At least 65 oil tankers have dropped anchor at multiple locations, including off the coasts of China and Russia, since the United States announced a new sanctions package on Jan. 10, ship tracking data showed on Monday.
Five of those tankers were stationary off Chinese ports and a further seven dropped anchor off Singapore, with others halting near Russia in the Baltic Sea and the Far East, according to Reuters' analysis based on MarineTraffic and LSEG ship tracking data.
The U.S. Treasury on Friday imposed sanctions on Russian oil producers Gazprom Neft and Surgutneftegaz, as well as on 183 vessels that have shipped Russian oil, as it targets the revenues Moscow has used to fund its war with Ukraine.
The halt in trading for these tankers adds to further pressure on vessels already hit by previous U.S. sanctions.
These include another 25 oil tankers that were stationary around various locations, including off Iranian ports and also near to the Suez Canal, ship tracking analysis showed on Monday.
Some ports have already acted before the latest measures, adding further strains. Shandong Port Group banned tankers under U.S. sanctions from calling at its ports, traders said last week.
Analysts estimated that around 10% of the global oil tanker fleet was subject to US sanctions.
"The effect of these sanctions should be supportive to the tanker market as vessel supply in the broader fleet shrinks, but the real potential strength would come once other exporters make up for the lost volumes," Jefferies analyst Omar Nokta said in a note on Monday.
Average daily earnings for supertankers jumped over 10% on Monday versus the previous day to around $26,000, according to market estimates.
Some charterers already tried to secure ships on Friday after the sanctions were announced, pointing to the tightening supply of ships.
"Increased demand for exports to India and China from outside Russia will increase non-sanctioned tanker demand," trade analytics platform Kpler said on Monday.
