Marine insurers are monitoring developments in the Baltic Sea after Russian authorities detained a Greek-owned oil tanker on Sunday, three senior market sources told The Insurer.

Russia detained the Liberia-flagged Green Admire as it was leaving the Estonian port of Sillamäe using a previously agreed route that crosses Russian territorial waters, Estonia’s Ministry of Foreign Affairs said in a statement on Sunday.

While one of the sources said the detainment may lead to some hardening in annual war risk premiums, another said this event by itself would be unlikely to move rates. However, they said there would be a significant upward rating impact if Russia began employing this tactic indiscriminately.

The Baltic Sea is not currently designated as a listed area by the Lloyd’s Market Association’s Joint War Committee, two senior war risk market sources said.

A Greek government official said the Green Admire had manoeuvred in Russian waters to avoid shallows and that Russian authorities had intercepted the vessel and moved it to a safe place to impose a fine.

“It is understood that this incident follows an attempt by the Estonian Navy to intercept the Gabon-flagged tanker JAGUAR in the Baltic Sea on May 13, 2025. Such incidents are not common and it is assessed that this is a specific retaliatory action,” Vessel Protect’s head of operations Munro Anderson told The Insurer.

The Green Admire was anchored near Russia’s Hogland Island at one point on Sunday afternoon, according to Marine Traffic, a website that tracks vessels. The website shows that, as of 9.17 a.m. BST on Tuesday, the vessel had sailed westward through the Gulf of Finland.
Source: Reuters