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Jump in AIS gaps mask Russian maritime activity

More Data Storytelling

Russia’s maritime trading patterns out of Sea of Azov ports is increasingly being obfuscated by vessels switching off their automatic identification systems (AIS).

While the frequency of ships switching off AIS in the Kerch Strait has been elevated since the outset of the military activity in Ukraine, the number of AIS gaps has risen dramatically since September.

There were 92 instances in August where a ship’s automatic identification system was switched off and back on while in the Kerch Strait, compared with 53 in the year-earlier period, according to Lloyd’s List Intelligence vessel-tracking data. 

By September, the number of AIS gaps being recorded had jumped to 196 instances and then 177 in October. Last month, Lloyd’s List Intelligence recorded at least 242 cases of AIS being switched off in the strait.

There are several legitimate reasons for a vessel to go ‘dark’, including passing through dangerous waters and issues with infrastructure, which would prevent AIS messages from being received. However, this backdrop was the same before September. 

The more common and well-established pattern to explain AIS gaps is that ships are deliberately turning off AIS to obfuscate their movements.

A few observations based on the data gathered are:

  • The number of distinct vessels recording AIS gaps, as well as the overall number of AIS gaps, in August-November 2022 is significantly up on the January-July 2022 period
  • The overall number of AIS gaps peaked at 242 in November. The monthly average for AIS gaps is 177 for August-November 2022, compared with 32 per month in January-July 2022, around 25 per month for the whole of 2021 and just 14 per month in 2020
  • Gaps between 96 and 168 hours have been the most common in August-November
  • Russian-flagged vessels are responsible for most of the gaps

Depending on the length of time the vessel tracking data is shut off, it is possible for ships to complete ship-to-ship transfers, call at a port in Crimea or travel to one of Russia’s Sea of Azov ports, such as Rostov-na-Donu.

There are two major ship-to-ship areas in the southern part of the Kerch Strait that have been operating for more than 20 years. Oil and oil products as well as bulk commodities, mainly grain, are transported there onto larger ships, which take the cargoes to foreign buyers.

It is difficult to pinpoint the driving force behind the gaps, but there are several factors likely contributing to this shift in pattern, according to analysts such as Yörük Işık from the Istanbul-based consultancy Bosphorus Observer. 

One potential explanation is that Russia’s plundering of Ukrainian grain has become busier and more sophisticated with increased levels of dark activity as a result - the vessels do not want to show they are coming from ports such as Mariupol and Berdyansk, for example.

Another potential scenario is that vessels in the area have realised that the wider world is tracking their movements and have gone dark as a result.