Late in December the rebuilt division, still short of arms and equipment, departed Hwachon with a mission of infiltrating through the UN lines to cut communications and harass rear installations of the Andong-Taegu area. Shots were exchanged with United Nations troops near Wonju, but General Lee Ban Nam and his troops contrived to slip to the east through the mountains. Stealthily moving southward, marching by night and hiding by day, they were soon in a position to heckle the rear of the X Corps sector. This advantage did not last long. Before they could strike a blow, the element of surprise was lost along with the three prisoners taken by the Marines. As the Marine units moved into their assigned zones, General Ridgway flew to Pohang to confer with General Smith. Not only did he express confidence that the Marines would soon have the situation well under control; he also suggested the possibility of small amphibious landings along the east coast. The purpose was to block a possible southward advance of the three CCF armies that had operated in Northeast Korea during the Chosin Reservoir campaign.[52] [52] Units of these armies, it may be recalled, were not identified again in the CCF order of battle before the middle of March 1951. Until that time, the possibility of these enemy troops being used for a surprise stroke had to be taken into consideration. The east coast littoral was considered the most likely route of approach. Smith was of the opinion, however, that an amphibious landing should be made in strength, if at all. And there the matter rested.[53] [53] Smith, _Notes_, 1339. _1st MAW Moves to Bofu_ During the operations of the first few days the Marine ground forces had to depend for air support on FEAF planes sent by JOC. The 1st Marine Aircraft Wing had its hands full at this time with housekeeping activities. Work began at Bofu (Map 3) on 20 January as a Seabee detachment arrived with its graders and bulldozers. They were assisted by details of Marines from MAG-33.[54] [54] This section, unless otherwise stated, is based on the January historical diaries of the following organizations: 1st MAW; MAG-33; MAG-12; VMF-312; VMF-214; VMF-323; VMF(N)-513; VMF(N)-542; MWSS-1; FMFPac. Another source is _PacFlt Interim Rpt_ No. 2, II, 969. The job went ahead with typical Seabee efficiency. While specialists installed plumbing for the galleys and barracks, other crews graded taxiways, laid pierced steel planking, and poured concrete to patch up runways, parking ramps, and warmup aprons.