In the unique situation of the Korean Peninsula, which is still technically in a state of war, maritime issues are increasingly becoming critical in the relations between South Korea and North Korea. While cooperation in maritime affairs has helped to ease tensions and paved a way to reconciliatory efforts, maritime disputes adjacent to the Northern Limit Lines in the West and East Seas and maritime security issues such as South Korea's engagement in the Proliferation Security Initiative remain a source of conflict. This article looks at maritime affairs on the Korean Peninsula—a leading area of cooperation between the South and the North as well as a potential conflict flash point.