POSITIONING STANCHIONS IN THE ARRAY 



A center reference stanchion was jetted into the 

 bottom 7 35 feet from the oceanographic tower. A 222 -foot 

 length of ^~ inch- diameter cable (radius cable) was tethered 

 to this center stanchion by means of a 3 -inch ring which 

 permitted free movement of the cable around the center 

 point. Station 1 was established by stretching this cable 

 along a magnetic north course and jetting-in the base 

 pipe section. Surveying of stations 1 through 13 is 

 depicted in figure 6. 



With the completion of station 1 3, a full quarter of 

 the circle had been formed. At this point, station 1 3 was 

 considered to be station 1 for the next quarter circle and 

 the process was repeated. In order to obtain the greatest 

 possible accuracy, the divers swam the entire length of 

 cables such as the radius cable and the longer chord cables 

 each time they were used. This process expended a great 

 deal of time, but it assured that the cables were not snagged 

 on rocks, debris, or marine organisms. 



It has been estimated that each station can be surveyed 

 to an accuracy of less than 1 percent error by following 

 these procedures. 



15 



