Insurance costs for ships carrying oil across the Black Sea rose from about $200,000 to $2.5 million per vessel in recent months, according to OilPrice.

According to the publication, the increase reflects mounting risks to commercial shipping after repeated attacks on vessels and port infrastructure. On October 6, drones struck two commercial vessels, sinking the Togo-flagged Alfa Watan and damaging the Palau-flagged Able; all 18 crew members aboard the Able were rescued.