taking into account steaming times, time required for laying, and drift and set of the currents, were prepared by the project for each shot in which it carticipated. They were then forwarded to the Naval Task uroup for approval and incorporation into their event plan. Project personnel accompanied the ships on their missions to advise and assist in the handling of samples and employment of project equipment. 2.3.2 Rehearsals Arrangements were made with the Task Force to schedule ship and aircraft support for pre-operation rehearsals for the following purposes: (a) To indoctrinate personnel in the process of laying and (ob) To test the radio identification and location systems to (c) To obtain infcrmation on current velocities in the ocean (2) To test radio transmission from the buoys for compatability retrieving buoys and rafts and in the handling equipment at sea, be used. and mounting of project about the two test atolls. with other trconsmissions used throughout the Task Force. In the rehearsals a limited number of buoys were laid around the atoll. Location and recovery operations were sturted the following aay. These rehearsals furnished vuluable information regerding various phases of the operection and acquainted the crews of the ships with the problens to be solved. Under normal conditions the rudio transmitter oper: ted successfully. It usually could be detected on the ship's directionfinding gear out to 16 or 20 miles and greatly facilitated locating the buoys. The ocean currents were found to vary gre.tly both as to set and drift. (See Appendix H.) It becume apparent thut the ability to mount the sea phase would be strongly influenced by the sea state. The hand~ linz problem aboard ship, the cterforwance of the buoys 4nd transmitters at sea, &nu the detection and homing problem all were adversely affected as the sea state imcressed. It was concluded that a full array could be placed as plunned only if the seas were relutively caln, snd thet the cut-off point at which buoy operations must be discontinued would be a sea state of four. It was further concluded thut operations in seas approachin.; state four vould result in damege and loss of equipment in some degrea, as well as extending the time required to carry out all phases, The rehearsals showed th:t the loss rate of buoys would probably be greater than anticipated. Thus in the plenning and conduct of the sea phase for euch shot careful consider.tion had to be given to conservation of equinment for the remaining shots in the series, 2Reded Shot Participation At the start of CASTLE, 124 buoys completely equinped with radiotransmitters and sampling devices were available, ‘Twenty of these units less radiotransnitters were used to augment the sampling program at cikini following the destructicn of Project 2.5a equipment and facilities after Shot 1, The disposition of the buoys during the sea phase 2 Se