This was the point of departure for Division planners. They maintained that Wolmi-do was the key terrain feature, and that it should be secured first in a separate landing. The logical course, according to the Marines, would be to utilize the morning high tide for the seizure of this island commanding the waterfront. The enemy would be given the whole day in which to prepare for the attack on the mainland; but the Landing Force could also utilize this period for cleaning up Wolmi-do and moving in supporting artillery. It was typical of the harmony prevailing between the two planning groups on the _Mount McKinley_ that PhibGru One immediately accepted the concept of a double-barreled attack. The rub was that a night approach would be necessary to assault Wolmi-do at 0600 on the morning high tide, and the Navy doubted the feasibility of a movement of the slow-moving and unmaneuverable APAs, AKAs, and LSTs through winding, mud-lined channels in the darkness. At length a compromise was reached with the decision to employ DD, APD, and LSD types primarily, which were more maneuverable in addition to being equipped with radar navigational instruments.[97] [97] This summary of Landing Force planning is based upon: 1st MarDiv _SAR_, basic rpt; MarCorps Board _Study_, v. I, II-B, 13–16; O. P. Smith, _Notes_, 58–62; PacFlt _Interim Rpt No. 1_, XV: Able Able, 6–7. The morning landing on Wolmi-do was to be made with a single battalion of the 5th Marines, to be designated by the Brigade. On the mainland the remaining two battalions would land with the evening high tide on RED Beach, just north of the causeway connecting the island with the city, while two battalions of the 11th Marines landed in support on Wolmi-do. Meanwhile the 1st Marines was to hit BLUE Beach, southeast of the urban area. And after driving rapidly inland to consolidate their positions before nightfall, the two Marine regiments were to make a junction in the morning and seize the beachhead while the 17th ROK Regiment (later replaced by 1st KMC Regiment) mopped up the city streets. Marine G-4 planners suggested one of the most daring of all the calculated risks. This was the decision to use LCVPs for the RED Beach landings because their comparative speed would clear the landing area for the beaching of eight LSTs--all that could be crammed into the narrow confines of this strip of urban waterfront. Each was to be loaded with ammunition, rations, water, and fuel. Obviously these Navy workhorses, nicknamed “large slow targets”, would be easy marks for NKPA shore guns, but this was a chance that had to be taken if the assault troops were to be adequately supplied. There was not time, of course, to unload and retract the ships during the period of evening high tide. They must be unloaded during the night and taken out on the morning tide.