No.13-class submarine chaser

The No.13 class submarine chaser (第十三号型駆潜艇,, Dai 13 Gō-gata Kusentei) were a class of submarine chasers of the Imperial Japanese Navy (IJN), serving during and after World War II; there were three sub classes, however the IJN's official document calls all of them the No.13 class.

• In 1938 the Soviet Union strengthened its Pacific Ocean Fleet, increasing the number of submarines it possessed; the No.13 class was designed to counter this potential threat to Japanese shipping.

• Project number K8. 15 vessels were built in 1939-42 under the Maru 4 Programme (Ship # 180 – 183) and the Maru Rin Programme (Ship # 184 – 194). And after the Maru Rin Programme vessels were equipped with a kitchen and food storage between bridge and the chimney for a long cruise.

• Project number K8B. 31 vessels were built in 1941-44 under the Maru Rin Programme (Ship # 221 – 232) and the Maru Kyū Programme (Ship # 440 – 458). They abolished a slant of stern for mass production.

• Project number K8C. 3 vessels were built in 1943-44 under the Kai-Maru 5 Programme (Ship # 5341, # 5342 and 5344). They were changed inner hull design from the No.28 class. Therefore, there is not a difference of appearances.

• 
  No.30 on 13 May 1942
• 
  No.23 or No.38 on 16 September 1945

• Monthly Ships of the World, Special issue Vol. 45, "Escort Vessels of the Imperial Japanese Navy","Kaijinsha"., (Japan), February 1996
• Model Art Extra, No. 340 "Drawings of Imperial Japanese Naval Vessels Part-1","Model Art Co. Ltd". (Japan), October 1989
• The Maru Special, Japanese Naval Vessels No. 49, "Japanese submarine chasers and patrol boats","Ushio Shobō". (Japan), March 1981
• 50-year History of Harima Zōsen, Harima Zōsen Corporation, November 1960