Figure 8. Current meter with inner tube flotation 

 collar attached just prior to launching. 



out and secured on the buoy deck. Tlie current 

 meters were turned on, and the safety lanyards 

 were removed from the release devices. 



Table 1 is a comparison of the components 

 used on the 1970-71 arrays. 



Setting the Array 



Just prior to launching the array, the EVER- 

 GREEN conducted a bathymetric survey of the 

 mooring site. A suitable site was chosen and 

 marked with a reference buoy. The two prime 

 factors considered in site selection were water 

 depth and a relatively flat bottom contour. The 

 reference buoy was identical to the surface float 

 used with parachute drogues dej^loyed by IIPRS 



(Wolford, 1966). They were moored with poly- 

 propylene line and anchored with approximately 

 50 pounds of chain. 



To set the array, the surface float was swung 

 o\er the side and placed in the water (Figure 

 9). Then as the EVERGREEN backed down 

 slowly, the line and instruments were payed out 

 by hand (Figure 10). A small amount of stern- 



FiGURE 9. Surface buoy being swung over the side. The 

 instruments, line, and anchors are layed out on the 

 buoy deck of the USCGC EVERGREEN. 



Figure 10. Instrument and line being payed over the 

 side as the ship backs down. 



way on the ship kept the mooring line under 

 enough tension to prevent kinking while the 

 anchor was suspended in the port chain stopper. 

 When the EVERGREEN was in position, the 

 anchor was released from the chain stopper. 



When the anchor reached the bottom, the acous- 

 tic release was interrogated to determine if it 

 was still fimctioning properly. The surface float 

 and the reference buoy were watched for about 

 three hours to determine if there was any rela- 

 ti\-e motion between them which would have in- 

 dicated that either the reference marker or the 

 array was dragging anchor. During this time, 

 the position of the mooring site was determined 

 using the best methods available. In 1970, 

 LORAN A and C were used, while in 1971 

 NAVSAT fixes were also available. 



Recovering the Array 



In 1970, recovery operations had to be sched- 

 uled when the time release was set to fire. This 

 pre\ented rescheduling reco^•ery if the weather 

 was adverse or other operations (SAR) pre- 

 vented being on station when the release fired. 

 In 1971, the use of acoustic releases j^ermitted 



13 



