Crimea reports that Russian forces boarded a boat of the Ukrainian Navy in Donuzlav Bay on the West coast of the peninsula.
Konstantin Olshanskii was one of the two boats still sailing with the Ukrainian flag.
Earlier, Kiev lost control of its last military base in the region, that of Feodosia.
The Acting President of Ukraine, Alexander Turchínov, ordered the withdrawal of the armed forces of the country of the peninsula to «save the lives of the staff».
The Russian Defense Minister, Sergei Shoigu, visited Crimea to inspect the troops and military installations. He is the officer of the army’s highest level who travels to Crimea since it was annexed by Moscow.