Buyan-class

The Buyan class, designated Project 21630 and Project 21631, is a series of small artillery and missile ships developed by the Zelenodolsk Design Bureau for the Russian Navy. The class succeeded the Nanuchka class and was subsequently followed by the Karakurt class. Construction began in 2004 at the Almaz Shipbuilding Company and Zelenodolsk Plant Gorky. The series includes the domestic Buyan-M subclass and an export variant designated Project 21632 Tornado.

The vessels are designed for littoral zone operations to protect coastal areas and national economic zones. Due to their shallow draft, the ships can operate in shallow sea areas and navigate Russia's internal waterway system, including the Moscow Canal and the Volga River. The initial Project 21630 design functions as a gunboat or monitor, while the Project 21631 Buyan-M is an enlarged guided-missile variant. The Buyan-M incorporates stealth technology and a vertical launching system (VLS) for anti-ship cruise missiles. This design allows the ships to deploy cruise missiles from inland river systems, a capability that placed them outside the restrictions of the Intermediate-Range Nuclear Forces (INF) Treaty regarding land-based missiles. Propulsion is provided by a combined diesel and diesel (CODAD) arrangement driving a pumpjet system.

The class entered commission in 2006, with vessels deployed to the Caspian Flotilla, Black Sea Fleet, and Baltic Fleet. Units of the Caspian Flotilla conducted long-range combat strikes in October and November 2015, launching cruise missiles against targets in Syria. In 2016, units deployed to the Mediterranean Sea for strike operations before being reassigned to the Baltic Sea. The Russian Navy has frequently utilized inland waterways to transfer these vessels between its western fleets and the Caspian Flotilla.

Vessels of the class have been involved in various combat operations and incidents since 2022. A Buyan-class ship conducted missile strikes against an arsenal in Ukraine in March 2022. During the same year, the Velikiy Ustyug sustained damage following an attack. In April 2024, a fire occurred onboard the Serpukhov while in port at Baltiysk; Ukrainian military intelligence attributed the event to a sabotage operation. In November 2024, a drone strike on the Kaspiysk naval base reportedly damaged a vessel of the class. In 2025, the Vyshniy Volochyok was damaged in a collision with a civilian tanker while performing evasive maneuvers against drones, and the Grad was reported damaged on Lake Onega while transiting inland waterways.