PLAN FOR INCHON ASSAULT
BLUE Beach Two, connected to One by the drainage ditch, also extended 500 yards. Like RED Beach it was fronted by a rock sea wall. On the right half, the wall retained one side of a narrow ramp that jutted southward like a long index finger. Behind the ramp lay a cove, its shoreline at a right angle to the sea wall. During the assault, Marines would scale the waterfront of BLUE Two from LVTs, while the cove around the corner on the right, unofficially dubbed “BLUE Beach Three,” was investigated as a possible supplementary landing site.[131]
[131] Ibid.; and Col T. L. Ridge ltr to authors, 11 May 55.
Preceded by a wave of LVT(A)s of Company A (Reinf), 56th Amphibian Tractor Battalion, USA, the 2d and 3d Battalions, 1st Marines, would land abreast on BLUE One and Two respectively. With two companies initially in the assault, each of the infantry battalions was to drive forward and secure its portion of the O-1 Line. This four-mile arc bent inland as far as 3,000 yards to include four main objectives, assigned as follows:
| 2d Battalion (BLUE One) | |
| ABLE | A critical road junction about 1,000 yards northeast of the beach. |
| DOG | Hill 117, 3,000 yards northeast of the beach, commanding Inchon’s back door and the highway leading to Seoul, 22 miles away. |
| 3d Battalion (BLUE Two) | |
| CHARLIE | The seaward tip of Hill 233, a long east-west ridge beginning 1,500 yards southeast of the beach and blocking off the stubby Munhang Peninsula, which projected southward. |
| BAKER | A small cape, topped by Hill 94, to the right of Objective Charlie and flanking BLUE Beach.[132] |
[132] 1st MarDiv OpnO 2-50; and 1st MarDiv SAR, Annex Peter Peter.
While a question may arise as to the choice of landing the 5th Marines in the very heart of Inchon, it must be remembered that immediate seizure of the port facilities was vital to the success of the operation. Hitting the beaches at only two-thirds infantry strength, the 1st Marine Division could not swell to the overwhelming proportions of an invasion force. A modern harbor for rapid build-up and exploitation by X Corps figured inherently in MacArthur’s strategy.
If RED Beach thus constituted the critical objective, then the selection of BLUE Beach for a supporting landing followed in logical sequence. Once on the O-1 Line, the 1st Marines would flank the single overland approach to the peninsular seaport, thereby presenting the NKPA garrison with the grim alternatives of early flight, capitulation, or strangulation. Without this leverage on Inchon’s flank and rear, the 5th Regiment could easily be swallowed up by two square miles of dense urban area.
Four assault battalions would have two hours of daylight in which to bridge the gap between planning and reality. From overhead and behind they could expect a preponderance of heavy fire support, but ahead lay enemy and hydrographic situations still clouded by question marks.