No.4-class submarine chaser

The No.4 class submarine chaser (第四号型駆潜艇,) was a class of submarine chasers of the Imperial Japanese Navy (IJN), serving during and after World War II. 9 vessels were built in 1937-39 under the Maru 3 Programme.

Design

 * Project number was K7. The No.4 class submarine chaser was reinforced model of the No.3 class. They lifted freeboard. Other general placement were same as No.3 class.
 * Their design was elaborate, because the Navy Technical Department (Kampon) devoted itself to making them small. However, their designs were not able to accept the reinforcement of anti-aircraft guns and depth charges.