After the first Pr.1204 entered service, the boat's weak armaments became apparent, prompting an upgrade. Eventually, in 1970, later-built boats were equipped with a casemate-mounted "Plamya" automatic grenade launcher, a 140 mm BM-14-17 multiple rocket launcher system, and the replacement of the 14.5 mm KPV heavy machine gun with the 25 mm 2M-3 autocannon. Even with these improvements, the Soviet Navy still felt the boat was underperforming, and nearly all were transferred to the Soviet Border Troops. Today, a small number of these boats remain in service with the Russian Navy and the Ukrainian State Border Guard.

Introduced during Update 1.79 "Project X" when the Soviet fleet was implemented into the game, the Pr.1204 late performs similarly to its predecessor, the Pr.191 armoured boat, but with improved speed, making it easier to navigate the map. Its main cannon, the 76 mm D-56TS, has both HE and APHE shells, capable of damaging light and heavily armoured targets. The 25mm 2M-3 autocannon can destroy light and medium armoured targets, as well as serve in an anti-aircraft role. It also has the 140 mm BM-14-17 MRLS, which is effective at destroying enemy destroyers. Additionally, it carries the same YAM-43 small coastal mine to block enemy paths to strategic points. One unique armament is the 30 mm "Plamya" grenade launcher, though it is not very effective beyond 1 km due to its limited range. Even if it hits the target, it does minimal damage due to its small explosive mass.