Strait of Tatar (also Mamiya Strait and Strait of Nevelskoi) is a 6 km wide and 4-20 m deep strait dividing the Russian island of Sakhalin from the mainland Asia, connecting the Sea of Okhotsk on the north with the Sea of Japan on the south.
The name Tatar, or Tartary comes from an out-of-date name for Asia. In the Japanese literature, the strait is named after Mamiya Rinzo, who sailed the strait in 1808, while Russian authors prefer to name it after Admiral Nevelskoi, who explored the area in 1848.