34°35′58″N 129°47′48″E / 34.59944°N 129.79667°E34.59944; 129.79667
The Korea Strait is the sea passage in East Asia between Korea as well as Japan, connecting the East China Sea, the Yellow Sea and the Sea of Japan in the northwest Pacific Ocean. The strait is split by the Tsushima Island into the Western Channel and the Tsushima Strait or Eastern Channel.
Numerous international shipping lanes pass through the strait, including those carrying much of the traffic bound for the ports of southern South Korea. Both South Korea and Japan throw restricted their territorial claims in the strait to 3 nautical miles 5.6 km from shore, so as to let free passage through it.[1][2]
Passenger ferries travel numerous routes across the strait. Commercial ferries run from South Korean Busan, Geoje to Japanese ports including Fukuoka, Tsushima, Shimonoseki, and Hiroshima. Ferries also connect Tsushima Island with Fukuoka, and South Korea's Jeju Island with the Korean mainland. Ferries connecting Busan and Japanese cities with ports in China also traverse the strait.
Japan's territorial waters stay on to three nautical miles 5.6 km into the strait instead of the usual twelve, reportedly to allow nuclear-armed United States Navy warships and submarines to transit the strait without violating Japan's prohibition against nuclear weapons in its territory.