# Russian submarine B-237

Rostov-na-Donu (B-237) (Russian: Б-237 «Ростов-на-Дону») is an improved Kilo–class attack submarine of the Russian Navy, built in 2014. It became part of Russia's Black Sea Fleet.
The submarine was heavily damaged in a Ukrainian attack on 13 September 2023. It was later restored, but was reportedly hit again and allegedly sunk on 2 August 2024.

## Ship

Rostov-na-Donu is a diesel-electric submarine of the Improved Project 636.3 class of modern Russian ships. B-237 was built in Saint Petersburg shipyard, laid down on 21 November 2011, launched on 26 June 2014 and commissioned on 26 December 2014.

## History

The submarine is part of the Russian Black Sea Fleet but had been deployed in the Mediterranean Sea in the early 2020s. The submarine returned to the Black Sea in February 2022, passing the Bosporus on 13 February. With Rostov-na-Donu, the Russian Black Sea Fleet had four Improved Kilo–class submarines equipped with Kalibr land-attack missiles deployed in the Black Sea as of February 2022, at least three of which were believed to be active.

### 13 September 2023 attack

On 13 September 2023, the Russian-appointed governor of Sevastopol Mikhail Razvozhaev said that Sevastopol Shipyard, belonging to Sevmorzavod, had been struck by a Ukrainian "missile attack" at 2 am, causing a large fire. The Russian MoD said that ten cruise missiles had been fired, of which seven were shot down. The attack also involved three "maritime drones", which were said to have been destroyed. The Ministry said, "As a result of being hit by enemy cruise missiles, two ships under repair were damaged". At least 24 people were reported injured. The ships damaged were the landing ship Minsk and Rostov-na-Donu. Ukraine said the two ships were "likely damaged beyond repair". The Russian government denied this, and said they would be repaired and returned to full operational status. Based on open-source imagery, the UK Ministry of Defence assessed that the submarine had "likely suffered catastrophic damage".
On 18 September, two images were leaked online of the damage to Rostov-na-Donu, which appeared to be extensive. Two large breaches in the hull of the submarine could be seen, one around the midpoint of the starboard side to the rear of the conning tower and another on the top bow. Due to the nature of the damage, it was assessed that the submarine would be out of action for the duration of the war due to the closing of the Dardanelles Straits to all foreign warships at the beginning of the Russian invasion of Ukraine in accordance with the terms of the Montreux Convention. The submarine would need to be transported to the Admiralty Shipyards in Saint Petersburg to be repaired; however it is assessed to be more practical for a new submarine of the class to be constructed due to the extensive repairs that would be required.

### 2 August 2024 attack

Ukrainian forces claimed Rostov-na-Donu "sank on the spot" after a drone and missile strike on Sevastopol that also damaged an S-400 launcher. The submarine had been repaired after the 2023 attack, and was undergoing testing off Sevastopol. The British Ministry of Defense stated that it was, 'highly likely' that the submarine was sunk as Newsweek published satellite imagery alleging the submarine was replaced by a decoy with the genuine submarine partially hidden beneath a tarp nearby.