The Royal Navy announced that two ships had been following a Russian submarine which had entered the English Channel. Open-source intelligence (OSINT) had reportedly been tracking the vessel since the beginning of the month. Before entering the English Channel, the submarine along with a tug vessel had been shadowed by a French frigate. Once it left the Channel, the monitoring duties were taken over by a Belgian frigate. There is speculation that the Russian vessels may have breached a treaty.

On Sunday, July 19 the French frigate, FS Enseigne de vaisseau Jacoubet handed over monitoring duties of the Russian submarine to the Royal Navy. The submarine Krasnodar was followed by HMS Tyne from the coast of Ushant Island in Brittany. The River-class offshore patrol vessel followed Krasnodar through the English Channel.

#OSINT #submarine #ВМФ #Russia RFS Krasnodar (type 636.3 Kilo II class) and RFS Sergey Balk escorted by HMS Tyne through the English Channel 20-07-2020. pic.twitter.com/3QD3qQXRou

— bottema37 (@FrankBottema) July 21, 2020

As Krasnodar entered the Strait of Dover, the HMS Mersey took over monitoring duties from its sister ship HMS Tyne on Monday, July 20. HMS Mersey shadowed Krasnodar as it went into the North Sea. On Tuesday, July 21 the heavily armed Belgian warship F 930 Leopold took over from the HMS Mersey. The commanding officer of HMS Mersey praised the coordination between "allied ships and aircrafts" which have been involved in monitoring Krasnodar.

According to Forbes, Krasnodar and the support tug, Sergey Balk had been tracked by the OSINT. Since Krasnodar left Tartus in Syria on July 1, it had been followed closely by OSINT. Even though the Kilo-type submarine was invisible to the Automated Identification System (AIS), various methods were used to estimate the location of the vessel. OSINT analysts were able to track it as it passed close to Gibraltar on July 13.

Russian Navy tug Sergey Balk escorting Kilo Class SSK Westbound STROG off Europa Point #Gibraltar this afternoon Transit commenced at 13.30 local time #OPWest pic.twitter.com/zeYuVCatOG

— Michael J Sanchez (@key2med) July 13, 2020

The Daily Mail pointed out that the movement of Krasnodar could have been in breach of the Montreux Convention. The convention prohibits ships and submarines from going through the Bosphorus Straits, from the Black Sea to the Mediterranean unless they are going for repairs.

Krasnodar's journey through the English Channel came days after Russian warships were shadowed in the Channel.

Russian Submarine
A soviet submarine was tracked by two Royal Navy ships as it crossed the English Channel (representational image) FRED TANNEAU/AFP/Getty Images