As is evident from this list, Task Group 7.3 was presented with a diverse mission. Such problems as the security of the danger area; intra-and inter-atoll transportation; communications; ship and small craft modification; aids to navigation and buoy systems; and transportation of the special devices were all of paramount concern to the Navy Task Group. | The first Navy operational effort on behalf of CASTLE had come shortly after the firm decision to utilize Bikini in addition to Eniwetok for the CASTLE tests, Naval support was provided at this time (September, 1952) by diverting the USS LST 1126 froma portion of her planned IVY mission to inter-atoll cargo lifts to B i; by scheduling two Eniwetok-Bikini round trips by the LSD; and by scheduling weekly PEM flights between Eniwetok and Bikini. At the completion of Operation IVY in November, 1952, disposi- tion of the naval forces, personnel, and materials employed for IVY was made, as has been indicated, with further CASTLE use in mind. By the time the Navy Task Group staff was reestablished in Washing~ ton after IVY, the CASTLE postponement from Fall, 1953, to Spring, 1954, became known and a change of tempo occurred in Task Group 7.3 planning. One of the principal efforts of the Task Group during this early period following IVY was in connection with the overhaul of navigational aids at Bikini Atoll. The move to Bikini meant a build-up of certain facilities at the atoll for it had not been in use since CROSSROADS, The inactivityat Bikini meant that there had been no maintenance of the buoyage system and rehabilitation of 75