricken from the Navy list on 30 April 1944.