(NRDL) for CASTLE, This involved the use of about 100 dan bucys planted over 360 degrees out to a radius of fifty miles from ground zeros. CINCPACFLT objected to the plan as originally conceived, how~ ever, for it implied a problem in providing for security of the area, It was believed that the small buoys scattered about would create potential radar targets which could easily be mistaken for submarine snorkels. After many attempts to overcome this limitation, tests of newly developed equipment in November, 1953, were conducted succesefully and the system waa approved by CINCPACFLT. The equipment devised involved the installation of low frequency radio transmitters in the buoys, with the frequency range of radio direction finders installed in the DDE's, in patrol aircraft, in ths PC, and in the SIF's likely to be employed in the project. The project, desig- nated Project 2.5a under Task Unit 13 of the Scientific Task Group, was considered vital and together with the other fallout projects had been given the highest priority of all DOD test programs by AFSWP, Another planning problem for the Navy Task Group occurred in procurement of small craft for special purposes. A request was made for an *L" boat for use by the Underwater Detection Units but eince none was available, an LCM was modified for the task—that of maintaining a hydrophone system at the Eniwetok Lagoon entrances. Two additional modified LCM's were required to be included in the Task Group 7.3 Boat Pool. One was to be used in layingand recover= ing buoys in underwater pressure time-reasurement studies and the other was to be used in Scripps Institute of Oceanography studies 78