8) The Navy also lifted the Republic of Korea (ROK) I Corps from Songjin to Hungnam, where it was reembarked and lifted to Bokuko Ko.
Militarily usable ports, shown on map 1, then comprised, on the west coast, Chinnampo, Inchon, and Kunsan, dominated by the great tidal range of the shallow Yellow Sea; on the east were Songjin, Hungnam, Wonsan, and Pusan, with deep water just offshore.
Facing the prospect of simultaneous retrograde movements by Eighth Army on the west coast and by X Corps on the east, Doyle retained overall command of the redeployments but directed Amphibious Group 3, under Rear Admiral Lyman Thackrey, to attend to Eighth Army at Chinnampo and Inchon, leaving Amphibious Group 1, under his direct command, to support X Corps at Songjin, Wonsan, and Hungnam.
This meant that Thackrey conducted operations at Chinnampo and Inchon largely independently, while Doyle commanded efforts at Songjin, Wonsan, and Hungnam.
04 left Wonsan on December 6 to lift a Korean corps from Songjin to Hungnam, completing embarkation December 9.
The 1st Marine Division departed Inchon on 12 October and arrived off the east coast only to discover that under Soviet supervision, the enemy had mined Changjon Koje, Hungnam, songjin
and Wonsan in the interim.