Japanese submarine chaser CH-4

CH-4 was a No.4-class submarine chaser of the Imperial Japanese Navy during World War II.

History
CH-4 was laid down on 1 January 1938 at the Sakurajima Zosensho shipyard in Osaka, launched on 13 September 1938, and completed and commissioned on 28 December 1938.

She participated in the invasion of the Northern Philippines (Operation "M") in December 1941 where she was assigned to Sub Chaser Division 21 (SCD 21) led by Commodore Ota along with JAPANESE SUBMARINE CHASER CH-5, JAPANESE SUBMARINE CHASER CH-6, JAPANESE SUBMARINE CHASER CH-16, JAPANESE SUBMARINE CHASER CH-17, and JAPANESE SUBMARINE CHASER CH-18. SCD 21 was at the time assigned to Rear Admiral Hirose Sueto's 2nd Base Force under Vice Admiral Ibō Takahashi's Third Fleet. She served mostly on escort duty during the war. On 26 August 1943, while escorting transport Amagisan Maru and fleet oiler Tsurami, she was attacked off the coast of Palau by USS Tunny (SS-282) captained by Lieutenant Commander James A. Scott; Scott was forced to abandon his efforts after CH-4 damaged his submarine with depth charges.

On 13 August 1945, she hit a mine in the Surabaya Channel and never returned to duty due to the end of the war in August 1945. She was surrendered to the Allied forces at Bandjermasin, Borneo and later sold to a third party. She was removed from the Navy list on 3 May 1947.