EL 



U 



ectrical Recording C\ 



jndulum for Indicating f*\ 

 ooring-Line Angle — * \ 



El 



Pe 



Mooring- 



\ 



\ 



i T \ !!V 



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Water Surface 



Direction of 





-U-v 



Buoy Release and 

 Mooring-Line Reel- 



Channel Bottom 



Figure 1 - Path of Current-Indicator Buoy As the Buoy Rises to the 

 Surface After Being Released from the Bottom of the Channel 



DESCRIPTION OF THE MODELS 



Three different l/3-scale models and one full-scale model were 

 tested for resistance in the deep-water basin of the Model Basin. The con- 

 struction of the models is as follows: 



The l/3-scale model of Buoy 1 is a sphere 5 1/3 inches in diameter, 

 with a projecting ring 6 inches in outside diameter around the vertical trans- 

 verse equator. When the buoy was towed the ring was normal to the direction 

 of motion. Protruding 1 1/2 inches from the front of the sphere, forward of 

 the ring, was a pin 1/32 inch in diameter, simulating the mooring line; see 

 Figure 2. Provision was made for the pin to be placed at 10, 20, or 30 de- 

 grees from a vertical plane through the center of the sphere. 



The 1/3-scale model of Buoy 2 is a sphere 5 1/3 inches in diameter 

 with a projecting ring 6 inches in outside diameter. This buoy was fitted 

 with a bail for mooring, which necessitated placing the ring aft of the 

 vertical transverse equator; see Figure 3. 



