TASS Russian news agency

“During the first stage in the Gulf of Finland, the submarine will undergo speed and maneuverability trials. The shipbuilders will conduct trim dive and inclining tests, check the sonar system, navigation and communication equipment, test the mast-hoisting gear. The first stage of the shipbuilders sea trials is planned to be completed in late December 2021,”

Admiralty Wharves Shipyard

The Admiralty Wharves Shipyard has been building the Kronstadt submarine under an upgraded project, taking into account the results of the operational evaluation of the lead sub, the Sankt Peterburg (B-585). The submarine’s onboard equipment control, propulsion and navigation systems have been modernized.

Russia's 2nd Lada-class Submarine 'Kronstadt' Starts Sea Trials
Admiralty Wharves Shipyard picture.

Project 677 Lada-class submarines are fourth-generation diesel-electric subs. Today, they are considered to be the most advanced and promising diesel-electric submarines in terms of their combat effectiveness and other tactical capabilities.

The Admiralty Wharves Shipyard is the sole producer of submarines of the type.