33°20' 



Figure 3. Chart of operating area off Southern California. 



The third visit to the Series 1 1 1 site was once again conducted aboard 

 the USNS Gear. This time a single-point moor was used to hold the ship in 

 the vicinity of the desired test site. Tests SC-17 through SC-29 were success- 

 fully completed, and the device was found to perform very satisfactorily. 



All of the tests were performed and the sediment cores recovered at 

 the Series 1 1 1 site within a one-half-mile-diameter circle. Tests SC-1 7 through 

 SC-29, performed while the ship was at anchor, are located within a circle 

 100 to 200 feet in diameter. 



During a fourth cruise conducted aboard the Marine Mineral Technology 

 Center ship Virginia City, a converted ATF, tests SM-1 through SM-5 were per- 

 formed at the Series IV site in 6,000 feet of water. The ship was operated in a 

 drifting mode during testing. All of the tests except SM-5 and the two sediment 

 cores taken at the site fall within 1,000 feet of the previously given location of 

 the test site. Test SM-5 falls within 2,000 feet of the center of the site. 



Navigation control during all the tests was provided by the LORAC-B 

 precise navigation system. The repeatability of this system in the two test 

 areas is estimated to be from 50 to 100 feet, which exceeds the accuracy with 

 which the position of the device was able to be determined with respect to the 

 location of the support vessel. 



