The USNS Pathfinder (T-AGS 60) oceanographic survey ship, which is owned by the Military Sealift Command and has a civilian crew and scientists on board, was anchored in the Sevastopol harbor from September 15 at the invitation of the Ukrainian government.
"The U.S. Pathfinder ship left Ukrainian territorial waters last night...The research vessel, with 42 crew members on board, is heading toward the Souda Bay port [Greece]," the UNIAN news agency quoted officials from the Ukrainian Border Guard Service as saying.
According to official statements, Pathfinder was searching for a ship which sank in the harbor during World War II.
The Soviet hospital ship Armenia was sunk on November 7, 1941 by German torpedo-carrying He 111 planes while the ship was evacuating refugees and wounded military and staff from Crimean hospitals. It is estimated that approximately 7,000 people died in the attack.
However, Russian intelligence believes that ships of the Pathfinder class could be used for reconnaissance and intelligence gathering purposes.
The Pathfinder is the last of the four U.S. vessels that arrived in the Black Sea in August-September to leave the region. The ships were sent to the Black Sea after the 5-day war between Russia and Georgia over South Ossetia.
On August 20, the Turkish government gave permission to three U.S. warships to enter the Black Sea as part of relief efforts in Georgia. They stayed in the region for 21 days, in line with the terms of the 1936 Montreux Convention, which governs passage through the Bosporus straits, and according to Washington have already left the Black Sea.
Russia's NATO envoy Dmitry Rogozin said on Wednesday that Russian warships would continue patrolling waters off the coast of Abkhazia until all U.S. ships leave the Black Sea.