The Project 122bis small submarine chasers were designed in 1943–1944 as a replacement for the existing Project 122A, addressing key shortcomings of the earlier designs, particularly the poor seakeeping ability (being improved to withstand conditions up to Beaufort force 9, compared to force 7 previously) and outdated sonar systems. Due to the challenges posed by World War Two, the first ship was not laid down until June 1945. However, production eventually reached around 30 vessels per year, with a total of 227 units launched between 1946 and 1955. The design ultimately proved to be only a transitional solution, as the hull lacked sufficient speed and the vessel’s own noise rendered it incapable of detecting submarines at speeds exceeding 10 knots. Vessels of the class served in multiple Warsaw Pact navies as well as in China. Most were retired by the 1970s, although some remained in service until the 2010s.

The MPK Pr.122bis was introduced during Update 1.87 "Locked On" as a reward for the Battlefield Engineer event. It features good survivability thanks to its large crew complement and a large hull, along with a heavier main armament than the MPK Pr.122A, trading a 76 mm gun for an 85 mm one, which offers higher damage but significantly lower rate of fire and muzzle velocity. This makes it more effective against other sub-chasers but less capable of handling small, agile boats. To compensate for this, the vessel is equipped with two additional 37 mm guns on the aft section, providing a significant firepower advantage over the tech-tree equivalent.