Poti class corvettes had a propulsion system composed of two gas turbines that fed two propellers installed in a kind of tunnels mounted on the stern. Two air compressors connected to these tunnels added extra thrust to the propellers. This system was also installed on the Mirka class frigates, although it was a very noisy and unreliable system.The armament of the first units was composed of two 57mm guns installed in an open twin turret, two RBU-2500 anti submarine rocket launchers and three 533mm torpedo tubes in a triple assembly, but this armament would be modified shortly after.Most of the Poti class corvettes had two 57mm guns installed in an enclosed twin turret, two RBU-6000 anti submarine rocket launchers and two or four 406mm torpedo tubes. The main improvement was received when the RBU-6000 launcher was installed. This new launcher had a range of 6 km instead of 2.5 km of the previous ones.Despite the large number of ships built, in addition to the Soviet Navy only the Romanian and Bulgarian Navies had them in service. Bulgaria received six vessels from the original variant and Romania received three ships from the “Project 204E” modified version with more powerful ASW armament.
