) #15< So Either of the two prospective channels described above vill be adequate for LCU access at high slack water when the lagoon outflow current is decreased. Either channel will be directly into the wind and the best direction for shallow draft craft. Once the reef is broached with the first large shot the current in Pokaakku passage will essentially be sero at all tide stages and small craft can enter at any time necessary during the daylight. db. Triangulation Survey It is probably advisable to execute a fairly precise survey at least to an extent which would allow establishment of bench marks and markers for barge positioning. It should be pointed out that the precision of the placement of zero points does not require any greet accuracy since all diagnostics will be zeroed in visually from the ship to marker lights on the barges. Ce Estuarial Oceanographic Survey “No actual measurement date of currents exists for Taongi atoll. It is deened necessary, for the veasons set forth in connection with the fallout discussion under Item 4 above, to accumulate data on the surface currents vithin the lagoon, their direction, the depths of eny subsurface curreat return paths, @ check on the eccuracy of the soundings as shown presently on the U. S. Navy Hydrographic Survey charts, and the currents across the reef. At the present time two Scripps Institution of Oceanography personnel are attempting to accumulate what meager data can bs obtained in a very short three day visit. d. Channels Within Lagoon Course lines for navigation within the lagoon must be surveyed and tied into the triangulation survey. A channel met be cleared to permit barge movement up the lagoon to the first zero point and buoys and range marks installed if necessary. e. Beachhead and Living Facilities The requirement for @ beachhead end living facilities is mandatary to accomplish necesesry work ashore prior to the first shot, but it should be remembered that the operations plenning should take into account the fact that living facilities mast be evacuated befare firing and will not be required agein ashore. Recent conversations with T. G. 7.5 representatives have indicated the possibility of an APL type barge being used for housing after a channel has been opened, and since the installetions are so minimal this method of providing aceannodations may prove the most econanical. f. Communications Since no need exista for personnel to man stetions or live ashore efter the first shot it is indicated that a military communications link much as was used during the post Crossroads Bikini re-entry at Tare should be considered. Such @ link would provide commmicatioas to Enivetok end it is believed that no need would exist for the transmittal of classified information during the construction phase.