to locate local interference—were made during the period January-~ March, 1953. Upon CTG 73 request, a survey was then made of the communication support which would be required of the AGC by CJTF SEVEN, by the JIF SEVEN Weather Central, and by Task Groups 7.1 and 7.4 as well as any other elements of the Task Force to be em barked. The information thus gained was then passed on for action to COMPHIBTRAPAC and the USS ESTES (AGC-12). Equipment checks and communications tests were effected during Task Group 7.4's Exercise TIGERCAT off San Diego in October, 1953, with CJTF SEVEN, CTC 7.3, and CIG 7.4 aboard. The operation simulated a CASTLE shot and serv- ed, among other objectives, to point out certain deficiencies, These difficulties were partially corrected and by 18 January 1954, the ESTES was ready to proceed to the forward area. (Additional infor- mation on communication difficulties aboard the ESTES is contained in Appendix C.) The matter of physical security gave rise to certain problems for Task Group 7.3. Enlargement of the danger area to include two atolls 180 miles apart meant an increase in the complexity of the security problem. In December, 1952, CINCPAC, having the security responsibility for the PPG, requested CJTF 132's report on the secur=- ity aspects of Operation IVY as well as recommendations for CASTLE. CUTF 132, in turn, requested cpinions and recommendations from CTG 132.3. The basic recommendation which resulted was that security forces for CASTLE be of the same strength and composition as existed during IVY with an augmented underwater detection unit and certain additional measures for the protection of Bikini Lagoon. 80