The Black Sea Fleet’s Project 636.3 diesel-electric submarine Rostov-on-Don will soon rejoin the Russian Navy’s permanent Mediterranean task force, a source in the defense industry told TASS on Wednesday, EDNews.net reports citing Syrian Observer.

“The submarine has been prepared for its long-distance deployment to the Mediterranean Sea. It will begin in the coming days,” the source said.

The source did not specify whether the submarine Rostov-on-Don would replace the Krasnodar submarine currently on its deployment in the Russian Navy’s Mediterranean Squadron or would join the task force.

Normally, two of the Black Sea Fleet’s six Project 636.3 submarines are deployed in the Mediterranean Squadron. Their deployment lasts an average of 18 months, while the crews are rotated every three months. From the previous pair, the submarine Stary Oskol left the Mediterranean Squadron for repairs at the Kronshtadt Marine Plant (part of Russia’s United Shipbuilding Corporation), while the Krasnodar is still staying in the Mediterranean Sea.

The submarine Krasnodar was earlier expected to follow the Stary Oskol and sail to the Kronshtadt Marine Plant for repairs.

The submarines Stary Oskol and Krasnodar joined the Russian Navy’s Mediterranean task force in April 2019. They replaced the Veliky Novgorod and Kolpino submarines, which had stayed in the Mediterranean after their inter-fleet transit from the Baltic Sea and then sailed to the Black Sea. Their crews were rotated every three months.