EXPERIMENTAL DETERMIMTION OF THE TRANSLATIOML 

 STABILITY OF A TETHERED BUOY IN DEEP WATER 



P. R. Wessel 

 Research Physicist 



and 



E. S. Dayhoff 

 Supervisory Physicist 



A submerged instrument platform, with a high degree of 

 stability is required for m any oceanographic and military 

 programs which are conducted in deep water. We have conducted 

 a test of a submerged buoyant system in the underwater tracking 

 range in the Virgin Islemds. The buoy was a sphere four feet in 

 diameter tethered by a single mooring line at a depth of 600 ft. 

 in 1900 ft. of water. A self-contained pinger unit attached 

 to the buoy was monitored by the tracking remge for a period of 

 k2 hours and its position accurately determined. 



Preliminary estimates of the motion to be expected, based 

 on very limited deep water current measurements in the area, are 

 compared with the e^qperimental results. The motion of the buoy 

 was primarily in response to tidal currents. The results can be 

 readily extrapolated to systems of a similar natvire when the 

 physical dimensions of the system and the approximate magnitude 

 of the current are known. 



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