And of course, for the other perspective from Pyongyang, here is THEIR take of where the lines are. Note Daecheon Island will show as Taechon island, on the left:
And here is a portion of the 1953 Armistice Agreement between the UN Forces on one side, and the Norks and ChiComs on the otherr side: "...TAECHONG-DO (37°50'N, 124°42'E) , SOCHONG-DO (37°46'N, 124°46'E) , YONPYONG-DO (37°38'N, 125°40'E) , and U-DO (37°36'N, 125°58'E) , which shall remain under the military control of the Commander-in-Chief, United Nations Command. All the islands on the west coast of Korea lying south of the above-mentioned boundary line shall remain under the military control of the Commander-in-Chief, United Nations Command..."
Text of 1953 Armistice Agreement