The vessel is a violator of the 'Crimean sanctions' and is involved in the interests of the russian ministry of defence in supplying oil products to the Syrian group of russian troops.
It was first recorded by the BlackSeaNews Monitoring Group of the Black Sea Strategic Studies as a violator of the Crimean sanctions on 12.05.2017, when it delivered 6.5 thousand tonnes of diesel fuel from Novorossiysk to the Feodosia oil depot (at that time, the Kerch Bridge did not exist, and fuel was delivered to the temporarily occupied Crimea by sea). In total, at least 21 such flights were recorded before the Kerch Bridge was put into operation (May 2018). The vast majority of voyages to the temporarily occupied Feodosia were carried out with the AIS signal switched off, while the vessel officially reported that the port of destination was the port of Kavkaz (russia).
It regularly transported petrol and diesel fuel from the Feodosia oil depot to the Syrian port of Tartus to supply the russian troops in Syria, including the "Syrian squadron" of the russian Navy. It usually switched off its AIS in the Mediterranean Sea on the approach to Cyprus, then proceeded to Tartus with the AIS signal switched off, and was repeatedly photographed from space in the port of Tartus at the russian Navy naval base. 04.08.2023 The Sig was damaged after an attack in the Black Sea south of the Kerch Strait.
The involvement of the Sig, which belongs to the fleet of the sanctioned russian shipping company Transpethrochart LLC, in the supply of fuel to russian troops in Syria came after the imposition of sanctions on Sovfracht JSC, one of the largest independent freight forwarding companies in russia, which acts as a key node in the military transport network of russian cargo vessels delivering North Korean weapons to military facilities, which are then transported to weapons depots on russia's western border for use in the war against Ukraine.
In September 2019, USA imposed sanctions on the "Sig" tanker for providing material support to the sanctioned Sovfracht JSC. Despite the sanctions, the vessel has been freely navigating the Bosphorus Strait.